Pediatrics: UWorld

Question 1

What is the most common cause of hip pain in children?

Answer 1

Transient synovitis

This is treated with rest and ibuprofen.

Question 2

What is the most common cause of ambylopia (lazy eye)?

Answer 2

Strabismus

Other causes include errors of refraction and opacity of media along the visual axis.

Question 3

What should be suspected when a well-appearing neonate presents with painless bloody stools?

Answer 3

Milk- or soy-protein proctocolitis

Rectal bleeding should stop within 2 weeks of elimination of dietary dairy and soy products.

Question 4

What is the most appropriate antibiotic therapy for bacterial meningitis in an infant < 28 days old?

Answer 4

Ampicillin + Gentamicin

or

Ampicillin + Cefotaxime

The most common causes of bacterial meningitis would be Escherichia coli, group B streptococcus, and Listeria monocytogenes. This antibiotic regimen would not provide appropriate bacterial coverage for an infant age > 28 days.

Question 5

When does colic typically present and when does it resolve?

Answer 5

1. Presents within first 3 weeks of life
2. Resolves by 4 months of age

Question 6

What diagnosis should be suspected in children who develop isolated thrombocytopenia after a viral infection?

Answer 6

Immune thrombocytopenia

This is a relatively benign condition. There is some controversy regarding the treatment, but in general, corticosteroids are the drugs of choice in all age groups for thrombocytopenia less than 30,000/mm³, and/or for severe symptoms. Patients with a platelet count of more than 30,000/mm³ usually have very few symptoms and do not require treatment.

Question 7

What has been shown to reduce the morbidity and mortality rates of patients with measles through immune enhancement?

Answer 7

Vitamin A

It also helps the gastrointestinal and respiratory epithelium to regenerate.

Question 8

What is the most common cause of urinary tract obstruction in newborn boys?

Answer 8

Posterior urethral valves

Classic findings on prenatal ultrasound include bladder distension, bilateral hydroureters, and bilateral hydronephrosis.

Question 9

New onset hypertension in a child with a bruit or venous hum heard at the costovertebral angle are suggestive of what diagnosis?

Answer 9

Fibromuscular dysplasia

The most common cause of secondary hypertension in children is fibromuscular dysplasia. It is responsible for approximately 20% of all cases of renal hypertension. Physical examination reveals a hum or bruit in the costovertebral angle due to well-developed collaterals. The right renal artery is more affected than the left. Angiogram will reveal the “string of beads” sign to the renal artery.

Question 10

Which cyantotic congenital heart defect is characterized by left axis deviation on electrocardiogram and decreased pulmonary markings on chest radiograph?

Answer 10

Tricuspid valve atresia

The decreased pulmonary markings on chest radiograph are due to hypoplasia of the right ventricle and pulmonary outflow tract.

Question 11

What diagnosis fits the following description?

This is the most common benign vascular proliferation in adults, and appears as a small, bright red, cutaneous papule that appears in patients during adulthood.

Answer 11

Cherry hemangioma

This consists of dilated capillaries and post-capillary venules in the papillary dermis and do not regress spontaneously.

Question 12

The following findings are suggestive of what diagnosis?

1. Hypoplastic fingers/nails
2. Cleft lip/palate

Answer 12

Fetal hydantoin syndrome

Pregnant women on phenytoin during their last trimester often receive prophylactic vitamin K to prevent neonatal bleeding as phenytoin may increase the rate of fetal vitamin K degradation.

Question 13

What presents a few hours after birth as scalp swelling limited to one cranial bone?

Answer 13

Cephalohematoma

This is a subperiosteal hemorrhage. Most cases do not require any treatment and resorb spontaneously within 2 weeks to 3 months, depending on the size.

Question 14

The following findings on electrophoresis are consistent with what diagnosis?

1. Hemoglobin A: 50-60%
2. Hemoglobin S: 35-45%
3. Hemoglobin F:

Answer 14

Sickle Cell Trait

Most patients with sickle cell trait lead normal, healthy lives. Painless hematuria (resulting from sickling in the renal medulla) is the most common complication. Isosthenuria (impairment in concentrating ability) is also common and can present as nocturia and polyuria. Less commonly, there may be an increased risk of urinary tract infections, particularly during pregnancy. Splenic infarctions are uncommon but can occur at high altitudes.

Question 15

What is the inheritance pattern of Marfan Syndrome?

Answer 15

Autosomal Dominant

It results from mutations of the fibrillin-1 (FBN1) gene.

Question 16

The diagnosis of laryngomalacia is confirmed by what means?

Answer 16

Flexible laryngoscopy

This shows collapse of the supraglottic structures during inspiration. Laryngomalacia usually peaks at age 4-8 months, and then self-resolves by age 18 months.

Question 17

Where do 90% of Medulloblastomas occur in children?

Answer 17

The vermis (cerebellum)

Question 18

The following signs/symptoms are characteristic of what diagnosis?

1. Diarrhea
2. Dermatitis
3. Dementia

Answer 18

Pellagra (Niacin deficiency)

• Patients with pellagra typically present with gastrointestinal complaints (nausea, abdominal pain, or epigastric discomfort) along with glossitis and watery diarrhea. The characteristic dermatitis seen in pellagra occurs in sun exposed areas and resembles a sunburn; it is also typically bilateral and symmetric. As the rash progresses, the skin becomes hyperpigmented and thickened. Mental status changes can range from poor concentration to irritability, aggressiveness, and dementia. Death can occur in severe niacin deficiency if not treated with niacin replacement.*
• Niacin = vitamin B₃*

Question 19

What is the treatment of choice for the initial therapy of absence seizures?

Answer 19

Ethosuximide or Valproic acid

Ethosuximide affects the thalamic neurons by working against calcium currents. The possible side effects are drowsiness, nausea, vomiting, hyperactivity or sleep disturbance. Ethosuximide is not useful for the treatment of generalized tonic-clonic and partial epilepsy.

Question 20

The following findings are consistent with what diagnosis?

1. Sore throat
2. Hyperemic and edematous oropharyngeal mucous membranes
3. Cheilitis
4. Stomatitis
5. Glossitis
6. Normocytic-normochromic anemia
7. Seborrheic dermatitis
8. Photophobia

Answer 20

Riboflavin (Vitamin B₂) deficiency

This is rare in industrialized nations, but has been documented in regions of the world with severe food shortages.

Question 21

What is a contraindication to administration of the rotavirus vaccine?

Answer 21

Infants with a history of intussusception

These infants should not recieve the vaccine, as it is associated with a small risk of intussusception.

Question 22

Sudden vasomotor collapse and skin rash due to adrenal hemorrhage in a patient with meningococcemia is characteristic of what condition?

Answer 22

Waterhouse-Friderichsen syndrome

The condition carries an almost 100% mortality.

Question 23

What usually presents with bilious vomiting a few hours after the first newborn feeding?

Answer 23

Duodenal atresia

It is usually associated with other congenital anomalies, and can be a feature of Down’s syndrome.

Question 24

What uncommon complication of acute otitis media is characterized by serous liquid-filled blisters on the tympanic membrane?

Answer 24

Bullous myringitis

Question 25

What viral infection in children is mild and characterized by low-grade fever, tender lymphadenopathy, and a maculopapular rash that spreads cephalocaudally?

Answer 25

Rubella ## Footnote *Vaccination is important to prevent infection of vulnerable pregnant women due to the risk of debilitating congenital rubella syndrome.*

Question 26

What is the treatment of phenylketonuria?

Answer 26

A low phenylalanine diet ## Footnote *Small amounts of phenylalanine are still necessary for growth and development. High-protein foods should be avoided. Early diagnosis and treatment can improve the prognosis, with most (treated) patients having normal mental development and a normal life span.*

Question 27

What is the treatment for Kawasaki disease?

Answer 27

Aspirin and intravenous immunoglobulin ## Footnote *Although Kawasaki disease is self-limited, treatment with aspirin and intravenous immunoglobulin should be started within 10 days of fever onset to prevent cardiac complications. A baseline echocardiography should be performed in all patients with suspected Kawasaki disease and repeated 6-8 weeks later to monitor for any changes.*

Question 28

What is the inheritance pattern of phenylketonuria?

Answer 28

Autosomal recessive ## Footnote *The pathology involves a deficiency in phenylalanine hydroxylase, the enzyme that breaks down phenylalanine into tyrosine. This deficiency leads to the accumulation of phenylalanine and its metabolic products in the blood and body tissues (particularly in the brain).*

Question 29

A mutation in the fibrillin-1 (FBN1) gene is the cause of what condition?

Answer 29

Marfan syndrome ## Footnote *This is an autosomal dominant disorder.*

Question 30

Premature adrenarche is characterized by the isolated appearance of axillary hair before the age of 6 years and results from what?

Answer 30

Premature androgen secretion of the adrenal glands ## Footnote *The condition is generally benign and has no clinical significance. Premature pubarche (pubic hair before the age of 8) on the other hand is more alarming, as it is associated in 50% of cases with a CNS disorder.*

Question 31

What distinguishes otitis media with effusion from acute otitis media?

Answer 31

Otitis media with effusion lacks acute inflammatory signs ## Footnote *These signs include fever, bulging of the tympanic membrane, and erythema of the tympanic membrane.*

Question 32

What 6 maternal factors are a contraindication to breastfeeding?

Answer 32

1. Active untreated tuberculosis (mothers may breastfeed after 2 weeks of antituberculin therapy) 2. HIV infection (in developed countries where formula is readily available) 3. Active abuse of street drugs or alcohol 4. Herpetic breast lesions 5. Varicella infection (between 5 days prior to delivery to 2 days after delivery) 6. Certain medications (including chemotherapy)

Question 33

In a newborn, an absent moro reflex in the setting of intact biceps and grasp reflexes is indicative of what diagnosis?

Answer 33

Clavicle fracture ## Footnote *Absent moro, biceps, and grasp reflexes would raise concern for C5-C7 damage (eg Erb-Duchenne paralysis). An absent moro reflex in the setting of preserved biceps and grasp reflexes make nerve injury unlikely. Physical exam will most likely reveal crepitus and irregularity in the region of the clavicle.*

Question 34

What disease classically presents as a young boy with eczema, thrombocytopenia, and recurrent infections with encapsulated germs?

Answer 34

Wiskott-Aldrich Syndrome (WAS) ## Footnote *This is an X-linked recessive disease caused by a defective gene encoding for Wiskott-Aldrich syndrome protein (WASP). The initial manifestations often present at birth and consist of petechiae, bruises, bleeding from circumcision, or bloody stools. Immunologic findings include low IgM levels, high IgA and IgE levels, poor antibody responses to polysaccharide antigens, and moderately reduced number of T cells and platelets.*

Question 35

The following findings are characteristic of what diagnosis? 1. Anemia 2. Short stature 3. Webbed neck 4. Cleft lip 5. Shielded chest 6. Triphalangeal thumbs

Answer 35

Diamond-Blackfan anemia ## Footnote *The primary pathology is an intrinsic defect of erythroid progenitor cells which results in increased apoptosis. 90% of cases are diagnosed within the first year of life, with the average age of diagnosis being 3 months.*

Question 36

What type of hypersensitivity results from IgG or IgM specifically reacting to cell-bound antigens, and then activating complement resulting in cell damage?

Answer 36

Antibody-mediated (type II) hypersensitivity ## Footnote *Examples of these types of reactions are immune hemolytic anemia and Rh hemolytic disease in the newborn.*

Question 37

What is the second most common primary bone malignancy?

Answer 37

Ewing sarcoma ## Footnote *The incidence is highest in adolescent males and up to 20% of patients may have systemic symptoms. X-ray shows an osteolytic lesion with periosteal reaction that produces layers of reactive bone, giving the classic "onion skin" appearance.*

Question 38

What is the treatment for whooping cough (bordetella pertussis infection)?

Answer 38

Macrolide antibiotics ## Footnote *This includes azithromycin, clarithromycin etc. Antibiotics are most effective during the catarrhal (1st) phase and less effective in the paroxysmal (2nd) and convalescent (3rd) phases. The first (catarrhal) phase includes nonspecific symptoms (malaise, mild fever, cough, rhinorrhea) and lasts 1-2 weeks. The 2nd (paroxysmal) phase occurs next and usually presents with severe paroxysms of coughing spells that can lead to post-tussive emesis. The 3rd (convalescent) phase typically presents with gradually decreasing frequency and severity of cough. The total duration of all 3 phases is usually about 3 months if untreated.*

Question 39

Recurrent self-limiting episodes of vomiting and nausea in a child in the absence of any apparent cause is suggestive of what diagnosis?

Answer 39

Cyclical vomiting ## Footnote *The etiology of this condition is unclear, however, its incidence is high in children whose parents have a history of migraine headaches. Treatment consists of anti-emetics and reassurance of the parents.*

Question 40

What type of hypersensitivity results from the formation of complexes between antigens and IgG or IgM that nonspecifically activate the complement cascade and other inflammatory processes?

Answer 40

Immune complex-mediated (Type III) hypersensitivity ## Footnote *Examples of this reaction are serum sickness and the Arthus reaction.*

Question 41

What life-threatening syndrome presents with recurrent bacterial, viral, and fungal infections, absent lymph nodes and tonsils, lymphopenia, and an absent thymic shadow?

Answer 41

Sever combined immune deficiency ## Footnote *The patient will also have abnormal T, B, and natural killer cell enumeration by flow cytometric analysis.*

Question 42

What kind of seizure has the following characteristics? 1. Loss of consciousness 2. Can have aura 3. Motor automatisms (I.E. chewing, swallowing, sucking) 4. Sometimes have bilateral motor findings

Answer 42

Complex partial seizures

Question 43

What is the most common complication of a supracondylar humerus fracture?

