SEM 2 - PEDIA

Question 1

An infant who sits with only minimal support, attempts to attain a toy beyond reach, and rolls over from supine to the prone position, but does not have a pincer grasp, is at a developmental level of:
a. 2 months
b. 9 months
c. 4 months
d. 6 months

Answer 1

d. 6 months

🧠 High-Yield Rationale:

A 6-month-old typically rolls from supine to prone, sits with minimal support, and may attempt to reach for objects beyond reach. Pincer grasp, however, develops around 9 months, so its absence is normal here.

🚫 Why not the others:

❌ a. 2 months – At this age, the infant has poor head control, and can’t roll over or sit.

❌ b. 9 months – Would have a pincer grasp and pull to stand, which this infant does not do.

❌ c. 4 months – Can roll from prone to supine, but not yet supine to prone or sit independently.

Question 2

Of the following physical findings in a newborn, which would most reliably indicate that the infant was mature (40 weeks gestation)?
a. Head circumference over 34 cm
b. Sole of foot covered with creases
c. Presence of ear cartilage
d. Thick and silky scalp hair

Answer 2

a. Head circumference over 34 cm

Question 3

A 2-year-old boy presents with a fever of 39.4°C that has lasted for the past 5 days. You also note bilateral conjunctivitis, dry red fissured lips, a maculopapular rash over the extremities and trunk, and swelling of the hands and feet. Based on these findings, you make the diagnosis of Kawasaki’s disease. What is the most appropriate initial therapy?
a. Corticosteroids
b. Antibiotics
c. Electrolyte replacement
d. Aspirin and intravenous immunoglobulin (IVIG)

Answer 3

d. Aspirin and intravenous immunoglobulin (IVIG)

🧠 High-Yield Rationale:

Standard initial therapy for Kawasaki disease is IVIG to reduce coronary artery aneurysms and aspirin for its anti-inflammatory and antiplatelet effects.

🚫 Why not the others:

❌ a. Corticosteroids – May be used in refractory cases, not first-line.

❌ b. Antibiotics – Not useful; it’s not an infectious etiology.

❌ c. Electrolyte replacement – Not relevant unless dehydration is present.

Question 4

A full-term newborn at 30 hours of age presents with jaundice. Her unconjugated bilirubin level is 15 mg/dL, and her hematocrit is 48. Which of the following is the most likely cause?
a. Autoimmune hepatitis
b. Physiologic jaundice
c. Polycythemia
d. ABO incompatibility

Answer 4

b. Physiologic jaundice

🧠 Rationale & High-Yield Discussion:

👶 Neonatal Presentation:

🕒 At 30 hours, jaundice in a term infant with normal Hct (48%) and unconjugated hyperbilirubinemia is classic for physiologic jaundice.

📊 Physiologic vs. Pathologic:

🌿 Physiologic jaundice typically appears after 24 hours, peaks by day 3–5, and resolves in 1–2 weeks.

❌ Pathologic jaundice (like ABO incompatibility or polycythemia) occurs within the first 24 hours, or involves rapid rises in bilirubin or high levels (>15 early on) with other abnormal labs.

🚫 Why not the others:

❌ a. Autoimmune hepatitis – Not a neonatal condition.

❌ c. Polycythemia – Would show Hct >65%, not 48%.

❌ d. ABO incompatibility – More likely if bilirubin rises before 24 hours and is rapidly progressive; usually presents with anemia or reticulocytosis.

Question 5

Asthma and allergic rhinitis have many characteristics in common. All of the following statements are true of both EXCEPT:
a. Avoidance of precipitating factors is the best treatment
b. Inhaled corticosteroids are effective treatment
c. Obstruction of the airway is an important effect
d. They may be life-threatening

Answer 5

d. They may be life-threatening

🧠 Rationale & High-Yield Discussion:

✨ Shared Features of Asthma and Allergic Rhinitis:

🔹 a. ✅ Avoidance of precipitating factors helps manage both.

🔹 b. ✅ Inhaled corticosteroids (for asthma) and intranasal corticosteroids (for rhinitis) are effective.

🔹 c. ✅ Airway obstruction is present—bronchial in asthma, nasal in rhinitis.

⚠️ Critical Exception:

🚫 d. ❌ They may be life-threatening → False for allergic rhinitis.

⚠️ Asthma can be life-threatening in severe attacks (e.g., status asthmaticus).

😌 Allergic Rhinitis is chronic and uncomfortable, but not fatal.

Question 6

Characteristics of childhood migraine typically include each of the following, EXCEPT:
a. Duration of headache more than 24 hours
b. Strong family history of migraine
c. Bifrontal headaches
d. Paroxysmal headaches

Answer 6

a. Duration of headache more than 24 hours

🧠 Rationale & High-Yield Discussion:

🧒 Childhood migraines are shorter in duration than adult migraines—usually 1 to 72 hours, but commonly <4 hours.

👨‍👩‍👧 Strong family history is common.

🤕 Pain is often bifrontal or bitemporal, unlike the classic unilateral adult migraine.

⚡ Paroxysmal onset and termination is characteristic.

🚫 Why not the others:

✅ b. Strong family history of migraine – Common due to genetic predisposition.