Answer 43

Entrapment of the brachial artery ## Footnote *This will result in loss of the radial artery pulse. After reduction of the fracture, the radial pulse must be assessed.*

Question 44

What is the treatment for Guillain-Barre syndrome?

Answer 44

Plasmapheresis or human immunoglobulin ## Footnote *Recovery follows the inverse order of the initial progression of the disease.*

Question 45

Traction apophysitis of the tibial tubercle is known as what?

Answer 45

Osgood-Schlatter disease ## Footnote *Radiographic findings include anterior soft tissue swelling, lifting of tubercle from the shaft, and irregularity or fragmentation of the tubercle.*

Question 46

New-onset hearing loss or chronic ear drainage despite antibiotic therapy are typical childhood presenting symptoms of what condition?

Answer 46

Cholesteatoma ## Footnote *Cholesteatomas in children can either be congenital or acquired secondary to chronic middle ear disease. Granulation tissue and skin debris may be seen within retraction pockets of the tympanic membrane on otoscopy.*

Question 47

What diagnosis should be suspected in a child who presents with an ascending polyneuropathy one week after an apparent viral infection?

Answer 47

Guillain-Barre syndrome ## Footnote *The underlying pathology involves mainly the peripheral motor nerves, although sensory and autonomic nerves may also be affected.*

Question 48

What kind of seizure has the following characteristics? 1. No loss of consciousness 2. Feeling of familiarity (deja-vu) 3. Can have aura 4. Patient may remember event well

Answer 48

Simple partial seizure

Question 49

What is the most common cause of secondary hypertension in children?

Answer 49

Fibromuscular dysplasia ## Footnote *It is responsible for approximately 20% of all cases of renal hypertension.*

Question 50

The United States Preventive Services Task Force (USPSTF) recommends vision screening for children aged 0-5 years, primarily to identify what 3 abnormalities?

Answer 50

1. Strabismus 2. Ambylopia 3. Refractive errors ## Footnote *Early diagnosis and treatment are being emphasized, because poor visual acuity resulting from the above conditions may impair a child's future academic performance and self-image, and may even lead to blindness.*

Question 51

What finding is diagnostic of neurofibromatosis type 2?

Answer 51

Bilateral acoustic neuromas

Question 52

What classically presents as postprandial nonbilious emesis at ages 3-6 weeks?

Answer 52

Pyloric stenosis

Question 53

What presents with intermittent episodes of severe abdominal pain and is the most common cause of intestinal obstruction in children age 6-36 months?

Answer 53

Intussusception

Question 54

Pappenheimer bodies are iron-containing inclusion bodies found in peripheral red blood cells. They result from phagosomes that engulf excessive amounts of iron and are typically seen in what condition?

Answer 54

Sideroblastic anemia

Question 55

What is the most common cause of pediatric myocarditis?

Answer 55

A viral illness (especially Coxsackievirus B and adenovirus) ## Footnote *The pathogenesis is thought to be direct viral injury and autoimmune inflammation that leads to myocyte necrosis with subsequent impairment of systolic and diastolic function.*

Question 56

The following signs/symptoms are characteristic of what diagnosis? 1. Sensorineural deafness 2. Developmental delay 3. Cataracts 4. Hepatosplenomegaly 5. Purpura

Answer 56

Congenital rubella syndrome

Question 57

What disorder is characterized as an autosomal recessive disorder that involves degeneration of the anterior horn cells and cranial nerve motor nuclei?

Answer 57

Werdnig-Hoffman syndrome ## Footnote *It is a cause of "floppy baby" syndrome (the other cause is infant botulism).*

Question 58

What diagnosis fits the following description? A benign vascular tumor of childhood that appears during the first few weeks of life, initially growing rapidly, and typically regressing by 5-8 years of age.

Answer 58

Strawberry hemangioma ## Footnote *This tumor is composed of capillaries separated by connective tissue.*

Question 59

The following signs/symptoms are characteristic of what diagnosis? 1. Barky cough 2. Fever 3. Rhinorrhea 4. Congestion

Answer 59

Croup (laryngotracheobronchitis) ## Footnote *This is the most common cause of inspiratory stridor in children age 6 months to 3 years. It is most often caused by the parainfluenza virus. It responds to treatment with racemic epinephrine and corticosteroids.*

Question 60

What is the recommended first-line treatment for pertussis?

Answer 60

Macrolide antibiotics for 14 days ## Footnote *Erythromycin, azithromycin, or clarithromycin.*

Question 61

The following signs/symptoms are characteristic of what diagnosis? 1. Mental retardation 2. Blindness 3. Deafness 4. Paralysis 5. Peripheral motor sensory neuropathy 6. Seizures

Answer 61

Krabbe's disease ## Footnote *This is a sphingolipidosis due to a deficiency in beta-galactosidase, which results in a total absence of myelin.*

Question 62

What condition is characterized by defective intracellular killing due to impaired respiratory burst from activated phagocytes?

Answer 62

Chronic granulomatous disease ## Footnote *In this condition, the classic nitroblue tetrazolium test is negative (abnormal). The dihydrorhodamine 123 test is more sensitive and can quantify the severity of illness.*

Question 63

What condition is characterized as an inflammatory, demyelinating condition that causes acute vision loss and pupillary defects?

Answer 63

Optic neuritis ## Footnote *It most commonly affects 1 eye and is associated with multiple sclerosis.*

Question 64

The following findings in a child are consistent with what diagnosis? 1. Fever 2. Dysphagia 3. Drooling 4. Inability to extend neck 5. Muffled voice 6. Trismus (inability to open the mouth completely)

Answer 64

Retropharyngeal abscess ## Footnote *On a normal lateral neck x-ray, the prevertebral soft-tissue space should be narrower than the vertebral bodies. A lateral x-ray showing a widened prevertebral space is suggestive of a retropharyngeal abscess. Due to the proximity of the airway, spine, and major vascular structures, infections in this region are potentially life-threatening. In patients with no signs of respiratory compromise, a computed tomography scan with contrast should be performed to confirm the presence and size of the abscess. The abscess is usually polymicrobial, involving streptococcus pyogenes, staphylococcus aureus, and anaerobes. It occurs most commonly in children age 6 months to 6 years. There is a decreased incidence after age 6 years.*

Question 65

What artery can be compromised by a supracondylar humerus fracture?

Answer 65

The brachial artery ## Footnote *The radial artery pulse must be assessed when the fracture is reduced.*

Question 66

What kind of seizure has the following characteristics? 1. Can have loss of consciousness 2. Bilateral motor findings 3. Can be convulsive or non-convulsive

Answer 66

Generalized seizure

Question 67

The following findings are suggestive of what diagnosis? 1. Craniofacial anomalies (I.E. cleft palate) 2. Thymic hypoplasia 3. Congenital heart disease

Answer 67

DiGeorge syndrome ## Footnote *Newborns with DiGeorge syndrome must be assessed immediately for potentially life-threatening hypocalcemia.*

Question 68

What usually presents in a child less than one month of age as bilious vomiting, abdominal distension, and passage of bloodstained stools?

Answer 68

Midgut volvulus ## Footnote *Volvulus is associated with malrotation of the gut, and can be complicated by perforation and peritonitis.*

Question 69

The following findings are suggestive of what diagnosis? 1. Flat facial profile 2. Slanted palpebral fissures 3. Small, low-set ears 4. Excessive skin at nape of the neck 5. Clinodactyly (bend or curvature of 5th fingers towards 4th fingers) 6. Larger space between the first two toes

Answer 69

Down Syndrome

Question 70

The following signs/symptoms are characteristic of what diagnosis? 1. Ataxia 2. Dysarthria 3. Scoliosis 4. Foot deformities 5. Concentric hypertrophic cardiomyopathy

Answer 70

Friedreich ataxia ## Footnote *This is an autosomal recessive disorder, and its symptoms usually begin before 22 years of age. It presents with neurologic, skeletal, and cardiac manifestations.*

Question 71

What presents with decreased serum concentrations of IgG, IgA, IgM, and IgE, but no absence or decrease in the number of circulating B cells?

Answer 71

Common variable immunodeficiency (CVID)

Question 72

What condition is characterized as an autosomal recessive condition characterized by an excessive number of trinucleotide repeat sequences, resulting in an abnormality of a tocoperol transfer protein?

Answer 72

Friedreich Ataxia ## Footnote *This disorder is progressive with poor prognosis. Most patients are wheelchair bound by the age of 25, with death occurring by 30-35 years of age.*

Question 73

What is the treatment of choice for severe tricyclic antidepressant intoxication?

Answer 73

Sodium bicarbonate ## Footnote *This drug not only helps to correct the acidosis, but also helps to narrow the QRS complex prolongation. A benzodiazepine is given when the patient presents with seizures that require treatment.*

Question 74

Bilious vomiting in the first 2 days of life and a "double bubble" sign on abdominal x-ray are strongly suggestive of what diagnosis?

Answer 74

Duodenal atresia ## Footnote *X-ray shows air trapped in the stomach and the first portion of the duodenum (double-bubble sign) and no distal intestinal gas. Management includes holding enteral feeds, decompression with a naso or oro-gastric tube and surgical repair.*

Question 75

Enuresis, polyuria, and diaper candidiasis in a 4-6 year old is suggestive of what diagnosis?

Answer 75

Type I diabetes mellitus

Question 76

A large thymic silhouette is a normal finding on frontal chest x-ray in children of what age?

Answer 76

\< 3 years old ## Footnote *Opacities in this location in other children should raise concern for pneumonia or malignancy, depending on the clinical context.*

Question 77

Neonatal jaundice with conjugated hyperbilirubinemia is suggestive of what?

Answer 77

Neonatal cholestasis

Question 78

What should be suspected in a patient who presents at birth with equinus and varus of the calcaneum and talus, varus of the midfoot, and adduction of the forefoot?

Answer 78

Clubfoot ## Footnote *Treatment of clubfoot with serial casting should be started immediately.*

Question 79

The following signs/symptoms are characteristic of what diagnosis? 1. Tingling or pins-and-needles of the foot 2. Ascending weakness (from lower extremities, to the trunk, to the upper extremities) 3. GI symptoms, compromised respiration and swallowing, autonomic abnormalities such as dynamic blood pressures/heart rate may be present 4. The final stage may include flaccid paralysis with decreased deep tendon reflexes and nerve conduction velocities indicating demyelinization

Answer 79

Guillain-Barre syndrome ## Footnote *Cerebrospinal fluid analysis reveals significantly elevated protein levels and mildly elevated cells (albumino-cytologic dissociation). The treatment is plasmapheresis or human immunoglobulin. Recovery follows the inverse order of the initial progression of the disease.*

Question 80

Linear deposition of immunoglobulin G on the basement membrane is seen in what disease?

Answer 80

Goodpasture's syndrome ## Footnote *This is caused by antibodies directed against the basement membrane. It typically present with pulmonary hemorrhage and glomerulonephritis.*

Question 81

What is the treatment for chlamydial conjunctivitis or chlamydial pneumonia in a neonate?

Answer 81

14-day course of erythromycin ## Footnote *This is true despite the risk of hypertrophic pyloric stenosis with oral erythromycin.*

Question 82

The following findings are consistent with what diagnosis? 1. Paroxysmal cough (lasting \>2 weeks) 2. Inspiratory whoop 3. Post-tussive emesis

Answer 82

Bordetella pertussis ## Footnote *During the first 4 weeks of illness, the diagnosis is confirmed by cultures and/or polymerase chain reaction of nasopharyngeal secretions. Serology is required in patients with \>4 weeks of symptoms. Treatment with macrolide antibiotics should be initiated based on clinical suspicion without waiting for the confirmatory diagnosis.*

Question 83

Port-wine stains are most closely associated with what?

Answer 83

Sturge-Weber syndrome

Question 84

Heterophile antibody testing is used to diagnose what?

Answer 84

Infectious mononucleosis due to Epstein-Barr virus

Question 85

What presents as microcytic anemia with target cells and teardrop cells on peripheral smear?

Answer 85

Thalassemia trait (thalassemia minor) ## Footnote *The red cell distribution width, total iron-binding capacity, serum iron, and ferriting levels are typically normal. Treatment is not usually needed for mild to moderate anemia.*

Question 86

What disorder is caused by an increased number of CGG repeats?

Answer 86

Fragile X syndrome ## Footnote *This syndrome results from a full mutation in the FMR1 gene caused by an increased number of CGG trinucleotide repeats accompanied by aberrant methylation of the FMR1 gene.*

Question 87

The following characteristics are consistent with what developmental age? 1. Gross motor: Runs, kicks ball 2. Fine motor: Builds tower of 2-4 cubes, removes clothing 3. Language: 10-25 word vocabulary, identifies _\>_1 body part 4. Social/Cognitive: Understands "mine", begins pretend play

Answer 87

18 months

Question 88

An erythematous, scaly, pruritic rash with central clearing is characteristic of what?

Answer 88

Ringworm (tinea corporis) ## Footnote *This is a superficial fungal infection best treated with topical antifungals such as terbinafine.*

Question 89

The following findings are characteristic of what diagnosis? 1. Recurrent bacterial infections of the skin and mucosal surfaces 2. Necrotic periodontal infections 3. Leukocytosis with neutrophil predominance

Answer 89

Leukocyte adhesion defect type 1 *These patients also suffer from delayed separation of the umbilical cord, and they have a complete absence of neutrophils in inflamed or infected tissues.* *This syndrome is caused by deficient expression of CD18, an essential component of certain integrins present on the surface of leukocytes.*

Question 90

Extreme pain, bleeding in the middle ear space, and purple or red hue to the eardrum are characteristics of what?

Answer 90

Hemotympanum (barotrauma or blunt trauma to the ear)

Question 91

What presents in an infant as cyanosis and respiratory distress during feeding that improves when the infant cries?

Answer 91

Bilateral choanal atresia

Question 92

Allergic contact dermatitis is due to what type of hypersensitivity reaction?

Answer 92

Delayed (type IV) hypersensitivity reaction ## Footnote *Erythema, edema, pruritus, tiny vesicles and weepy or crusted lesions 24-48 hours after contact with the allergen.*

Question 93

What is the most common cause of congenital hypothyroidism worldwide?

Answer 93

Iodine deficiency endemic goiter ## Footnote *This is essentially not seen in the United States.*

Question 94

A neonate with what diagnosis is at increased risk of the following complications? 1. Hypoxia 2. Polycythemia 3. Hypoglycemia 4. Hypothermia 5. Hypocalcemia

Answer 94

Small for destational age ## Footnote *The polycythemia results from increased erythropoietin secretion in response to fetal hypoxia. Hypocalcemia is thought to be caused by a decreased transfer of calcium across the placenta. Hypothermia is due to decreased subcutaneous fat and therefore impaired thermoregulation. Hypoglycemia occurs because of decreased glycogen stores.*

Question 95

Patients with galactosemia are at increased risk for neonatal sepsis caused by what organism?

Answer 95

E. Coli

Question 96

What are the 3 contraindications to administration of the diptheria-tetanus-acellular pertussis (DTaP) vaccine?

Answer 96

1. History of immediate anaphylaxis with previous DTAP administration 2. Unstable neurologic disorders 3. History of encephalopathy within a week of administration of the DTaP vaccine

Question 97

The following findings are consistent with what diagnosis? 1. Palpable purpura on lower extremities 2. Arthralgias 3. Abdominal pain 4. Renal disease 5. Immunofluorescence microscopy shows IgA deposition in the kidney

Answer 97

Henoch-Schonlein purpura ## Footnote *This is an immunoglobulin A-mediated vasculitis of the small vessels that is most common in children.*

Question 98

The following signs/symptoms are characteristic of what diagnosis? 1. Angiokeratomas 2. Peripheral neuropathy 3. Asymptomatic corneal dystrophy 4. Kidney or heart failure 5. Thromboembolic events

Answer 98

Fabry's disease ## Footnote *This is a sphingolipidosis that results from a deficiency of alpha-galactosidase.*

Question 99

What should be suspected in a toddler with a firm, smooth, unilateral abdominal mass and hematuria?

Answer 99

Wilms tumor *This is the most common pediatric renal malignancy*.

Question 100

Intravenous pyelography showing bilateral focal parenchymal scarring and blunted calyces is characteristic of what diagnosis?

Answer 100

Chronic pyelonephritis

Question 101

What are the two most common pathogens responsible for causing acute bacteril rhinosinusitis in children?

Answer 101

1. Streptococcus pneumoniae (~30%) 2. Nontypeable haemophilus influenzae (~30%) ## Footnote *The third most common is Moraxella catarrhalis (~10%). Because of increasing beta-lactamase resistance, the treatment of choice is amoxicillin-clavulanic acid.*

Question 102

What is the treatment of choice for seborrheic dermatitis?

Answer 102

1. Moisturizers 2. Antifungals 3. Topical steroids ## Footnote *This is a common pediatric skin conditions characterized a by papular, scaly rash that tends to affect the eyebrows, nasolabial folds, and scalp.*

Question 103

The following signs/symptoms in a child are characteristic of what diagnosis? 1. Headaches 2. Vomiting 3. Visual disturbances 4. Unbalanced gait 5. Trunk dystaxia 6. Horizontal nystagmus 7. Papilledema

Answer 103

Medulloblastoma ## Footnote *The patient presents with posterior Vermis syndrome (truncal dystaxia). Medulloblastoma represents 7% of primary brain tumors, and is the second most common posterior fossa tumor (after cerebellar astrocytoma) in children. It is highly radiosensitive and can metastasize through the CSF tract. Over 90% of medulloblastomas develop in the vermis.*

Question 104

Osteonecrosis in sickle cell patients most commonly occurs in what 2 bones?

Answer 104

Humerus and femur ## Footnote *Osteonecrosis is a common complication of sickle cell anemia due to vaso-occlusion of the bone. It causes significant joint pain and functional limitation.*

Question 105

What disorder should be considered in a patient with mild immunodeficiency consisting of recurrent sinopulmonary and GI infections, and anaphylactic transfusion reaction?

Answer 105

IgA deficiency ## Footnote *Diagnosis may be confirmed by measurement of a low serum IgA concentration with normal serum IgM and IgG levels.*

Question 106

What presents with abrupt onset fever, sore throat, dysphagia, and drooling?

Answer 106

Epiglottitis ## Footnote *Airway obstruction is the most concerning potential complication of epiglottitis, and often requires nasotracheal intubation. In unimmunized children, H. influenzae type b is a likely cause.*

Question 107

What diagnosis fits the following description? A soft, blue, compressible mass up to a few centimeters in size that presents later in life and appears as a large dilated vascular space on light microscopy.

Answer 107

Cavernous hemangioma

Question 108

Pain in the hip of a sickle cell disease patient is characteristic of what?

Answer 108

Aseptic necrosis of the femoral head ## Footnote *This is a common complication of sickle cell disease. It involves occlusion of end arteries supplying the femoral head, bone necrosis, and eventual collapse of the periarticular bone and cartilage. The femoral head has two main sources of blood supply: ascending arteries and the foveal artery, which lie within the ligamentum teres. The foveal artery is patent early in life, but may become obliterated in older patients. This explains why aseptic necrosis of the femoral head is uncommon in children.*

Question 109

What neonatal diagnosis would be made in an infant born to an unimmunized mother following an umbilical stump infection?

Answer 109

Neonatal tetanus ## Footnote *Affected infants initially present in the first two weeks of life with poor suckling and fatigue, followed by rigidity, spasms and opisthostonus.*

Question 110

The following signs/symptoms are characteristic of what diagnosis? _First 2 weeks of life_ 1. Poor suckling 2. Fatigue _Followed by_ 1. Rigidity 2. Spasms 3. Opisthotonus

Answer 110

Neonatal tetanus ## Footnote * Neonatal tetanus is often generalized and invariably fatal, if left untreated. The onset is generally within the first 2 weeks of birth, and is characterized by poor suckling and fatigue followed by rigidity, spasms and opisthotonus. The mortality rate is very high due to apnea (in the first week of life) and septicemia (in the second week).* * Opisthotonus = Hyperextension and spasm of the head, neck, and back*

Question 111

What kind of seizures are treated with lamotrigine?

Answer 111

Mixed seizures ## Footnote *Lamotrigine is used as a first-line agent for mixed seizures, and as a second-line drug for generalized tonic-clonic and partial seizures.*

Question 112

The following findings are consistent with what diagnosis? 1. Massive splenomegaly 2. High lymphocytosis 3. Lymphadenopathy

Answer 112

Prolymphocytic leukemia ## Footnote *This is a chronic lymphocytic leukemia (CLL) variant.*

Question 113

The following findings are characteristic of what diagnosis? 1. Pancytopenia 2. Hyperpigmentation on the trunk, neck or intertriginous areas 3. Cafe-au-lait spots 4. Short stature 5. Upper limb abnormalities 6. Hypogonadism 7. Skeletal anomalies 8. Eye/eyelid changes 9. Renal malformations

Answer 113

Fanconi's anemia ## Footnote *Blood counts start to decrease between 4 and 12 years of age, and the initial manifestation is usually thrombocytopenia, followed by neutropeina, then anemia.*

Question 114

What are the four indications for surgery to repair an congenital umbilical hernia in a child?

Answer 114

1. Hernia persists to the age of 3 or 4 years 2. Hernia exceeds 2 cm in diameter 3. Hernia causes symptoms or becomes strangulated 4. Hernia progressively enlarges after the age of 1-2 years

Question 115

What presents with decreased serum concentrations of IgG, IgA, IgM, and IgE, along with absent or markedly decreased B cells on the smear?

Answer 115

Bruton's agammaglobulinemia

Question 116

What are the screening recommendations for patients with Beckwith-Wiedemann syndrome?

Answer 116

1. Birth to age 4 years: Abdominal ultrasound and alpha-fetoprotein levels every 3 months 2. Age 4-8 years: Abdominal ultrasound every 3 months 3. Age 8 years through adolescence: Renal ultrasound every 3 months ## Footnote *Vigilant surveillance is to rule out the development of Wilms tumor and hepatoblastoma.*

Question 117

What vitamin/nutrient supplement should be started at birth and continued for the first year in an exclusively breastfed preterm infant?

Answer 117

Iron ## Footnote *Preterm infants are at significantly increased risk for iron deficiency anemia. All exclusively breastfed infants should also be started on vitamin D supplementation.*

Question 118

The following findings are consistent with what diagnosis? _At presentation_ 1. Vomiting 2. Hypotonia _Symptoms progress to_ 1. Neurologic features (mental retardation, dystonia, choreoathetosis, spasticity) 2. Gouty arthritis 3. Tophus formation 4. Self-mutilation

Answer 118

Lesch-Nyhan syndrome ## Footnote *Presentation is generally around age 6 months with hypotonia and persistent vomiting. This is an X-linked recessive disorder (all victims of Lesch-Nyhan syndrome are male) resulting from a deficiency in hypoxanthine-guanine phosphoribosyl transferase (HPRT), an enzyme involved in purine metabolism. This deficiency results in increased levels of uric acid and its consequent accumulation in peripheral tissue. Gout is usually seen in patients above 50 years of age, therefore, suspect Lesch-Nyhan syndrome if you see a boy with gout.*

Question 119

What is the most common cause of nephrotic syndrome in patients younger than 16 years of age?

Answer 119

Minimal Change Disease ## Footnote *Light microscopy and immunofluorescence does not usually reveal any change in kidney architecture. Electron microscopy shows diffuse effacement of foot processes of podocytes. Steroids are the treatment of choice.*

Question 120

What organ has the highest morbidity/mortality following hemolytic uremic syndrome?

Answer 120

The kidneys ## Footnote *The toxin released by E. Coli enters systemic circulation and injures the endothelial cells in the kidney.*

Question 121

What typically presents in boys age 4-10 years old with insidious-onset hip or knee pain and an antalgic gait?

Answer 121

Legg-Calves-Perthes (LCP) disease ## Footnote *Initial x-rays may be negative. It can be clinically distinguished from transient synovitis by the duration of symptoms (1-4 weeks for transient synovitis vs \>1 month for LCP).*

Question 122

By the age of 2 years, a child's vocabulary has usually increased to how many words?

Answer 122

150-300 words

Question 123

The following signs/symptoms are characteristic of what diagnosis? 1. Fever 2. Sore throat 3. Pericarditis 4. Erythema marginatum 5. Arthritis 6. Chorea 7. Subcutaneous nodules

Answer 123

Rheumatic fever ## Footnote *This is caused by group A streptococcus.*

Question 124

Breath holding spells are episodes of apnea that are sometimes associated with a loss of consciousness. What is the best approach to a child with such episodes?

Answer 124

Reassure the parents ## Footnote *Breath holding spells are self-limited and should be treated with education and reassurance.*

Question 125

What is the best test for diagnosis of vesicoureteral reflux?

Answer 125

Voiding cystourethrogram (VCUG) ## Footnote *Renal ultrasound is not a sensitive modality for detection.*

Question 126

The following findings in a newborn during the first few weeks of life are consistent with what diagnosis? 1. "Floppy baby" 2. Feeding difficulties 3. Macroglossia (large tongue) 4. Heart failure

Answer 126

Pompes disease (acid maltase deficiency) ## Footnote *This is type II glycogen storage disease. Heart failure occurs due to progressive hypertrophic cardiomyopathy.*

Question 127

The following findings are consistent with what diagnosis? _At birth_ 1. Macrosomia 2. Macroglossia 3. Umbilical hernia/omphalocele 4. Hemihyperplasia 5. Hypoglycemia _Later may develop_ 1. Wilms tumor 2. Hepatoblastoma

Answer 127

Beckwith-Wiedemann syndrome ## Footnote *This is an overgrowth disorder characterized by a predisposition to neoplasms. Most patients have a sporadic or inherited alteration of chromosome 11p15, which includes genes that encode insulin-like growth factor 2, a growth-promoting hormone similar to insulin.*

Question 128

The following findings suggestive of what diagnosis? 1. Prodrome of fever, irritability, and skin tenderness 2. Followed by generalized erythema and superficial flaccid blisters with a positive Nikolsky sign (mild rubbing causes skin to exfoliate)

Answer 128

Staphylococcal Scalded Skin Syndrome ## Footnote *This is caused by exfoliative toxin-producing strains of S. Aureus. It ends with scaling and desquamation of the skin before resolution of the disease process. It typically affects children below age 10 years old, but adults with kidney disease or immune compromise may also be affected.*

Question 129

The following characteristics are consistent with what developmental age? 1. Gross motor: Pulls to a stand, cruises 2. Fine motor: 3-finger pincer grasp, holds bottle or cup 3. Language: Says "dada" and "mama" 4. Social/cognitive: Waves "bye", plays pat-a-cake

Answer 129

9 months

Question 130

What is the treatment of choice for minimal change disease?

Answer 130

Steroids ## Footnote *Patients respond dramatically to steroids. With 4-6 weeks of therapy, over 90% of children demonstrate complete remission with the disappearance of proteinuria.*

Question 131

Which 2 viruses are the most common cause of viral meningitis?

Answer 131

Echovirus and coxsazkievirus

Question 132

Klumpke palsy is a result of damage to which nerves?