✅ c. Bifrontal headaches – Typical in children.

✅ d. Paroxysmal headaches – True feature; sudden onset.

Question 7

Peripheral pulmonic stenosis, atrial septal defect, ventricular septal defect, chorioretinitis, hepatosplenomegaly, jaundice, and “blueberry muffin spots” are the clinical manifestations typically associated with which congenital infection?
a. Toxoplasmosis
b. Herpes simplex virus
c. Rubella
d. Cytomegalovirus

Answer 7

c. Rubella

🧠 Rationale & High-Yield Discussion:

🌸 Congenital Rubella Syndrome (CRS) classically presents with:

💔 Congenital heart defects: most commonly PDA, but PPS, ASD, and VSD are also seen.

👁️ Chorioretinitis and cataracts

👂 Sensorineural deafness

🩸 “Blueberry muffin” rash from dermal extramedullary hematopoiesis

🍋 Hepatosplenomegaly, jaundice, and growth retardation

🚫 Why not the others:

❌ a. Toxoplasmosis – Triad: chorioretinitis, hydrocephalus, diffuse intracranial calcifications.

❌ b. Herpes simplex virus (HSV) – Skin, eye, mouth lesions; encephalitis; no cardiac defects.

❌ d. Cytomegalovirus (CMV) – Also causes blueberry muffin rash, chorioretinitis, and periventricular calcifications, but does NOT commonly cause congenital heart defects like PPS or VSD.

Question 8

One of the following statements is NOT TRUE of hereditary spherocytosis:
a. It manifests as anemia and hyperbilirubinemia
b. It is an enzymatic defect
c. It may present with splenomegaly in children
d. It is usually transmitted as an autosomal dominant disorder and less frequently as an autosomal recessive disorder

Answer 8

b. It is an enzymatic defect

🧠 Rationale & High-Yield Discussion:

⚠️ Hereditary spherocytosis is a membrane defect, not enzymatic.

Specifically involves proteins like spectrin or ankyrin.

Presents with:

🩸 Anemia, jaundice, hyperbilirubinemia

🏥 Splenomegaly

🧬 Autosomal dominant inheritance in most cases

🚫 Why not the others:

✅ a. Anemia and hyperbilirubinemia – True.

✅ c. Splenomegaly in children – Common.

✅ d. Autosomal dominant inheritance – 75% of cases.

Question 9

In patients with disseminated intravascular coagulation (DIC), what coagulation factor is consumed?
a. Factor IX
b. Factor XII
c. Factor XIII
d. Fibrinogen

Answer 9

d. Fibrinogen

🧠 Rationale & High-Yield Discussion:

💥 DIC (Disseminated Intravascular Coagulation) causes widespread activation of clotting, consuming:

🧵 Fibrinogen

🧬 Platelets

🧪 Coagulation factors → bleeding risk increases

🚫 Why not the others:

❌ a. Factor IX – Part of intrinsic pathway, not a hallmark of DIC consumption.

❌ b. Factor XII – Not commonly measured/consumed in DIC.

❌ c. Factor XIII – Stabilizes fibrin clot but not prominently depleted in DIC.

Question 10

Pertussis is highly communicable:
a. In all stages of the disease
b. During the convalescence stage
c. During the catarrhal stage
d. During the paroxysmal cough stage

Answer 10

c. During the catarrhal stage

🧠 Rationale & High-Yield Discussion:

🤧 The catarrhal stage resembles a common cold and is the most contagious phase.

❗ Early treatment here prevents transmission.

🗣️ The paroxysmal stage has classic coughing fits, but less contagious.

🚫 Why not the others:

❌ a. All stages – Incorrect; peak transmission is early.

❌ b. Convalescence stage – Recovery phase, not contagious.

❌ d. Paroxysmal stage – Loud cough, but lower infectivity.

Question 11

Which of the following vitamins or minerals needs to be supplemented in infants that are exclusively breast-fed?
a. Iron
b. Vitamin C
c. Vitamin D
d. Folic acid

Answer 11

c. Vitamin D

🧠 Rationale & High-Yield Discussion:

🌞 Breast milk is low in vitamin D, so supplementation (400 IU/day) is recommended starting within the first few days of life in exclusively breastfed infants to prevent rickets.

🚫 Why not the others:

❌ a. Iron – Supplemented starting at 4–6 months if complementary foods aren’t rich in iron.

❌ b. Vitamin C – Breast milk contains adequate vitamin C.

❌ d. Folic acid – Sufficient in breast milk; no supplementation needed.

Question 12

A short 16-year-old girl presents with delayed puberty, a webbed neck, a shield chest, and a cardiac murmur. What is the most appropriate screening test to evaluate for the associated complication of the condition?
a. Ophthalmologic evaluation
b. Chromosomal analysis
c. 2D Echocardiography
d. Head CT scan

Answer 12

b. Chromosomal analysis

🧠 Rationale & High-Yield Discussion:

🧬 Classic signs point to Turner syndrome (45,X).

Features: short stature, delayed puberty, webbed neck, shield chest, left-sided heart defects (e.g., coarctation of the aorta).

Karyotyping confirms diagnosis.