Answer 132

C8 and T1 ## Footnote *Klumpke palsy is a rare but potentially permanent complication of shoulder dystocia. Injury to the 8th cervical and 1st thoracic nerves results in hand paralysis and ipsilateral Horner syndrome.*

Question 133

What is the most common pathogen responsible for causing acute, unilateral cervical lymphadenitis in children?

Answer 133

Staphylococcus aureus ## Footnote *Cervical lymphadenopathy is common in children. Lymphadenitis is diagnosed when the lymph node becomes tender and erythematous in addition to bein enlarged. Although there are multiple causes for lymphadenopathy in children, the differential diagnosis can be narrowed by determining if the lymphadenopathy is acute or subacute/chronic, and if it is unilateral or bilateral. Acute, unilateral lymphadenitis in children is usually caused by a bacterial infection.*

Question 134

The following characteristics are consistent with what developmental age? 1. Gross motor: Sits with trunk support, begins rolling 2. Fine motor: Hands mostly open, reaches midline 3. Language: Laughs, turns to voice 4. Social/cognitive: Enjoys looking around

Answer 134

4 months

Question 135

What does a positive Guthrie test signify?

Answer 135

Phenylketonuria ## Footnote *This is a qualitative (coloration) test which can detect the presence of metabolic products of phenylalanine in the urine.*

Question 136

The following signs/symptoms are characteristic of what diagnosis? 1. Fever 2. Headache 3. Vomiting 4. Sore throat 5. Fine pink blanching papules on the neck and upper trunk (12-48 hours after the onset of constitutional symptoms)

Answer 136

Scarlet Fever ## Footnote *This is a toxin-related process, caused by a toxin-producing strain of group A streptococcus. It primarily occurs in children. Skin eruption is said to have a rough, sandpaper-like texture.*

Question 137

Deficiency of galactose-1-phosphate uridyl transferase is characteristic of what diagnosis?

Answer 137

Galactosemia *Galactosemia is not a self-limiting condition. Failure to make an early diagnosis and to intervene can lead to severe and irreversible liver cirrhosis and mental retardation.* *Early diagnosis and treatment have been shown to affect the patient's eyesight. Bilateral cataracts may regress, and the eyesight of most patients are improved or normal.*

Question 138

Which immunodeficiency typically presents at 15-35 years old?

Answer 138

Common variable immunodeficiency (CVID) ## Footnote *The serum concentrations of IgG, IgA, IgM, and IgE, may be decreased, but there is no absence or decrease in the number of circulating B cells.*

Question 139

What is the most common histological type of tumor in children?

Answer 139

Astrocytoma ## Footnote *Approximately 60% of brain tumors in children are infratentorial, 25% are supratentorial, and 15% arise in the midline. Astrocytomas are the most common histological type for both supra- and infra-tentorial groups.*

Question 140

What typically manifests as a well-demarcated, red, indurated, warm, tender plaque on the skin and is associated with constitutional symptoms of fever, chills, and malaise?

Answer 140

Erysipelas ## Footnote *In severe cases, there may be overlying vesicles and bullae. There may also be lymphangitic streaking away from the plaque. Group A streptococcus is the classic cause of erysipelas, but it may also be caused by other organisms. The face and lower extremities are common sites of involvement.*

Question 141

Where does the destruction of platelets occur in the pathogenesis of immune thrombocytopenia?

Answer 141

The spleen ## Footnote *The pathogenesis involves antibodies that bind platelets, and subsequent destruction of these complexes in the spleen. When there is life-threatening bleeding, the spleen may need to be removed. The spleen is the site of destruction of the platelets and by excising it, the platelets are spared. It is rarely needed, but can be a life-saving measure.*

Question 142

What kind of seizure is characterized by bried episodes of impaired consciousness, failure to respond to various stimuli during the episode, staring spells, automatisms, and post-ictal confusion?

Answer 142

Complex partial seizure ## Footnote *The electroencephalogram (EEG) pattern is usually normal or may show brief discharges. Unlike in absence seizures, hyperventilation during the EEG cannot simulate a complex partial seizure.*

Question 143

The following findings in a 3-4 month old patient is consistent with what diagnosis? 1. Hypoglycemia (hypoglycemic seizures may occur) 2. Lactic acidosis 3. Hyperuricemia 4. Hyperlipidemia 5. Doll-like face (fat cheeks) 6. Thin extremities 7. Short stature 8. Protuberant abdomen (due to enlarged liver and kidneys)

Answer 143

Von-Gierkes disease (Glucose-6-phosphatase deficiency) ## Footnote *This is type I glycogen storage disease. The spleen and heart are normal in this condition.*

Question 144

What is the first-line treatment for migraine headaches in children \< 12 years of age?

Answer 144

Acetaminophen, nonsteroidal anti-inflammatories, and supportive management ## Footnote *Triptans may be tried if these measures are not effective.*

Question 145

Cyanosis within the first few hours of life and a single loud second heart sound without a murmur are characteristics of what condition?

Answer 145

Transposition of the great vessels. ## Footnote *Because the aorta is located in front of the pulmonary artery, the S2 aortic component is better heard than is the soft S2 pulmonic valve component and is audible as a single S2. There is usually no murmur because the foramen ovale and ductus arteriosus have closed by the time cyanosis occurs. A patent foramen ovale or ductus arteriosus can maintain life after birth, but when they begin to close, decreased mixing of blood and poor oxygenation occur.*

Question 146

What is the best test for diagnosing Meckel's diverticulum?

Answer 146

Technetium-99m pertechnetate scan ## Footnote *In this test, the patient receives a tiny amount of intravenous technetium-99m, and a gamma camera highlights gastric mucosa and ectopic gastric tissue. Scintigraphy is noninvasive, highly sensitive and specific, and emits little radiation.*

Question 147

What should be suspected in a premature newborn with feeding intolerance, abdominal distension, and bloody stools?

Answer 147

Necrotizing enterocolitis ## Footnote *This is a similar presentation to malrotation with midgut volvulus . The two can be differentiated on abdominal x-ray. The hallmark x-ray finding in necrotizing enterocolitis is pneumatosis intestinalis. This is contrasted to other disorders such as milk protein-induced enterocolitis, which usually presents as blood-tinged stools in an otherwise healthy infant age 2-8 weeks after sensitization to milk protein. Clostridium difficile colitis rarely occurs in the first year of life and intussusception is rare in neonates.*

Question 148

What diagnosis should be considered for a newborn or young infant with failure to thrive, bilateral cataracts, jaundice and hypoglycemia?

Answer 148

Galactosemia ## Footnote *This is a metabolic disorder caused by galactose-1-phosphate uridyl transferase deficiency, thereby leading to elevated blood levelso of galactose. The typical presentation is vomiting, poor weight gain, jaundice, hepatomegaly, convulsions, and cataracts. Other common manifestations include aminoaciduria, hepatic cirrhosis, hypoglycemia, and mental retardation. Early diagnosis and treatment by elimination of galactose from the diet are mandatory.*

Question 149

The following findings are consistent with what diagnosis? 1. Cheilosis 2. Glossitis 3. Seborrheic dermatitis 4. Pharyngitis 5. Edema and/or erythema of the mouth

Answer 149

Riboflavin deficiency ## Footnote *Riboflavin = vitamin B₂*

Question 150

The following findings are consistent with what diagnosis? 1. Hearing loss 2. Recurrent fractures 3. Opalescent teeth 4. Blue sclerae

Answer 150

Osteogenesis imperfecta ## Footnote *This is a connective tissue disorder most commonly inherited from an autosomal dominant mutation of COL1A1. The disorder has a varying spectrum of severity, from mild (type-I), moderate (types III-IX), to fatal perinatal (type II) disease.*

Question 151

What typically causes pain that is worse at night and unrelated to activity, and appears as a sclerotic, cortical lesion on imaging with a central nidus of lucency?

Answer 151

Osteoid osteoma ## Footnote *Pain is quickly relieved by nonsteroidal anti-inflammatory medications.*

Question 152

What is the treatment for Lyme disease in children \< 8 years old?

Answer 152

Oral Amoxicillin ## Footnote *Doxycycline is contraindicated in children age \< 8 years old and pregnant women. It can slow bone growth in exposed fetuses and cause enamel hypoplasia and permanent teeth stains during tooth development in young children. Amoxicillin is as efficacious as oral doxycycline at treating Lyme disease. Doxycycline is used in adults because it is effective in treating potential coexisting Anaplasma phagocytophilum infection, which is also transmitted by the ixodes tick.*

Question 153

1. What enzyme is deficient in homocystinuria? 2. How is it inherited?

Answer 153

1. Cystathionine synthase 2. Autosomal recessive

Question 154

The following findings are consistent with what diagnosis? 1. Mental retardation 2. Seizures 3. Visual impairment 4. Port-wine stain over the territory of the trigeminal nerve

Answer 154

Sturge-Weber disease

Question 155

Autoantibodies against acetylcholine receptors causing early fatigability of the skeletal muscles is a feature of what diagnosis?

Answer 155

Myasthenia gravis

Question 156

Ash-leaf spots are most closely associated with what diagnosis?

Answer 156

Tuberous sclerosis

Question 157

The following signs/symptoms are characteristic of what diagnosis? 1. Fever 2. Headache 3. Focal neurologic deficits 4. Seizure Predisposing factors for this diagnosis include congenital heart disease and recurrent sinusitis.

Answer 157

Brain abscess *Siezures can be the initial manifestation in 25% of patients. This presentation differs from that of bacterial meningitis which presents with fever, headache, and lethargy but also presents with photophobia and nuchal rigidity.* *Brain imaging should be performed as the next step in diagnostic workup.*

Question 158

Tumor lysis syndrome is an oncologic emergency that results from tumor cell breakdown and the release of dangerous amounts of what 3 electrolytes into the circulation?

Answer 158

1. Potassium 2. Phosphate 3. Uric acid ## Footnote *This can occur spontaneously in patients with massive lymphoma or leukemia burden or more commonly after initiation of chemotherapy. Measurement of electrolytes is extremely important but does not identify the underlying malignancy.*

Question 159

The following findings on electrophoresis are consistent with what diagnosis? 1. Hemoglobin A: 0% 2. Hemoglobin S: 85-95% 3. Hemoglobin F: 5-15%

Answer 159

Sickle Cell Disease ## Footnote *This is a hemoglobinopathy with an autosomal recessive inheritance.*

Question 160

Painless hematochezia in a young toddler is most likely due to what?

Answer 160

Meckel's diverticulum

Question 161

The following findings are consistent with what diagnosis? 1. Thrombocytopenia 2. Eczema 3. Recurrent bacterial infections

Answer 161

Wiskott-Aldrich syndrome (WAS) ## Footnote *This is an X-linked disorder. Recurrent infections are usually due to streptococcus pneumoniae, neisseria meningitidis, and haemophilus influenzae. Eczema occurs in about half of all patients with WAS, and secondary skin infections are common. Despite these two features, however, thrombocytopenia is the most common manifestation of WAS, as over 90% of patients with WAS have significantly decreased platelet levels at the time of diagnosis. The thrombocytopenia is caused by decreased platelet production, and the few platelets that exist are typically quite small. The clinical effects of thrombocytopenia can vary from minor petechia or purpura to potentially life-threatening bleeding such as intracranial hemorrhage, hematemesis, or hematochezia. Platelet counts in patients with WAS are typically less than 50,000/mm3 and the mean platelet volume is also usually reduced, both features that are seen in this patient.*

Question 162

What is the first step in the management of a patient with gastrochisis?

Answer 162

Immediately wrap the exposed bowel in sterile saline dressing and plastic wrap ## Footnote *This should be done to minimize heat and fluid losses.*

Question 163

The following findings are suggestive of what diagnosis? 1. Recurrent respiratory infections 2. Steatorrhea 3. Failure to thrive

Answer 163

Cystic Fibrosis ## Footnote *Sweat chloride testing by quantitative pilocarpine iontophoresis is the gold standard for diagnosis.*

Question 164

What is the most common primary bone tumor in children and young adults?

Answer 164

Osteosarcoma ## Footnote *It typically involves the metaphyses of long bones. Physical examination typically shows a large and tender mass. Classic x-ray findings include "sunburst" periosteal reaction and Codman triangle.*

Question 165

The following characteristics are consistent with what developmental age? 1. Gross motor: Stands well, walks first steps independently, throws a ball 2. Fine motor: 2-finger pincer grasp 3. Language: Say first words (other than mama & dada) 4. Social/cognitive: Separation anxiety, follows 1-step command with gesture, imitates others

Answer 165

12 months

Question 166

The following findings are suggestive of what diagnosis? 1. Long narrow face 2. Prominent forehead and chin 3. Large ears 4. Macrocephaly

Answer 166

Fragile-X syndrome ## Footnote *These patients often have macroorchidism.*

Question 167

The following characteristics are consistent with what gestational age? 1. Gross motor: Walks up/down stairs with both feet on each step, jumps 2. Fine motor: Copies a circle, uses utensils 3. Language: 3-word sentences, speech 75% intelligible 4. Social/Cognitive: Knows age/gender, imaginative play

Answer 167

3 years

Question 168

What should you suspect in a child with sudden-onset abdominal pain, bloody diarrhea, and a triad of anemia, thrombocytopenia, and renal failure?

Answer 168

Hemolytic uremic syndrome ## Footnote *This is caused by a toxin released by E. Coli. The verotoxin invades and destroys the colonic epithelial lining, and produces a bloody diarrhea. Subsequent activation of the coagulation system and red cell hemolysis results in jaundice.*

Question 169

What throat infection is caused by enteroviruses, especially Coxsackie A virus and is characterized by high fever, ulcerative lesions on the palate, tonsils, and pharanx, and a sore throat that may result in a complete inability to swallow?