🚫 Why not the others:

❌ a. Ophthalmologic eval – Not a primary concern here.

❌ c. 2D Echo – Useful after diagnosis to evaluate for cardiac defects.

❌ d. Head CT – No indication for CNS imaging in this presentation.

Question 13

The most common presentation of retinoblastoma is:
a. Leukocoria
b. Proptosis
c. Pupillary irregularity
d. Hyphema

Answer 13

a. Leukocoria

🧠 Rationale & High-Yield Discussion:

👁️ Leukocoria (white pupillary reflex) is the most common and earliest presenting sign.

Retinoblastoma = most common intraocular malignancy of childhood.

Prompt evaluation needed to prevent vision loss or metastasis.

🚫 Why not the others:

❌ b. Proptosis – Seen in orbital tumors, not classic for retinoblastoma.

❌ c. Pupillary irregularity – Not a hallmark feature.

❌ d. Hyphema – Blood in anterior chamber, not characteristic of retinoblastoma.

Question 14

The Reed-Sternberg cell is the cardinal histologic feature of:
a. Ewing’s Sarcoma
b. Neuroblastoma
c. Retinoblastoma
d. Hodgkin’s lymphoma

Answer 14

d. Hodgkin’s lymphoma

🧠 Rationale & High-Yield Discussion:

🔬 Reed-Sternberg cells are giant binucleated cells (owl’s eye appearance) pathognomonic for Hodgkin lymphoma.

Important for diagnosis and subtype classification.

🚫 Why not the others:

❌ a. Ewing’s Sarcoma – Small round blue cell tumor; no RS cells.

❌ b. Neuroblastoma – Rosette-forming tumor; no RS cells.

❌ c. Retinoblastoma – Contains Flexner-Wintersteiner rosettes.

Question 15

A 15-month-old female presents with a mass noted on the chest x-ray in the superior mediastinal region associated with left-sided miosis and ipsilateral ptosis. The most likely diagnosis is:
a. Wilm’s tumor
b. Neuroblastoma
c. Acute leukemia
d. Rhabdomyosarcoma

Answer 15

b. Neuroblastoma

🧠 Rationale & High-Yield Discussion:

🧠 This is Horner syndrome (ptosis, miosis ± anhidrosis), caused by cervical sympathetic chain involvement.

🧒 In a child with a superior mediastinal mass, the most likely tumor is neuroblastoma, especially if coming from the sympathetic ganglia.

🚫 Why not the others:

❌ a. Wilms tumor – Arises from kidney, presents as abdominal mass.

❌ c. Acute leukemia – Presents with systemic signs, not mediastinal mass + Horner syndrome.

❌ d. Rhabdomyosarcoma – Can be mediastinal but less commonly associated with Horner syndrome.

Question 16

Roentgenologically, the lungs may be hypovascular if associated with:
a. Aortic stenosis
b. Mitral stenosis
c. Pulmonic stenosis
d. Tricuspid valve

Answer 16

c. Pulmonic stenosis

🧠 Rationale & High-Yield Discussion:

🫁 Pulmonic stenosis limits blood flow to the lungs, leading to hypovascular lung fields on chest x-ray due to decreased pulmonary perfusion.

🚫 Why not the others:

❌ a. Aortic stenosis – Affects systemic circulation, not pulmonary vasculature.

❌ b. Mitral stenosis – Causes pulmonary congestion, not hypovascularity.

❌ d. Tricuspid valve – May lead to right-sided heart failure but doesn’t directly cause lung hypovascularity.

Question 17

Which valve is commonly affected in rheumatic carditis?
a. Aortic valve
b. Mitral valve
c. Pulmonic valve
d. Tricuspid valve

Answer 17

b. Mitral valve

🧠 Rationale & High-Yield Discussion:

❤️ Mitral valve is the most commonly affected valve in rheumatic fever, especially in children and young adults.

Lesions include valvulitis, leading to mitral regurgitation or stenosis.

🚫 Why not the others:

❌ a. Aortic valve – Can be involved, but usually secondarily.

❌ c. Pulmonic valve – Rarely affected.

❌ d. Tricuspid valve – Affected more in IV drug users or congenital conditions.

Question 18

After dental extraction, transient bacteremia most likely reveals:
a. E. coli
b. Pneumococcus
c. Staph. Aureus
d. Streptococcus viridans

Answer 18

d. Streptococcus viridans

🧠 Rationale & High-Yield Discussion:

🦷 Dental procedures often introduce Streptococcus viridans into the bloodstream — part of normal oral flora.

This is the classic organism associated with subacute bacterial endocarditis.

🚫 Why not the others:

❌ a. E. coli – GI tract flora, not oral.

❌ b. Pneumococcus – Causes pneumonia, otitis; not typical after dental work.

❌ c. Staph. aureus – Common in skin flora, not dominant in oral cavity.

Question 19

A “boot-shaped” appearance of the heart on a plain chest radiograph is characteristic of:
a. Single ventricle
b. Transposition of the great arteries
c. Tetralogy of Fallot
d. Total anomalous pulmonary venous connection

Answer 19

c. Tetralogy of Fallot

🧠 Rationale & High-Yield Discussion:

👢 “Boot-shaped heart” = Tetralogy of Fallot, due to RV hypertrophy and upturned apex.