Answer 169

Herpangina ## Footnote *Sometimes the lesions appear on the palms and soles, in which case the infection is called hand-foot-mouth disease.*

Question 170

The following signs/symptoms are characteristic of what diagnosis? 1. Mental retardation 2. Blindness 3. Cherry-red macula 4. Weakness 5. Seizures

Answer 170

Tay-Sach's disease ## Footnote *This is a sphingolipidosis due to beta-hexosaminidase A deficiency.*

Question 171

What is the classic triad of congenital rubella syndrome?

Answer 171

1. Sensorineural deafness 2. Cardiac defects (I.E. patent ductus arteriosus) 3. Cataracts ## Footnote *Rubella infection in adults can be asymptomatic in 25-50% of patients or characterized by mild symptoms (I.E. low-grade fever, maculopapular rash). However, infection during pregnancy is dangerous due to high risk for transmission of the rubella virus from the mother's blood stream to the placenta and into fetal circulation. First-trimester infections are the most devastating, with potential outcomes such as spontaneous abortion and congenital rubella syndrome. Rubella immunization is contraindicated during pregnancy due to a theoretical risk for the live vaccine to cause fetal infection.*

Question 172

What differentiates generalized seizures from partial seizures?

Answer 172

Generalized seizures involve both hemispheres of the brain ## Footnote *Generalized seizures can have loss of consciousness, bilateral motor findings, and they can be convulsive or non-convulsive (absence seizures). Partial seizures can be further classified as simple partial, complex partial, and partial with secondary generalization, but all partial seizures arise from a discrete focus in the brain.*

Question 173

The concern with vesicoureteral reflux and recurrent UTIs is that there is a significant risk of what?

Answer 173

Renal scarring ## Footnote *Renal scarring secondary to reflux is a major cause of end-stage renal disease in children. Because the growing kidney is very prone to scarring, it is crucial that the diagnosis of reflux not be missed in young children.*

Question 174

What is the second most common tumor of the posterior fossa in children?

Answer 174

Medulloblastoma ## Footnote *Approximately 90% of cases arise from the vermis.*

Question 175

What are the confirmatory tests for systemic lupus erythematosus (SLE)?

Answer 175

Anti-Smith antibody test or anti-double stranded DNA antibody test

Question 176

Eczema herpeticum requires prompt treatment with what?

Answer 176

Acyclovir ## Footnote *This is a form of primary herpes simplex virus infection associated with atopic dermatitis. Numerous vesicles over the area of atopic dermatitis are typical. The infection can be life-threatening in infants and requires prompt treatment with acyclovir.*

Question 177

What is the treatment of choice for foreign body aspiration?

Answer 177

Rigid bronchoscopy ## Footnote *This presents with sudden-onset stridor, wheeze, coughing, or dyspnea.*

Question 178

What is the treatment for neonatal chlamydial conjunctivitis?

Answer 178

Oral erythromycin ## Footnote *Gonococcal conjunctivitis is treated with intravenous or intramuscular ceftriaxone or cefotaxime. Chemical conjunctivitis is treative with supportive measures.*

Question 179

What glomerulonephropathy is characterized by localized regions of mesangial sclerosis and basement membrane collapse, affecting only some glomeruli?

Answer 179

Focal segmental glomerulosclerosis ## Footnote *This is the most common cause of nephrotic syndrome in adults.*

Question 180

The following signs/symptoms are characteristic of what diagnosis? 1. Abdominal pain 2. Nausea 3. Vomiting 4. Vulvovaginitis (in women) 5. Nocturnal perianal pruritus

Answer 180

Enterobius vermicularis ## Footnote *This is the most common helminthic infection in the United States. It is most commonly seen in children aged 5-10. The adult parasite thrives in the human intestine, primarily in the cecum and appendix. At night, females migrate out through the rectum onto the perianal skin to deposit eggs, thereby resulting in the most common characteristic symptom, nocturnal perianal pruritus. Diagnosis is made by the "scotch tape test," which demonstrates the presence of Enterobius eggs. Albendazole or mebendazole are the first-line treatments.*

Question 181

What are the first-line drugs for the treatment of primary generalized tonic-clonic seizures or partial seizures with or without secondary generalization?

Answer 181

Phenytoin and Carbamazepine ## Footnote *Both drugs work by blocking the voltage-dependent sodium channels on the neuron's membrane. Phenytoin is also a second-line drug for the treatment of myoclonic and tonic-clonic seizures.*

Question 182

What is the initial step in the management of children with speech delay?

Answer 182

Audiology evaluation

Question 183

Why doesnt beta thalassemia cause symptoms in a newborn until around 6 months of age?

Answer 183

Newborns have mostly fetal hemoglobin ## Footnote *Fetal hemoglobin is comprised of alpha and gamma globin chains. After 6 months of age, symptoms of hemolytic anemia emerge as gamma globin chains are replaced with beta for the production of adult hemoglobin.*

Question 184

Persistent stridor that worsens in supin position and improves in prone position is characteristic of what diagnosis?

Answer 184

Laryngomalacia ## Footnote *This is most noticeable at age 4-8 months and is caused by increased laxity of the supraglottic structures that results in collapse during the inspiratory phase. It typically presents with stridor that is loudest in the supine position and improves when the infant is held upright or prone.*

Question 185

The following characteristics are consistent with what diagnosis? 1. Gross motor: balances & hops on 1 foot 2. Fine motor: Copies a square 3. Language: Identifies colors, speech 100% intelligible 4. Social/Cognitive: Cooperative play

Answer 185

4 years

Question 186

What is the most common type of spinocerebellar ataxias?

Answer 186

Friedreich ataxia ## Footnote *The most common causes of death are cardiomyopathy and respiratory complications.*

Question 187

The following findings are characteristic of what diagnosis? 1. Fever 2. Malaise 3. Painful enlargement of the parotid glands 4. Orchitis in males

Answer 187

Mumps ## Footnote *Treatment for mumps is supportive, with application of cold compresses to the parotid area or testes. Other common complications of mumps are aseptic meningitis and encephalitis.*

Question 188

What is the treatment for Rocky Mountain Spotted Fever?

Answer 188

Doxycycline for 5-7 days ## Footnote *This presents as a rash on the palms and soles, headache, and gastrointestinal symptoms.*

Question 189

What differentiates congenital cytomegalovirus from congenital rubella?

Answer 189

In congenital cytomegalovirus infection, the deafness is typically unilateral, blindness is usually due to chorioretinitis, and the heart is unaffected

Question 190

The following findings are characteristic of what diagnosis? 1. Recurrent sinusitis 2. Bronchiectasis 3. Dextrocardia

Answer 190

Kartegener's syndrome (Primary ciliary dyskinesia) ## Footnote *This syndrome is an autosomal recessive disorder due to dysmotile cilia. The aberrant production or attachment of dynein arms can frequently be verified on electron microscopy, and results in impaired cilial function, poor clearance of secretions, and consequent chronic secondary infections.*

Question 191

What presents in an infantwith pruritus and skin lesions typically distributed symmetrically over the face, scalp, chest, and extensor surfaces of the extremities, but spares the diaper region?

Answer 191

Atopic dermatitis in infancy ## Footnote *Atopic dermatitis is the result of decreased skin barrier function due to improper synthesis of components of the epidermal cornified cell envelope. This allows allergens ready access to the deeper levels of the epidermis where they may generate the immune response characteristic of atopic dermatitis. Treatment is with improvement of skin barrier function through the use of mild cleansers and thick, bland emolients in addition to mild topical anti-inflammatory ointments.*

Question 192

What causes hyperbilirubinemia and feeding intolerance (vomiting, diarrhea) in a newborn?

Answer 192

Galactosemia

Question 193

What is differentiates an atrial septal defect (ASD) from a ventricular septal defect (VSD) on physical exam?

Answer 193

An ASD is associated with a fixed split S2 ## Footnote *Both can have systolic ejection murmurs (Left upper sternal border for ASD and left lower sternal border for VSD) and diastolic murmurs.*

Question 194

The following findings in a newborn are consistent with what diagnosis? 1. Decreased moro reflex 2. Decreased biceps reflex 3. Intact grasp reflex

Answer 194

Erb-Duchenne palsy ## Footnote *This presents as "waiter's tip" with an extended elbow, pronated forearm, and flexed wrist & fingers.*

Question 195

How do epidural hematomas present on Computed Tomography (CT) of the head?

Answer 195

Biconvex mass ## Footnote *Epidural hematomas are often associated with a lucid interval followed by rapid neurological deterioration. They are caused by injury to meningeal blood vessels, and do not usually cross suture lines because of the better dural attachment at the sutures.*

Question 196

What presents in the first 3 months of life with pallor and poor feeding in a patient with a normocytic or macrocytic anemia and reticulocytopenia?

Answer 196

Diamond-Blackfan anemia (DBA) ## Footnote *This is a congenital pure red cell aplasia. White blood cell and platelet counts are normal*

Question 197

Auer rods are specific for what diagnosis?

Answer 197

Acute myeloid leukemia (AML)

Question 198

What is the most common cause of congenital hypothyroidism in the United States?

Answer 198

Thyroid dysgenesis ## Footnote *Thyroid dysgenesis (I.E. aplasia, hypoplasia, or an ectopic gland) accounts for 85% of cases in the United States.*

Question 199

What kind of hypersensitivity reaction is anaphylaxis (as in response to a bee sting)?

Answer 199

Type I hypersensitivity reaction ## Footnote *This is IgE-mediated hypersensitivity. Patients with severe allergies should carry a self-injectable epinephrine pen at all times. In addition, patients should be referred to an allergist for venom immunotherapy which can reduce repeat bee sting anaphylaxis risk from 30% to*

Question 200

The following findings are consistent with what diagnosis? 1. Cafe-au-lait spots 2. Macrocephaly 3. Feeding problems 4. Short stature 5. Learning disabilities

Answer 200

Neurofibromatosis 1 ## Footnote *Patients may later develop fibromas, neurofibromas or different tumors.*

Question 201

The following findings are consistent with what diagnosis? 1. Congenital unilateral cavernous hemangioma along the trigeminal nerve distribution 2. Radiographic evidence of intra-cranial calcifications that resemble a tramline

Answer 201

Sturge-Weber Syndrome ## Footnote *This is a neurocutaneous syndrome that can include focal or generalized seizures, mental retardation, and a port wine stain or nevus flammeus along the territory of the trigeminal nerve, which represents a congenital unilateral cavernous hemangioma. Other pertinent findings are hemianopia, hemiparesis, hemisensory disturbance, and ipsilateral glaucoma. Skull x-rays taken after the age of 2 years reveal gyriform intacranial calcifications that resemble a tramline. Treatment is aimed at controlling the seizures and reducing intraocular pressure. Argon laser therapy is successful in removing skin lesions.*

Question 202

The following characteristics are consistent with what developmental age? 1. Gross motor: Walks up/down stairs with both feet on each step, jumps 2. Fine motor: Builds 6-cube tower, copies a line 3. Language: 50+ word vocabulary, 2-word phrases 4. Social/Cognitive: Follows 2-step command, parallel play, begins toilet-training

Answer 202

2 years

Question 203

Which coagulation factors rely on vitamin K as a cofactor?

Answer 203

Factors II, VII, IX, and X as well as protein S and Protein C ## Footnote *Vitamin K is an important cofactor for the liver enzyme gamma-glutamyl carboxylase which adds carboxyl groups to the glutamate residues of several coagulation factors. These extra carboxyl groups increase the affinity of these proteins for the phospholipid on the surface of the platelets.*

Question 204

What are the 2 first-line treatments for Enterobius vermicularis infection?

Answer 204

Albendazole or mebendazole ## Footnote *Pyrantel pamoate is a 2nd line treatments as it is associated with more side effects and less efficacy than albendazole or mebendazole.*

Question 205

What disorder is usually caused by a microdeletion of chromosome 22q11?

Answer 205

DiGeorge syndrome

Question 206

The following characteristics are consistent with what gestational age? 1. Gross motor: Skips, walks backward 2. Fine motor: Copies a triangle, ties shoelace, independent dressing/bathing, prints letters 3. Language: Counts to 10, 5-word sentences 4. Social/Cognitive: Has friends, completes toilet training

Answer 206

5 years

Question 207

What is the treatment of an epidural hematoma with features suggestive of deteriorating neurological status or increased inctracranial pressure?

Answer 207

Emergent craniotomy

Question 208

CD4+ lymphocyte destruction is the hallmark finding in what disease?

Answer 208

Human immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS)

Question 209

What is the most significant risk factor for intraventricular hemorrhage in a newborn?

Answer 209

Prematurity ## Footnote *It is also common in low birth weight infants.*

Question 210

What kind of seizure is characterized by brief (typically a few seconds) periods of impaired consciousness that may also present with automatisms, but doesn't not have a post-ictal state?

Answer 210

Typical absence seizure ## Footnote *Electroencephalogram (EEG) reveals a generalized 3Hz spike-and-wave pattern on a normal background. An atypical absence seizure lasts longer and shows slow spike-and-wave activity with a frequency less than 2.5Hz.*

Question 211

What are the drugs of choice for congenital long QT syndrome?

Answer 211

Beta-blockers (I.E. propranolol) ## Footnote *If the patient is asymptomatic or does not have a clearly documented syncope, beta blocker alone is sufficient. If the patients is symptomatic or has a documented episode of syncope, the treatment will be beta-blocker plus a Dual-chamber (DDD) pacemaker.*

Question 212

The following findings are consistent with what diagnosis? 1. Distant heart sounds 2. Hypotension 3. Distended jugular veins

Answer 212

Pericardial effusion ## Footnote *Definitive treatment is achieved by pericardiocentesis or pericardiectomy*

Question 213

What is the first-line modality in diagnosing intussusception?