Also seen: decreased pulmonary vascularity, consistent with RV outflow obstruction.

🚫 Why not the others:

❌ a. Single ventricle – Enlarged, globular heart but not boot-shaped.

❌ b. TGA – “Egg-on-a-string” appearance.

❌ d. TAPVC – Snowman or figure-of-8 shadow in supracardiac type.

Question 20

Characteristics seen on chest x-ray in staphylococcal pneumonia include all of the following, EXCEPT:
a. Hilar adenopathy
b. Pneumothorax
c. Pleural effusion
d. Rapid progression

Answer 20

a. Hilar adenopathy

🧠 Rationale & High-Yield Discussion:

🔥 Staph pneumonia is aggressive, with:

⚡ Rapid progression

💨 Pneumothorax from necrotic lung tissue

💧 Pleural effusion

🚫 But hilar adenopathy is not typical — more common in TB or lymphoma.

🚫 Why not the others:

✅ b. Pneumothorax – Can occur due to lung necrosis and rupture.

✅ c. Pleural effusion – Common due to severe inflammation.

✅ d. Rapid progression – Hallmark of Staph aureus pneumonia in children.

Question 21

The characteristic roentgenographic findings of infantile respiratory distress syndrome are:
a. Diffuse reticulogranular changes and air bronchograms
b. Bilateral patchy densities and pneumothorax
c. Diffuse aeration and cardiomegaly
d. Lobar atelectasis and interstitial edema

Answer 21

a. Diffuse reticulogranular changes and air bronchograms

🧠 Rationale & High-Yield Discussion:

👶 Infantile Respiratory Distress Syndrome (IRDS), also called Hyaline Membrane Disease, occurs due to surfactant deficiency in premature infants.

🫁 Classic X-ray shows:

🌫️ Diffuse reticulogranular (“ground-glass”) appearance

🌬️ Air bronchograms (air-filled bronchi visible against collapsed alveoli)

🚫 Why not the others:

❌ b. Bilateral patchy densities and pneumothorax – Suggest Staph pneumonia or aspiration, not IRDS.

❌ c. Diffuse aeration and cardiomegaly – Seen in conditions like transient tachypnea or cardiac issues, not IRDS.

❌ d. Lobar atelectasis and interstitial edema – Typical of bronchiolitis or congestive heart failure, not IRDS.

Question 22

A 13-year-old girl has scaling papules and plaques. When she injures her skin, new lesions develop at the site of trauma. What is the most likely diagnosis?
a. Psoriasis
b. Contact dermatitis
c. Pityriasis rosea
d. Tinea corporis

Answer 22

a. Psoriasis

🧠 Rationale & High-Yield Discussion:

🩹 The Koebner phenomenon (lesions appearing at sites of trauma) is a hallmark of psoriasis.

🧼 Also presents with scaling, erythematous plaques, often on extensor surfaces.

🚫 Why not the others:

❌ b. Contact dermatitis – Related to allergen exposure; not trauma-induced.

❌ c. Pityriasis rosea – “Herald patch” and Christmas tree pattern; not trauma-related.

❌ d. Tinea corporis – Fungal, ring-shaped lesion with central clearing; no Koebner phenomenon.

Question 23

The pathophysiology of infantile respiratory distress syndrome in the premature infant appears to involve:
a. Decreased production of pulmonary surfactant
b. Increased production of pulmonary surfactant
c. Decreased metabolism of pulmonary surfactant
d. Increased metabolism of pulmonary surfactant

Answer 23

a. Decreased production of pulmonary surfactant

🧠 Rationale & High-Yield Discussion:

🧬 Surfactant reduces surface tension in alveoli; produced by Type II pneumocytes.

👶 Premature infants (<34 weeks) often have insufficient surfactant, leading to alveolar collapse, poor gas exchange, and hypoxia.

🚫 Why not the others:

❌ b. Increased production – The problem is deficiency, not excess.

❌ c. Decreased metabolism – Irrelevant; surfactant is underproduced, not poorly broken down.

❌ d. Increased metabolism – Not the primary issue in IRDS.

Question 24

A 3-year-old child drinks some kerosene that had been left in a glass. After the first swallow, she cries and drops the glass. She is most likely to develop:
a. Hepatitis
b. Chemical pneumonitis
c. Peripheral neuritis
d. Aplastic anemia

Answer 24

b. Chemical pneumonitis

🧠 Rationale & High-Yield Discussion:

🛢️ Hydrocarbon (kerosene) ingestion is dangerous due to aspiration, leading to chemical pneumonitis.

🫁 Even small amounts can inflame lung tissue and impair oxygen exchange.

🚫 Why not the others:

❌ a. Hepatitis – Not associated with kerosene.

❌ c. Peripheral neuritis – Seen with toxins like lead or isoniazid.

❌ d. Aplastic anemia – Seen in benzene toxicity, not kerosene.