Answer 213

Ultrasound ## Footnote *A positive "target sign" should prompt reduction with air or water-soluble contrast enema.*

Question 214

The following signs/symptoms are characteristic of what diagnosis? 1. Mental retardation 2. Fair complexion 3. Blue eyes 4. Eczema 5. Musty body odor

Answer 214

Phenylketonuria ## Footnote *This is an inborn error of metabolism of phenylalanine, wherein phenylalanine hydroxylase is the deficient enzyme. This deficiency results in the build-up of phenylalanine an its metabolites (phenyl ketones) in the blood and body fluids.*

Question 215

What is a common cause of unconjugated hyperbilirubinemia in the second week of life?

Answer 215

Breast-milk jaundice ## Footnote *The unconjugated bilirubin levels may rise as high as 10-30 mg/dL. Levels drop rapidly as soon as breastfeeding is stopped., and the infant is given milk formula for 1-2 days. After 2-3 days the breastfeeding can be resumed, and usually there is no return of the hyperbilirubinemia. Although it is a benign condition in some instances, phototherapy may be indicated.*

Question 216

What is the definition of direct hyperbilirubinemia in a neonate?

Answer 216

Conjugated bilirubin \>2 mg/dL or \>20% of total bilirubin

Question 217

The following signs/symptoms are characteristic of what diagnosis? 1. Palpable purpura 2. Hematuria 3. Abdominal pain 4. Arthralgias 5. Scrotal swelling in males

Answer 217

Henoch-Schonlein purpura (HSP) ## Footnote *This is an immune-mediated vasculitis that is most common in children age*

Question 218

What benign neonatal rash is characterized by blanching erythematous papules and/or pustules that resolves spontaneously within 2 weeks after birth?

Answer 218

Erythema toxicum neonatorum ## Footnote *"toxicum" is a misnomer as the rash is benign and evanescent. It is common in full-term neonates. The rash can change appearance and can occur on any part of the body (sparing the palms and soles) in the first 2 weeks of life. The etiology is unkown. Parents should be reassured that treatment is unnecessary as the rash resolves spontaneously without sequelae.*

Question 219

What typically presents with virilization of female infants, salt-wasting, and increased 17-hydroxyprogesterone levels?

Answer 219

21-hydroxylase deficiency *This is the most common cause (90% of cases) of congenital adrenal hyperplasia.* *21-hydroxylase deficiency prevents progesterone and 17-hydroxyprogesterone from being converted into aldosterone and cortisol, respectively. This leads to a mineralocorticoid deficit (hypotension, hyponatremia, hyperkalemia), while the resulting buildup of 17-hydroxyprogesterone is instead shunted toward adrenal androgen synthesis (virilization of females).*

Question 220

What condition leads to deficient formation of mature B and T lymphocytes due to toxic accumulation of adenosine?

Answer 220

Adenosine deaminase deficiency ## Footnote *This is an autosomal recessive form of severe combined immunodeficiency that leads to deficient formation of mature B and T lymphocytes due to toxic accumulation of adenosine. Most patients present with life-threatening infections, failure to thrive, and persistent diarrhea. Laboratory studies show severe lymphopenia.*

Question 221

What is the appropriate management of a simple febrile seizure?

Answer 221

Reassurance ## Footnote *Simple febrile seizures do not require any workup. Patients can be discharged home from the emergency department with reassurance about a good prognosis.*

Question 222

What is characterized as a diffuse, sometimes ecchymotic, swelling of the scalp of a newborn that may extend across the midline and across suture lines?

Answer 222

Caput succedaneum ## Footnote *It usually involves the portion of the head presenting during vertex delivery.*

Question 223

The first dose of measles, mumps, rubella, and varicella vaccines is typically administered at what age?

Answer 223

Around 1 year of age ## Footnote *Live attenuated vaccines can be safely administered to immunocompetent infants regardless of gestational age. All vaccines should be administered according to chronological rather than gestational age in preterm infants.*

Question 224

What is the most common cause of bacterial meningitis in children and young adults?

Answer 224

Meningococcal meningitis ## Footnote *It typically presents with fever, headache, neck stiffness, altered mental status, and a petechial or purpuric rash.*

Question 225

What disease is characterized as a malignant spindle cell neoplasm found mostly in patients 30-60 years of age that usually presents as a painful mass, with a radiological picture of an osteolytic lesion whose margins can be well-defined or ragged and moth-eaten?

Answer 225

Fibrosarcoma

Question 226

What condition is often associated with false positive Rapid Plasma Reagin (RPR) test results?

Answer 226

Systemic Lupus Erythematosus (SLE) ## Footnote *The confirmatory tests for SLE are anti-Smith antibody test and anti-double stranded DNA (dsDNA) test.*

Question 227

What chromosomal deletion is responsible for Cri-du-chat syndrome?

Answer 227

5p deletion ## Footnote *It presents as microcephaly, hypotonia, short stature, and a cat-like cry.*

Question 228

What decreases the need for intubation in patients with croup and should always be tried before any invasive procedure?

Answer 228

Racemic epinephrine

Question 229

For pertussis prevention, all close contacts should be given what?

Answer 229

Erythromycin for 14 days *This is regardless of age, immunizations, or symptoms. Pertussis is a highly contagious disease despite immunization (despite immunization, over 75% of household contacts will develop some symptoms of pertussis if exposed)*.

Question 230

What disorder is characterized by a defect in tyrosine kinase in B cells?

Answer 230

Bruton's agammaglobulinemia

Question 231

The following findings are consistent with what diagnosis? 1. Fever for _\>_ 5 days 2. Mucous membrane changes 3. Extremity changes 4. Nonexudative conjunctivitis 5. Cervical lymph node _\>_ 1.5cm 6. Polymorphous rash

Answer 231

Kawasaki Disease

Question 232

Cat bites should be treated prophylactically with a 5-day course of what antibiotic(s)?

Answer 232

Amoxicillin/Clavulanate ## Footnote *Cat bites are concerning because of risk of infection with pasteurella multocida. This infection develops quickly and is associated with conderable pain, erythema, and swelling. Localized cellulitis can develop subacutely, and in some cases, systemic effects (fever, lymphadenopathy) may arise. Prophylactic treatment is thus recommended for such cases. For treatment of minor cat bite wounds, amoxicillin/clavulanate for 5 days is recommended.*

Question 233

What is the best test to confirm the diagnosis of muscular dystrophy?

Answer 233

Muscle biopsy ## Footnote *This can confirm the diagnosis in most cases. The gold standard is genetic studies, which is required in atypical cases.*

Question 234

The following findings are consistent with what diagnosis? 1. Congenital marrow failure 2. Poor growth 3. Morphologic abnormalities 4. Macrocytic anemia

Answer 234

Fanconi anemia ## Footnote *This is an autosomal recessive or X-linked disorder associated with clinical manifestations of aplastic anemia and progressive bone marrow failure, short stature, microcephaly, abnormal thumbs, hypogonadism, hypopigmented/hyperpigmented areas, cafe au lait spots, and large freckles, strabismus, low-set ears, and middle ear abnormalities (e.g. hemorrhage, incomplete development, chronic infections, deafness)*

Question 235

What is the inheritance pattern of Homocystinuria?

Answer 235

Autosomal recessive ## Footnote *It results from a deficiency in cystathionine synthase.*

Question 236

What is the treatment for a clavicular fracture in a newborn?

Answer 236

Reassurance and gentle handling ## Footnote *Most clavicular fractures heal rapidly without complications.*

Question 237

What is the most common pediatric renal malignancy?

Answer 237

Wilms tumor ## Footnote *It should be suspected in a toddler with a firm, smooth, unilateral abdominal mass and hematuria.*

Question 238

Erb-Duchenne palsy results from damage to which nerves?

Answer 238

C5 and C6 ## Footnote *This the most common type of brachial plexus injury, and is described as the "waiter's tip" posture. The affected arm of a neonate may have decreased or absent moro reflexes, but grasp reflex should remain intact.*

Question 239

The following characteristics are consistent with what developmental age? 1. Gross motor: Sits momentarily propped on hands (unsupported by 7 months) 2. Fine motor: Transfers objects hand to hand, raking grasp 3. Language: Responds to name, babbles 4. Social/cognitive: Stranger anxiety

Answer 239

6 months

Question 240

What primary bone tumor typically involves the metaphyses of long bones in children and young adults?

Answer 240

Osteosarcoma ## Footnote *Boys between ages 13 and 16 years of age are at higher risk. In children, the tumor occurs most frequently at the metaphyses of long bones such as the distal femur, proximal tibia, and proximal humerus.*

Question 241

Acute hepatitis B infection in children often leads to the development of renal complication?

Answer 241

Membranous glomerulonephritis ## Footnote *This association is particularly seen in those patients positive for HBeAg, which may be secondary to the deposition of HBeAg itself or its corresponding antibody in the glomeruli. Hepatitis B-associated membranous glomerulonephritis is more common in children than adults.*

Question 242

What developmental disorder is characterized by a forward slip of vertebrae that usually manifests in preadolescent children?

Answer 242

Spondylolisthesis ## Footnote *It usually occurs with a forward slip of L5 over S1. In the typical clinical scenario, back pain, neurologic dysfunction (I.E. urinary incontinence), and a palpable "step-off" at the lumbosacral area are present if the disease is severe.*

Question 243

The following characteristics are suggestive of what diagnosis? 1. Temporal wasting 2. Thin cheeks 3. Upper lip in the shape of an inverted V 4. Emaciated extremities 5. Proximal muscle weakness

Answer 243

Myotonic muscular dystrophy (Steinert disease) ## Footnote *Additional abnormalities of the endocrine, immunologic, and nervous systems can occur. Endocrine manifestations include diabetes mellitus, testicular atrophy, frontal baldness, and hypothyroidism.*

Question 244

Patients with complement deficiencies are at increased risk of what?

Answer 244

1. Encapsulated bacterial infections (Strep pneumo, H. Influenza, and N. Meningitidis) 2. Autoimmune conditions

Question 245

Exhaled nasal nitric oxide is a screening test for what condition?

Answer 245

Primary ciliary dyskinesia (Kartagener's syndrome)

Question 246

What presents at birth with hepatosplenomegaly, cutaneous lesions, jaundice, anemia, and rhinorrhea?

Answer 246

Congenital syphilis ## Footnote *Radiographs show metaphyseal dystrophy and periostitis. Late congenital manifestations (presenting after 2 years of age) include frontal bossing, high arched palate, hutchinson teeth, interstitial keratitis, saddle nose, and perioral fissures.*

Question 247

What is caused by repetitive contraction of the extensor muscles of the forearm?

Answer 247

Lateral epicondylitis (Tennis elbow) ## Footnote *Tenderness is elicited over the lateral epicondyle, and pain is felt with passive wrist flexion and resisted wrist extension.*

Question 248

What diagnosis fits the following description? A benign tumor that consists of dilated lymphatic spaces lined by endothelium that most commonly occurs on the neck, and on physical exam is lobulated, compressible, and will usually transilluminate.

Answer 248

Cystic Hygroma (lymphangioma)

Question 249

What typically causes edema in Turner Syndrome?

Answer 249

Abnormal development of the lymphatic system ## Footnote *This results in lymphedema. Edema that is due to lymphedema is generally nonpitting on physical exam as opposed to the pitting edema seen with congestive heart failure, or nephrotic syndrome.*

Question 250

What is the definitive treatment for aplastic anemia in Fanconi Anemia?

Answer 250

Hematopoietic stem cell transplantation

Question 251

What should be suspected in any newborn with Down syndrome who fails to pass meconium within 48 hours after birth, especially in the setting of Down Syndrome?

Answer 251

Hirschprung disease ## Footnote *The presentation is consistent with complete bowel obstruction (e.g. poor feeding, abdominal distension, absent air in the rectum)*

Question 252

What condition is characterized by a unique susceptibility to opportunistic infections and neutropenia, with high IgM levels?

Answer 252

Hyper-IgM syndrome

Question 253

In an infant, a soft click, leg-length discrepancy, or asymmetric inguinal skin folds requires furthur workup with what?

Answer 253

1. Infants 2 weeks - 6 months: _Hip ultrasound_ 2. Infant 4 months - 6 months: _Hip X-ray_ ## Footnote *The treatment of choice for age*

Question 254

What is the most common pathogen responsible for causing recurrent sinopulmonary infections in a patient with cystic fibrosis who is \> 20 years old?

Answer 254

Pseudomonas aeruginosa ## Footnote *Amikacin, ceftazidime, and ciprofloxacin are all appropriate for empiric treatment of pseudomonas.*

Question 255

What differentiates Asperger syndrome from Autism?

Answer 255

Patients with Asperger syndrome are usually more socially aware and communicative and have normal language development ## Footnote *Both may have stereotypical movements and self-injurious behavior.*

Question 256

The following findings in a child age 5 to 10 years is consistent with what diagnosis? 1. Symmetrical proximal muscle weakness 2. Cutaneous findings (I.E. Gottron's papules, heliotrope rash, malar rash) 3. Arthralgias 4. Dysphagia

Answer 256

Juvenile dermatomyositis ## Footnote *This is a rare autoimmune myositis. The onset of the juvenile form is generally between 5 and 10 years of age.*

Question 257

What is the inheritance pattern of Congenital Contractural arachnodactyly (CCA)?

Answer 257

Autosomal dominant ## Footnote *It presents with tall stature, arachnodactyly, and multiple contractures involving large joints. Marfan's patients do not have joint contractures. Furthermore, ocular and cardiovascular symptoms are not present in CCA.*

Question 258

What is the most common pathogen responsible for recurrent sinopulmonary infections in a cystic fibrosis patient from birth to age ~20 years?