Question 25

You are awakened in the night by your 2-year-old son, who has developed noisy breathing on inspiration, marked retractions of the chest wall, flaring of the nostrils, and a barking cough. He has a mild upper respiratory infection for 2 days. The most likely diagnosis is: a. Asthma b. Viral croup c. Epiglottitis d. Bronchiolitis

Answer 25

b. Viral croup 🧠 Rationale & High-Yield Discussion: 🐶 Barking cough, stridor, and preceding URI = classic for viral croup (laryngotracheobronchitis). 🦠 Most commonly caused by parainfluenza virus. 🛏️ Worse at night, responds to cool air, corticosteroids, or nebulized epinephrine. 🚫 Why not the others: ❌ a. Asthma – Expiratory wheezing, not barking cough or stridor. ❌ c. Epiglottitis – Sudden onset, drooling, toxic appearance; NOT barking cough. ❌ d. Bronchiolitis – Caused by RSV; wheezing and lower airway symptoms, not stridor.

Question 26

Acute bronchiolitis is common in the first 2 years of life and results from inflammatory obstruction of the small airways. The most common causative agent is: a. Adenovirus b. Parainfluenza c. Mycoplasma d. Respiratory syncytial virus

Answer 26

d. Respiratory syncytial virus 🧠 Rationale & High-Yield Discussion: 👶 RSV (Respiratory Syncytial Virus) is the most common cause of bronchiolitis in infants under 2 years. 🫁 Causes inflammation and mucus plugging of bronchioles → wheezing, cough, respiratory distress. 🚫 Why not the others: ❌ a. Adenovirus – Can cause severe pneumonia, but not the most common cause of bronchiolitis. ❌ b. Parainfluenza – Causes croup, not bronchiolitis. ❌ c. Mycoplasma – Causes atypical pneumonia in older children/adolescents.

Question 27

Prenatal exposure to this agent may cause lower birth length, weight, head circumference, and decreased IQ: a. Pollution b. Malnutrition c. Cigarette smoke d. Psychological problems

Answer 27

c. Cigarette smoke 🧠 Rationale & High-Yield Discussion: 🚬 Maternal smoking during pregnancy is associated with: 🧠 Lower IQ ⚖️ Decreased birth weight, length, and head circumference 🫁 Increased risk of SIDS, asthma, and behavioral problems 🚫 Why not the others: ❌ a. Pollution – May contribute to complications but less clearly linked. ❌ b. Malnutrition – Affects growth, but smoking has a stronger evidence base for IQ. ❌ d. Psychological problems – May affect parenting, not direct fetal growth/IQ.

Question 28

A newborn infant who fails to pass meconium within 48 hours and later presents with abdominal distension and dilatation of the proximal colon is probably: a. Hirschsprung disease b. Jejunal atresia c. Meconium ileus d. Malrotation

Answer 28

a. Hirschsprung disease 🧠 Rationale & High-Yield Discussion: 🚼 Hirschsprung disease = aganglionic distal colon, causing functional obstruction. ⏱️ Presents with delayed meconium passage (>48 hrs), abdominal distension, and proximal colonic dilation on imaging. 🚫 Why not the others: ❌ b. Jejunal atresia – Causes bilious vomiting, not delayed meconium alone. ❌ c. Meconium ileus – Seen in cystic fibrosis, but colon is usually microcolon, not dilated. ❌ d. Malrotation – Presents with bilious vomiting and risk of volvulus.

Question 29

Which imaging study is most likely to demonstrate vesicoureteral reflux (VUR)? a. Renal ultrasound b. Voiding cystourethrogram c. Abdominal CT scan d. Intravenous pyelography

Answer 29

b. Voiding cystourethrogram (VCUG) 🧠 Rationale & High-Yield Discussion: 💧 VCUG is the gold standard for diagnosing VUR. Shows retrograde flow of urine from bladder to ureters/kidneys during voiding. 🚫 Why not the others: ❌ a. Renal ultrasound – Can show hydronephrosis but not reflux. ❌ c. Abdominal CT – Not used; high radiation dose. ❌ d. IV pyelography – May show anatomy but less sensitive for reflux.

Question 30

Hemorrhagic disease of the newborn is a deficiency seen more in breast-fed infants because of: a. Lower vitamin C in human milk b. Lower minerals in human milk c. Lower vitamin K in human milk d. None of these

Answer 30

c. Lower vitamin K in human milk 🧠 Rationale & High-Yield Discussion: 🩸 Hemorrhagic disease of the newborn is due to vitamin K deficiency, affecting synthesis of clotting factors II, VII, IX, X. 🤱 Breast milk is low in vitamin K, making exclusively breastfed babies more at risk. 💉 This is why vitamin K injection is given at birth. 🚫 Why not the others: ❌ a. Vitamin C – Adequate in breast milk. ❌ b. Minerals – Not directly linked to hemorrhagic disease. ❌ d. None of these – Incorrect; option c is true.

Question 31

Aspiration of meconium-stained amniotic fluid is usually associated with: a. Congenital heart disease b. Persistent pulmonary hypertension c. Tracheoesophageal fistula d. Cystic fibrosis

Answer 31

b. Persistent pulmonary hypertension 🧠 Rationale & High-Yield Discussion: 🫁 Meconium Aspiration Syndrome (MAS) can lead to airway obstruction, chemical pneumonitis, and persistent pulmonary hypertension of the newborn (PPHN) due to hypoxic vasoconstriction and impaired gas exchange. 🚫 Why not the others: ❌ a. Congenital heart disease – Not directly caused by meconium aspiration. ❌ c. TE fistula – A congenital anomaly, unrelated to meconium aspiration. ❌ d. Cystic fibrosis – Can cause meconium ileus, but not aspiration syndrome.

Question 32

Which of the following is least likely as a cause of vomiting in the first day of life? a. Volvulus b. Duodenal atresia c. Meconium ileus d. Hypertrophic pyloric stenosis

Answer 32

d. Hypertrophic pyloric stenosis FEEDS: a. Volvulus 🧠 Rationale & High-Yield Discussion: 🚫 Pyloric stenosis typically presents at 2–8 weeks of age, not on day 1. ⚠️ It causes projectile non-bilious vomiting, but not in the neonatal period. 🚫 Why not the others: ✅ a. Volvulus – May present with bilious vomiting on day 1, surgical emergency. ✅ b. Duodenal atresia – Presents early with bilious vomiting, “double bubble” sign. ✅ c. Meconium ileus – May also cause early vomiting and abdominal distention.

Question 33

Neonatal hypoglycemia is common in premature infants and SGA. Which of the following is the most common cause of hypoglycemia in those infants? a. Inadequate stores of nutrients b. Glucagon deficiency c. Insulin excess d. Adrenal immaturity

Answer 33

a. Inadequate stores of nutrients 🧠 Rationale & High-Yield Discussion: 🍼 Preterm and SGA infants have reduced glycogen and fat stores, leading to inadequate glucose supply during fasting or stress. 🚫 Why not the others: ❌ b. Glucagon deficiency – Rare; not primary issue. ❌ c. Insulin excess – Seen in infants of diabetic mothers, not SGA/preterm. ❌ d. Adrenal immaturity – May contribute but is not the most common cause.

Question 34

In the newborn period, which of the following is the LEAST common sign of meningitis? a. Lethargy b. Vomiting c. Nuchal rigidity d. Jaundice

Answer 34

c. Nuchal rigidity 🧠 Rationale & High-Yield Discussion: 👶 Neonates often lack classic meningeal signs like nuchal rigidity. 🧠 More common signs: lethargy, poor feeding, vomiting, temperature instability. 🚫 Why not the others: ✅ a. Lethargy – Common and nonspecific but important. ✅ b. Vomiting – Frequent GI sign of CNS infections. ✅ d. Jaundice – Can be associated with sepsis and meningitis in neonates.

Question 35

Which of the following is NOT characteristic of lead poisoning in children? a. GI effects b. Seizures c. Iron deficiency anemia d. Encephalopathy

Answer 35

b. Seizures FEEDS: c. Iron deficiency anemia 🧠 Rationale & High-Yield Discussion: ⚠️ Seizures occur only in severe lead encephalopathy, and are not a typical early sign. ☠️ Common signs include: 🍽️ GI symptoms: abdominal pain, constipation 🧠 Encephalopathy: behavioral changes, learning difficulties 🔻 Microcytic hypochromic anemia due to iron deficiency mimic 🚫 Why not the others: ✅ a. GI effects – Very common. ✅ c. Iron deficiency anemia – Classic finding due to interference with heme synthesis. 🧪 Lead poisoning interferes with heme synthesis, leading to microcytic hypochromic anemia that closely resembles iron deficiency anemia — but the anemia is due to lead toxicity, not due to a true iron deficiency. 🩸 So while lead poisoning mimics iron deficiency anemia and may co-exist with low iron, it can present with anemia — thus option C is a characteristic feature, not the exception. ✅ d. Encephalopathy – Seen in moderate to high lead levels, but develops gradually.

Question 36

Trisomy 21 is associated with: a. Malrotation with volvulus b. AV septal defect c. Cleft lip/palate d. Sensorineural hearing loss

Answer 36

b. AV septal defect 🧠 Rationale: 💙 Trisomy 21 (Down Syndrome) is strongly associated with atrioventricular septal defect (AVSD) due to endocardial cushion defects. 🧠 Also associated with intellectual disability, duodenal atresia, hypotonia, and Brushfield spots. 🚫 Why not the others: ❌ a. Malrotation with volvulus – More common in other GI anomalies, not specifically linked to Down syndrome. ❌ c. Cleft lip/palate – Common in trisomy 13, not trisomy 21. ❌ d. Sensorineural hearing loss – May occur but not a hallmark feature.

Question 37

A 12-year-old patient presents with long, slender hands and feet with spidery fingers and tall stature. He was also found to have dislocation of the lens. The most likely diagnosis is: a. Paget’s disease b. Marfan syndrome c. Cerebral gigantism d. Albright syndrome

Answer 37

b. Marfan syndrome 🧠 Rationale: 🦴 Marfan syndrome is a connective tissue disorder (FBN1 gene) with: 📏 Tall stature, long limbs ✋ Arachnodactyly 👁️ Lens dislocation (ectopia lentis) — typically upward 💔 Risk of aortic root dilation or aneurysm 🚫 Why not the others: ❌ a. Paget’s disease – Affects bone remodeling in older adults. ❌ c. Cerebral gigantism (Sotos syndrome) – Overgrowth with intellectual disability; no lens issues. ❌ d. Albright syndrome – Refers to McCune-Albright, involving café-au-lait spots, precocious puberty, and fibrous dysplasia.