Answer 258

Staphylococcus aureus ## Footnote *Intravenous vancomycin is the drug of choice for severe pneumonia in this setting.*

Question 259

What is the most common cause of nephrotic syndrome in adults in the United States?

Answer 259

Focal Segmental Glomerulosclerosis ## Footnote *This is characterized by localized regions of mesangial sclerosis and basement membrane collapse. As suggested by the name, not all glomeruli are affected in this disease. Minimal change disease is the most common form of idiopathic nephrotic syndrome in children.*

Question 260

What diagnosis should be suspected in children with acute onset of fever and joint pain in the setting of elevated white blood cell count, erythrocyte sedimentation rate, and C-reactive protein?

Answer 260

Septic arthritis ## Footnote *The appropriate initial management consists of arthrocentesis, blood and synovial fluid cultures, and empiric antibiotic therapy.*

Question 261

What are the 3 most common cardiovascular abnormalities in Turner syndrome?

Answer 261

1. Bicuspid aortic valve (20-30%) 2. Coarctation of the aorta (3-10%) 3. Aortic root dilation (with an increased risk of aortic dissection)

Question 262

What is the treatment for homocystinuria?

Answer 262

High doses of vitamin B₆ (pyridoxine) ## Footnote *Restriction of methionine along with supplementation of cysteine is used for patients not responsive to vitamin B₆ therapy.*

Question 263

What is the third most common cause of neonatal sepsis?

Answer 263

Listeria Monocytogenes ## Footnote *This is transmitted from mother to newborn. Pregnant women with listeriosis have nonspecific flulike symptoms such as fever, body aches, and fatigue prior to delivery.*

Question 264

A blood smear showing occasional red blood cells with single, round, blue inclusions on Wright stain is suggestive of what?

Answer 264

Functional asplenia ## Footnote *These blue inclusions are nuclear remnants called Howell-Jolly bodies that are normally removed by the spleen. Their presence strongly suggests physical or functional hyposplenism.*

Question 265

What is the treatment for neonatal gonococcal conjunctivitis?

Answer 265

Intravenous or intramuscular ceftriaxone or cefotaxime ## Footnote *Neonatal chlamydial conjunctivitis is treated with oral erythromycin.*

Question 266

1. What is the second most common muscular dystrophy? 2. How is it inherited?

Answer 266

Myotonic muscular dystrophy (Steinert disease) Autosomal dominant *The pathology is distinct in that all types of muscles (smooth, striated, and cardiac) are involved. Myotonia is defined as delayed muscle relaxation and the classic example is the inability to release the hand after a handshake. It may present as progressive weakness and delayed muscle relaxation in a patient with temporal wasting, thin cheeks, emaciated extremities, atrophy of the thenar/hypothenar eminences, an upper lip in the shape of an inverted V, and testicular atrophy.*

Question 267

Any male adolescent who presents with epistaxis, a localized mass, and a bony erosion on the back of the nose has what diagnosis until proven otherwise?

Answer 267

Angiofibroma ## Footnote *This is a benign growth, but is capable of eroding and locally invading. In some cases, no treatment is necessary. Treatment is required if the angiofibroma is enlarging, obstructing the airway, or causing chronic nosebleeds. recurrence of the tumor after surgical resection is common.*

Question 268

At what age is Wilms tumor usually diagnosed?

Answer 268

Age 2-5 years ## Footnote *It affects a single kidney (less than 10% of patients have bilateral renal involvement). The most common presentation is an asymptomatic abdominal mass that is found incidentally by a caretaker or physician. Some patients have abdominal pain, hypertension, hematuria, and fever.*

Question 269

What are the 2 most common causes of neonatal sepsis?

Answer 269

Group B strep and Escherichia coli

Question 270

What it the first-line treatment for Bordetella pertussis infection?

Answer 270

Macrolide antibiotics ## Footnote *This includes azithromycin, erythromycin, and clarithromycin.*

Question 271

The sugar water test is done for the diagnosis of what cause of anemia?

Answer 271

Paroxysmal nocturnal hemoglobinuria (PNH) ## Footnote *This disorder is characterized by an absence of glycosylphosphatidylinositol (GPI) on the surface of red blood cells. GPI normally anchors cell-protective proteins to the surface of red blood cells and without it, red cells are particularly vulnerable to lysis.*

Question 272

A previously asymptomatic male infant with recurrent pneumonia and otitis media after 6-9 months of age is the typical patient with what diagnosis?

Answer 272

Bruton's agammaglobulinemia ## Footnote *This is also known as X-linked agammaglobulinemia. It is a recessive disorder characterized by a defect in tyrosine kinase in B cells. The maternal IgG antibodies are responsible for keeping the infant free from infections in the first 6-9 months of life. The diagnosis is confirmed by decreased serum concentrations of IgG, IgA, IgM, and IgE, along with absent or markedly decreased B cells on the smear.*

Question 273

Histologic evidence of extensive fatty vacuolization of the liver without inflammation is suggestive of what diagnosis?

Answer 273

Reye syndrome

Question 274

How do children with congenital deficiency of alpha-1-protease usually present?

Answer 274

With signs of respiratory and liver failure

Question 275

The following signs/symptoms are the classic triad of what diagnosis? 1. Uremia 2. Thrombocytopenia 3. Hemolytic anemia

Answer 275

Hemolytic uremic syndrome ## Footnote *Investigations include Complete blood count (CBC), platelet count, blood smear, urinalysis, BUN and creatinine. Treatment is generally supportive, and involves plasmapheresis, dialysis if necessary, and steroids. Antibiotics are not indicated.*

Question 276

What diagnosis should be suspected when a newborn chokes and coughs during the first feeding?

Answer 276

Esophageal atresia with tracheoesophageal fistula ## Footnote *Attempts at naso- or oro-gastric tube insertion will fail and x-ray will show the tube in the proximal esophageal pouch.*

Question 277

The following findings are consistent with what diagnosis? 1. Endocrine syndrome 2. Intracranial hypertension 3. Parinaud's sign (paralysis of the vertical gaze) 4. Collier's sign (retraction of the eyelid)

Answer 277

Pinealoma ## Footnote *This develops in the dorsal aspect of the midbrain.*

Question 278

The presence of a cystic calcified parasellar lesion on magnetic resonance imaging is almost diagnostic of what?

Answer 278

Craniopharyngioma ## Footnote *A young boy with symptoms of increased intracranial pressure, bitemporal hemianopsia, and a calcified lesion above the sella has a craniopharyngioma until proven otherwise. Craniopharyngiomas are more common in boys, whereas pituitary adenomas are more common in women.*

Question 279

What type of hypersensitivity occurs when an allergen binds and cross-links two IgE molecules attached to the mast cell?

Answer 279

IgE-mediated (type I) hypersensitivity ## Footnote *Atopy, urticaria, and anaphylaxis are examples of this form of hypersensitivity.*

Question 280

What kind of seizure has the following characteristics? 1. Loss of consciousness 2. Tonic-clonic activity 3. Seizure activity limited to a part of the brain

Answer 280

Partial seizure with secondary generalization

Question 281

What disease typically presents as a male infant who is initially asymptomatic until 6-9 months of age, after which he begins to experience recurrent pyogenic (s. pneumoniae and H. influenzae) infections?

Answer 281

Bruton's (X-linked) agammaglobulinemia ## Footnote *The diagnosis is confirmed by decreased serum concentrations of IgG, IgA, IgM, and IgE, along with absent or markedly decreased B cells on smear.*

Question 282

What is the standard treatment for amylopia (lazy eye with decrease in the visual acuity of one or both eyes)?

Answer 282

Occlusion of the normal eye

Question 283

Ascending demyelinating polyradiculoneuropathy that progresses in a stepwise fashion from the legs to other muscles of the body is a feature of what diagnosis?

Answer 283

Guillain Barre Syndrome

Question 284

What is the most specific sign of eardrum inflammation?

Answer 284

Bulging of the tympanic membrane on pneumatic insufflation

Question 285

DiGeorge syndrome is marked by dysmorphogenesis of which pharyngeal pouch(es)?

Answer 285

3rd and 4th pharyngeal pouches ## Footnote *Affected patients develop hypocalcemia from parathyroid hypoplasia and defective T-cell function from thymic hypoplasia. Fungal and viral infections are common.*

Question 286

What condition is characterized by bony overgrowth that can form in the outer ear and lead to hearing loss?

Answer 286

Otosclerosis

Question 287

The following characteristics in a patient who is less than 3 years old is suggestive of what diagnosis? 1. Impairment in social interactions and communication 2. Delayed language development 3. Stereotypical behaviors

Answer 287

Autism ## Footnote *This is also called pervasive developmental disorder. Lack of peer relationships and nonverbal social cues, delayed social smile, repetitive activities and preference for sameness are also very commonly seen in these kids.*

Question 288

What diagnosis should be suspected in a child under the age of 5 years who presents with proximal muscle weakness, Gower's sign, diminished reflexes, and pseudohypertrophy of the calf muscles?

Answer 288

Duchenne muscular dystrophy ## Footnote *Serum CK and aldolase levels will be elevated even before the appearance of any clinical signs of disease. Genetic testing or muscle biopsy can confirm the diagnosis.*

Question 289

The following characteristics are consistent with what developmental age? 1. Gross motor: Lifts head/chest in prone position 2. Fine motor: Hands unfisted 50% of the time, tracks past midline 3. Laguage: Alerts to voice/sound, coos 4. Social/cognitive: Social smile, recognizes parents

Answer 289

2 Months

Question 290

The immunologic findings of what disease include low IgM levels, high IgA and IgE levels, poor antibody responses to polysaccharide antigens, and moderately reduced number of T cells and platelets?

Answer 290

Wiskott-Aldrich syndrome (WAS) ## Footnote *The classic presentation involves a young boy with eczema, thrombocytopenia, and recurrent infections with encapsulated germs.*

Question 291

What differentiates Rubella (German measles) from Measles?

Answer 291

By contrast, Rubella is relatively mild and shorter in duration. The Rubella rash spreads cephalocaudally but does not darken as does measles. The fever is also lower and no Koplik spots are seen.

Question 292

What is the leading risk factor for cerebral palsy?

Answer 292

Prematurity (\< 32 weeks gestation) ## Footnote *Cerebral Palsy is a group of syndromes characterized by nonprogressive motor dysfunction. Affected patients have uncoordinated and limited voluntary movements.*

Question 293

The following findings are consistent with what diagnosis? 1. Ambiguous genitalia in girls 2. Fluid And salt retention 3. Hypertension 4. Decreased cortisol 5. Decreased aldosterone 6. Increased testosterone

Answer 293

11Beta-hydroxylase deficiency *Increased levels of 11-deoxycorticosterone and 11-deoxycortisol will be present. This condition accounts for* *).*

Question 294

What disease is characterized as a common vascular benign tumor that affects women more frequently than men and usually presents in the fourth decade of life with the triad of severe intermittent pain, tenderness, and sensitivity to touch, most often occurring subungually (70% of the time), and less commonly occurring in the palm and wrist.

Answer 294

Glomus tumor

Question 295

The following signs/symptoms are characteristic of what diagnosis? 1. Sensorineural deafness 2. Developmental delay 3. Blindness 4. Jaundice 5. Hepatosplenomegaly 6. Petechiae

Answer 295

Congenital Cytomegalovirus ## Footnote *This is the most common congenital viral infection.*

Question 296

What is the most common cause of congenital adrenal hyperplasia?

Answer 296

Deficiency of 21-hydroxylase ## Footnote *It typically presents with virilization of female infants, salt-wasting, and increased 17-hydroxyprogesterone levels. 21-hydroxylase deficiency prevents progesterone and 17-hydroxyprogesterone from being converted into aldosterone and cortisol, respectively. This leads to a mineralocorticoid deficit (hypotension, hyponatremia, hyperkalemia), while the resulting buildup of 17-hydroxyprogesterone is instead shunted toward adrenal androgen synthesis (virilization of females).*

Question 297

The following findings are consistent with what diagnosis? 1. All patients are phenotypically female 2. Fluid and salt restriction 3. Hypertension 4. Decreased cortisol 5. Decreased testosterone 6. Increased mineralocorticoid 7. Increased corticosterone (weak glucocorticoid)

Answer 297

17alpha-hydroxylase deficiency ## Footnote *Male patients usually appear phenotypically female and are raised as girls. Patients typically present around puberty with hypertension, hypokalemia, and hypogonadism.*

Question 298

What diagnosis should be suspected when a child who recently recovered from a diarrheal illness presents with acute renal failure, microangiopathic hemolytic anemia, fever, thrombocytopenia, and characteristic peripheral smear finding of schistocytes?

Answer 298

Hemolytic Uremic Syndrome (HUS) ## Footnote *This is usually preceded by an acute diarrheal illness due to the pathogens Escherichia coli serotype 0157:H7, Shigella, Salmonella, Yersinia, and Campylobacter species.*

Question 299

60-80% of all cases of Reye syndrome are preceded by an upper respiratory infection with one of which two viruses?

Answer 299

Influenza virus or varicella virus ## Footnote *Reye syndrome is seen exclusively in children younger than 15 years of age. Treatment with salicylates significantly increases the likelihood of developing Reye syndrome.*

Question 300

The following signs/symptoms are characteristic of what diagnosis? 1. Fever 2. Fatigue 3. Exudative pharyngitis 4. Posterior cervical lymphadenopathy 5. A polymorphous, maculopapular rash following amoxicillin treatment

Answer 300

Infectious mononucleosis caused by Epstein-Barr virus (EBV) ## Footnote *The rash is not considered to be a true drug allergy, and patients can receive the same antibiotic in the future.*

Question 301

Burr cells are spiculated red blood cells of similar size and with with regularly spaced projections. They are seen most commonly in what condition?