Question 38

A 14-year-old boy with mental retardation has large ears and large testes on physical examination. Which of the following syndromes is associated with these findings? a. Marfan’s syndrome b. Turner’s syndrome c. Fragile X syndrome d. Williams syndrome

Answer 38

c. Fragile X syndrome 🧠 Rationale: 🧬 Fragile X syndrome is the most common inherited cause of intellectual disability. Features include: 👂 Large ears 🍒 Macroorchidism (large testes) 🧠 Developmental delay, behavioral issues (autism-like) 🚫 Why not the others: ❌ a. Marfan’s – Tall stature, not intellectual disability. ❌ b. Turner’s – Affects females, features include short stature, webbed neck. ❌ d. Williams syndrome – Characterized by elfin face, hypercalcemia, and overly friendly personality.

Question 39

A newborn infant was born with ambiguous genitalia. Physical examination of the neonate indicates no palpable gonads, a small phallic structure, and labial fusion with a urogenital opening. Which of the following is the most likely diagnosis? a. Hypopituitarism b. Partial androgen sensitivity c. Congenital adrenal hyperplasia d. Hermaphrodite

Answer 39

c. Congenital adrenal hyperplasia (CAH) 🧠 Rationale: ⚙️ CAH (21-hydroxylase deficiency) is the most common cause of ambiguous genitalia in newborn girls. Due to excess androgen production, leads to: 👶 Female infant with clitoromegaly/labial fusion ⚠️ May cause salt-wasting crisis 🚫 Why not the others: ❌ a. Hypopituitarism – Causes underdevelopment, not virilization. ❌ b. Partial androgen insensitivity – Occurs in genetically male (46,XY) infants with female phenotype and testes present. ❌ d. Hermaphrodite – Outdated term; intersex conditions like CAH are more specific.

Question 40

A 2-month-old baby was brought in for intermittent and unexplained crying. His mother claimed that he was well-fed, healthy, and happy between crying spells. Physical examination was unremarkable. The most probable cause of crying is: a. Hunger b. Infant colic c. Petit mal seizures d. Nightmares

Answer 40

b. Infant colic 🧠 Rationale: 😭 Infantile colic is defined as paroxysmal crying >3 hrs/day, >3 days/week, >3 weeks in an otherwise healthy infant. Peaks around 6 weeks, resolves by 3–4 months. No identifiable cause; reassurance and soothing techniques are key. 🚫 Why not the others: ❌ a. Hunger – Would resolve quickly after feeding. ❌ c. Petit mal seizures – Would present with staring spells, not crying. ❌ d. Nightmares – Rare at this age; baby sleep cycles are not fully developed.

Question 41

A rapidly progressive pneumonia with pyopneumothorax and pneumatoceles is highly suggestive of: a. Staphylococcal pneumonia b. Tuberculous pneumonia c. Mycoplasma pneumonia d. Streptococcal pneumonia

Answer 41

a. Staphylococcal pneumonia 🧠 Rationale: 🔥 Staph aureus causes necrotizing pneumonia characterized by: 🫁 Pneumatoceles (air-filled cysts) 💨 Pyopneumothorax ⚡ Rapid progression and severe systemic illness 🚫 Why not the others: ❌ b. Tuberculous pneumonia – Chronic onset, not rapid; cavitary lesions, not pneumatoceles. ❌ c. Mycoplasma pneumonia – Atypical, gradual onset with dry cough, not necrotizing. ❌ d. Streptococcal pneumonia – Causes lobar pneumonia, no pneumatoceles or pyopneumothorax.

Question 42

A 10-month-old child has a temperature of 40°C for 4 days without other signs. On the 4th day, a maculopapular rash appears on the trunk and the temperature returns to normal. The most likely diagnosis is: a. Rubella b. Varicella c. Roseola infantum d. Rubeola

Answer 42

c. Roseola infantum 🧠 Rationale: 👶 Roseola (HHV-6) presents with: 🌡️ High fever for 3–5 days 👕 Maculopapular rash that appears as fever subsides 🧒 Most common in infants 6 months to 2 years 🚫 Why not the others: ❌ a. Rubella – Rash appears with fever, often starts on face. ❌ b. Varicella – Vesicular rash, crops at different stages. ❌ d. Rubeola (Measles) – Rash appears after prodrome (cough, coryza, conjunctivitis, Koplik spots), spreads cephalocaudal.

Question 43

Which of the following conditions is a sequela of group A beta-hemolytic streptococcal throat infection? a. Impetigo b. Acute rheumatic fever c. Acute glomerulonephritis d. Acute laryngotracheobronchitis

Answer 43

b. Acute rheumatic fever 🧠 Rationale: ❤️ Acute rheumatic fever (ARF) is an autoimmune complication of untreated GAS pharyngitis. 🧬 Due to molecular mimicry targeting joints, heart, skin, and CNS. 🚫 Why not the others: ❌ a. Impetigo – Caused by GAS but not a sequel of pharyngitis. ❌ c. Acute glomerulonephritis – Can follow both impetigo and pharyngitis. ❌ d. Laryngotracheobronchitis – Usually viral (e.g., parainfluenza), not GAS-related.