Answer 301

Uremia ## Footnote *These can be seen as an artifact of preparation.*

Question 302

What is the most common predisposing factor for orbital cellulitis?

Answer 302

Bacterial sinusitis ## Footnote *This is the most common predisposing factor for orbital cellulitis due to the prevalence of this disease as well as the proximity of the sinuses to the orbital space and the valveless orbital venous system. Symptoms of orbital cellulitis include proptosis, ophthalmoplegia, and diplopia.*

Question 303

What is the treatment of choice for local impetigo?

Answer 303

Topical mupirocin or oral erythromycin ## Footnote *Penicillin is no longer used for the treatment of impetigo, as Staph aureus is almost universally resistant (\>99%) to penicillin. Oral cephalexin, dicloxacillin, and ampicillin are alternative drugs in severe cases.*

Question 304

What is the most appropriate antibiotic therapy for bacterial meningitis in an infant or child \>28 days old?

Answer 304

Intravenous ceftriaxone + Vancomycin ## Footnote *The most common bacterial causes in children \> 1 month old are streptococcus pneumoniae and Neisseria meningitidis. Vancomycin is used because of resistant strains of sterptococcus pneumoniae.*

Question 305

What is the mechanism of infant botulinism?

Answer 305

Clostridium botulinum organism in the intestinal tract ## Footnote *In the infantile form of botulism, the causative organism gains entry through the food and produces the toxin in the intestinal tract, which subsequently triggers the symptoms. It is a protease that blocks acetylcholine release. Infants typically present between two weeks and nine months with constipation and poor feeding. This is followed by progressive hypotonia, weakness, loss of deep tendon reflexes, cranial nerve abnormalities (impaired gag reflex), and respiratory difficulties. Signs of autonomic dysfunction such as hypotension and neurogenic bladder can occur early in the course of the disease. In the adult form of botulinism, the toxin is ingested and produces symptoms.*

Question 306

What is the treatment for respiratory distress syndrome in a newborn premature infant?

Answer 306

Continuous positive air pressure ventilation ## Footnote *Chest x-ray would typically show fine reticular granularity of the lungs.*

Question 307

The following signs/symptoms are characteristic of what diagnosis? 1. Fever 2. Fatigue 3. Pharyngitis 4. Cervical lymphadenopathy 5. Splenomegaly

Answer 307

Infectious mononucleosis

Question 308

What is the appropriate management for a newborn born to a mother with active hepatitis B infection?

Answer 308

Passive immunization at birth with hepatitis B immune globulin (HBIG) followed by active immunization with recombinant HBV vaccine

Question 309

The screening of aminolevulinic acid and porphobilinogen in the blood is used to diagnoses what?

Answer 309

Porphyrias ## Footnote *This is a group of inherited disorders associated with neurological signs, photosensitivity and hyperpigmentation.*

Question 310

Bilateral acoustic neuromas and cataracts are features of what condition?

Answer 310

Neurofibromatosis 2

Question 311

During which phase of sleep do night terrors occur?

Answer 311

Non-Rapid Eye Movement (non-REM) sleep ## Footnote *They are characterized by fear, crying or screaming, decreased level of consciousness, and amnesia of the event. In contrast, nightmares occur during REM sleep.*

Question 312

The following signs/symptoms are characteristic of what diagnosis? 1. Respiratory stridor that improves with neck extension but not with corticosteroids, racemic epinephrine, or bronchodilators 2. Esophageal symptoms (dysphagia)

Answer 312

Vascular rings ## Footnote *These result from abnormal development of the aortic arch and can encircle both the trachea and esophagus. Infants with vascular rings typically present before age 1 year with respiratory or esophageal symptoms. Diagnosis can be confirmed with barium contrast esophagogram, bronchoscopy, CT, or MRI. The only definitive treatment is surgical intervention.*

Question 313

What is the diagnostic method of choice for ingested foreign body?

Answer 313

Felxible endoscopy ## Footnote *This is diagnostic and can be therapeutic by directly visualizing and manipulating the foreign body. Rigid endoscopy has a higher risk of esophageal abrasion and perforation and is usually reserved for impacted sharp objects in the proximal esophagus.*

Question 314

Bluish-white lesions on buccal mucosa are pathognomonic for what diagnosis?

Answer 314

Measles ## Footnote *This presents with a prodome of cough, coryza, and conjunctivitis. The classic reddish-brown rash appear on days 3-5 on the face and spreads downward to the rest of the body. The rash persists for a week, coalesces, and darkens to a reddish-brown color. Measles (Rubeola) is an extremely contagious disease that is spread by infected droplets from respiratory secretions. The virus can remain airborne for several hours, and unvaccinated patients can contract it by entering a room that an infected person has exited.*

Question 315

What are the 3 most common manifestations of polycythemia in newborns?

Answer 315

1. Respiratory distress 2. Poor feeding 3. Neurologic manifestations (lethargy, irritability, jitteriness, and seizures) ## Footnote *Polycythemia is defined as a central venous hematocrit level \>65%.*

Question 316

What is the treatment of choice for developmental dysplasia of the hip in an infant \< 6 months old?

Answer 316

Pavlik hip harness

Question 317

Until proven otherwise, Leukocoria is considered an indication of what diagnosis?

Answer 317

Retinoblastoma ## Footnote *Leukocoria = white reflex on ophthalmoscopic exam*

Question 318

By the age of 3 years, a child's vocabulary has usually increased to how many words?

Answer 318

1000 words ## Footnote *75% of the child's speech can be understood by a stranger.*

Question 319

The following findings are consistent with what diagnosis? 1. Ambiguous genitalia in girls 2. Salt wasting (vomiting, hypotension, decreased sodium, increased potassium) 3. Decreased cortisol 4. Decreased aldosterone 5. Increased testosterone

Answer 319

21-hydroxylase deficiency *Increased levels of 17-hydroxyprogesterone will also be present.*

Question 320

Cafe-au-lait macules are most closely associated with what diagnosis?

Answer 320

Neurofibromatosis

Question 321

What disease is characterized as a highly malignant tumor that typically occurs in white males in their first or second decade of life, is found in the lower extremity more than the upper extremity, is very aggressive and metastasizes early to the lungs and lymph nodes, and classically presents as pain and swelling for weeks or months?

Answer 321

Ewing's Sarcoma ## Footnote *Patients may initially be diagnosed with osteomyelitis, based on the misleading presentation of intermittent fevers, leukocytosis, anemia, and an increased ESR. Nevertheless, Ewing's sarcoma can be distinctly characterized radiologically with its lamellated appearance or "onion skin" periosteal reaction. The lesion is usually lytic, central, and accompanied by endosteal scalloping. The "onion-skin" appearance is often followed with a "moth-eaten" or mottled appearance and extension into soft tissue. The treatment includes surgery, radiation, and multi-drug chemotherapy.*

Question 322

Respiratory Syncytial virus infection in childhood may increase the risk of developing what later in life?

Answer 322

Asthma

Question 323

What is the antibiotic treatment of choice in treating bacterial rhinosinusitis in children?

Answer 323

Amoxicillin-clavulanic acid ## Footnote *This is the treatment of choice due to increasing beta-lactamase resistance. Streptococcus pneumoniae and nontypeable haemophilus influenzae are the most common causes of acute bacterial rhinosinusitis.*

Question 324

What is the treatment for Bruton's (X-linked) agammaglobulinemia?

Answer 324

Regular intravenous infusions of immune globin ## Footnote *This disease is due to a defect in Bruton's tyrosine kinase, a signaling molecule expressed in B cells at all stages of development.*

Question 325

What differentiates iron deficiency anemia from thalassemia?

Answer 325

Red cell distribution width (RDW) Iron deficiency anemia is characterized by an elevated RDW, which is typically \>20%. Normal values of 12-14% are seen in thalassemia.

Question 326

All immunocompromised hosts who are asymptomatic and nonimmune should receive what post-exposure prophylaxis?

Answer 326

Varicella zoster immune globulin ## Footnote *All immunocompetent patients who are asymptomatic and nonimmune should recieve the varicella vaccine for post-exposure prophylaxis.*

Question 327

What are the diagnostic criteria for Attention-deficit hyperactivity disorder (ADHD)?

Answer 327

Inattentive or hyperactive-impulsive symptoms that cause impairment in two different settings for more than 6 months in a child less than 7 years old

Question 328

What has a similar presentation to Bruton's agammaglobulinemia but with less severe symptoms that manifest at a later age (15-35 years old)?

Answer 328

Common variable immunodeficiency (CVID) ## Footnote *The serum concentrations of IgG, IgA, IgM, and IgE may also be decreased, but there is no absence or decrease in the number of circulating B cells.*

Question 329

What is the appropriate treatment for most cases of acute, unilateral cervical adenitis in children?

Answer 329

Incision & drainage and clindamycin ## Footnote *Unilateral cervical adenitis in children is typically caused by streptococcal or staphylococcal infection.*

Question 330

The following findings are consistent with what diagnosis? 1. Nephropathy 2. Normal light microscopy and immunoflorescence 3. Electron microscopy showing diffuse effacement of foot processes of podocytes

Answer 330

Minimal Change Disease

Question 331

An elevated WBC with the following cellular characteristics is consistent with what diagnosis? 1. Blast cells with condensed nuclear chromatin, small nucleoli, and scant agranular cytoplasm 2. Strongly positive periodic acid Schiff (PAS) reaction 3. No Auer rods

Answer 331

Acute lymphoblastic leukemia (ALL) ## Footnote *The presence of more than 25% lymphoblasts in the bone marrow is diagnostic. Lymphoblasts lack peroxidase positive granules but often contain cytoplasmic aggregates of periodic acid Schiff (PAS) positive material. Immunostaining for terminal deoxynucleotidyltransferase (TdT) is positive in more than 95% of patients. TdT is only expressed by pre-B and pre-T lymphoblasts.*

Question 332

What condition is associated with an accumulation of fluid in the inner ear that leads to hearing loss, vertigo, and tinnitus?

Answer 332

Meniere's disease

Question 333

The following findings are consistent with what diagnosis? 1. Irritability 2. Depression 3. Dermatitis 4. Stomatitis (inflammation of the mouth)

Answer 333

Pyridoxine deficiency ## Footnote *Pyridoxine = vitamin B₆*

Question 334

The following signs/symptoms are characteristic of what diagnosis? 1. Marfanoid features 2. Mental retardation 3. Thromboembolic events 4. Downward dislocation of the lens

Answer 334

Homocystinuria ## Footnote *This is an autosomal recessive disease caused by cystathionine synthase deficiency. Treatment mainly involves administration of high doses of vitamin B6.*

Question 335

Anterior knee pain localized to the patella that worsens upon descending steps or hills is characteristic of what diagnosis?

Answer 335

Patellofemoral stress syndrome (patellofemoral pain syndrome) ## Footnote *This is an overuse injury commonly seen in runners.*

Question 336

The following findings in a newborn are consistent with what diagnosis? 1. Decreased moro reflex 2. Intact biceps reflex 3. Intact grasp reflex

Answer 336

Fractured humerus *Upper-arm crepitus/bony irregularity* *may also be present. The decreased moro reflex is due to pain on the affected side.*

Question 337

Craniopharyngiomas are derived from epithelial remnants of what?

Answer 337

Rathke's pouch ## Footnote *It is not a true pituitary tumor, and is characterized by nests of squamous cells in a loose stroma, resembling the appearance of embryonic tooth bud enamel.*

Question 338

The following findings are consistent with what diagnosis? 1. Precocious puberty 2. Pigmentation (cafe-au-lait spots) 3. Polyostotic fibrous dysplasia

Answer 338

McCune-Albright syndrome ## Footnote *This is a rare condition characterized by precocious puberty, cafe-au-lait spots and multiple bone defects (polyostotic fibrous dysplasia). It is responsible for 5% of the cases of female precocious puberty, and may be associated with other endocrine disorders, such as hyperthyroidism, prolactin or growth hormone secreting pituitary adenomas, and adrenal hypercortisolism. McCune-Albright syndrome is sporadic and has been recently attributed to a defect in the G-protein cAMP-kinase function in the affected tissue, thereby resulting in autonomous activity of that tissue.*

Question 339

The following findings are suggestive of what diagnosis? 1. Small palpebral fissures 2. Smooth philtrum 3. Thin vermilion border (Thin upper lip) 4. Microcephaly

Answer 339

Fetal alcohol syndrome

Question 340

The following findings are characteristic of what diagnosis? 1. Eczema 2. Thrombocytopenia 3. Hypogammaglobulinemia

Answer 340

Wiskott-Aldrich syndrome ## Footnote *This is a rare x-linked recessive disease.*

Question 341

Croup is most commonly caused by what?

Answer 341

Parainfluenza virus type I ## Footnote *Patients typically present with fever, stridor, and barking cough. Corticosteriods or nebulized epinephrine may be used in treatment.*

Question 342

What should be suspected in any patient with Down syndrome who presents with upper motor neuron findings?

Answer 342

Atlantoaxial instability ## Footnote *This is a malformation seen in 10-15% of patients with Down syndrome, and most commonly occurs due to excessive laxity in the posterior transverse ligament, which causes increased mobility between the atlas (C1) and the axis (C2). Only 1-2% of Down syndrome patients with atlantoaxial instability are symptomatic. Symptoms usually progress over several weeks and result from compression of the spinal cord.*

Question 343

What usually presents in a 4-8 week old infant as non-bilious projectile vomiting which gradually becomes more frequent and forceful?

Answer 343

Pyloric stenosis ## Footnote *Significant physical findings are a palpable abdominal mass and visible peristaltic waves in the upper abdomen.*

Question 344

What is the only infant factor that is an absolute contraindication to breastfeeding?

Answer 344

Galactosemia