Question 44

A 12-year-old boy is admitted due to paralysis of both lower extremities. A week prior, the patient had a viral upper respiratory infection. Physical examination reveals loss of tendon reflexes of both lower extremities. CSF protein is elevated and CSF sugar is normal. The most likely diagnosis is: a. Duchenne-Erb's palsy b. Guillain-Barré syndrome c. Acute poliomyelitis d. TB meningitis

Answer 44

b. Guillain-Barré syndrome 🧠 Rationale: ⚡ GBS is an acute demyelinating polyradiculoneuropathy. 🦵 Ascending flaccid paralysis 🎯 Often triggered by viral or GI infections (e.g., Campylobacter) 💉 CSF shows albuminocytologic dissociation (↑ protein, normal glucose) 🚫 Why not the others: ❌ a. Duchenne-Erb’s palsy – A birth injury, not post-viral. ❌ c. Poliomyelitis – Asymmetric flaccid paralysis with pleocytosis in CSF. ❌ d. TB meningitis – Has elevated protein, low glucose, and signs of meningeal irritation.

Question 45

A child has low-grade fever, abdominal pain, arthritis, microscopic hematuria, and a purpuric rash only in the lower extremities. He most likely has: a. Poststreptococcal glomerulonephritis b. Henoch-Schönlein purpura c. Meningococcemia d. Infectious mononucleosis

Answer 45

b. Henoch-Schönlein purpura (HSP) 🧠 Rationale: 💉 HSP (IgA vasculitis) is the most common systemic vasculitis in children. 🎯 Classic tetrad: 🌡️ Low-grade fever 🩸 Palpable purpura (lower extremities) 🦴 Arthritis/arthralgia 🚽 Hematuria/GI involvement 🚫 Why not the others: ❌ a. Post-strep GN – Presents with edema, hematuria, but no purpura/arthritis. ❌ c. Meningococcemia – More toxic appearance, non-blanching rash, shock. ❌ d. Infectious mononucleosis – Presents with fever, lymphadenopathy, splenomegaly, but no purpura or arthritis.

Question 46

Which of the following is the most common clinical manifestation of platelet disorders? a. Spontaneous hemorrhage in brain, lung, and liver b. Hematuria c. Bleeding into skin and mucous membranes d. Gastrointestinal hemorrhage

Answer 46

c. Bleeding into skin and mucous membranes 🧠 Rationale: 🩸 Platelet disorders (e.g. ITP, thrombocytopenia) typically present with: 🔴 Petechiae 🌫️ Purpura 👄 Mucosal bleeding (e.g., gums, nose) 🧬 Platelets are vital for primary hemostasis, which prevents bleeding in superficial tissues. 🚫 Why not the others: ❌ a. Spontaneous hemorrhage in organs – More typical of coagulation factor deficiencies. ❌ b. Hematuria – Rare in platelet disorders; more common in vasculitis or trauma. ❌ d. GI hemorrhage – Less common and more typical of vascular or coagulation disorders.

Question 47

A 12-month-old boy with vesicles and scales in the diaper area, failure to thrive, and chronic diarrhea. The most likely abnormal laboratory finding of this boy is: a. Low serum glucose b. Low serum copper c. Low serum calcium d. Low serum zinc

Answer 47

d. Low serum zinc 🧠 Rationale: ⚠️ These are classic features of acrodermatitis enteropathica, a zinc deficiency. 🩹 Periorificial and diaper rash 🚼 Failure to thrive 🚽 Chronic diarrhea 🚫 Why not the others: ❌ a. Low glucose – Seen in metabolic disorders, not consistent with skin + GI findings. ❌ b. Low copper – Seen in Menkes disease, presents with kinky hair and neurodegeneration. ❌ c. Low calcium – Causes tetany, seizures—not skin rash or diarrhea.

Question 48

Immunodeficiency in a child should be suspected if they show the clinical manifestation of: a. Excessive use of antibiotics by physicians b. Infections occurring at unusual sites c. Repeated viral infections d. Poor growth and development

Answer 48

b. Infections occurring at unusual sites 🧠 Rationale: 🧪 Immunodeficiency is often indicated by: 🦠 Infections at unusual or deep sites (e.g., liver abscesses, bone, joints) 📆 Persistent/recurrent infections 📉 Poor response to standard treatment 🚫 Why not the others: ❌ a. Excessive antibiotic use – Could be due to overprescription, not immune defect. ❌ c. Repeated viral infections – Mild recurrent viruses are common in healthy kids. ❌ d. Poor growth/development – Nonspecific; must be in context of infections.

Question 49

An 8-year-old boy presents with fever, headache, and vomiting. You suspect meningitis and perform a lumbar puncture. CSF analysis shows WBC 145, glucose 55 gm/dL, and protein 180 gm/dL. Gram stain is negative. The most likely diagnosis is: a. Enteroviral meningitis b. Tuberculous meningitis c. Pneumococcal meningitis d. Partially treated bacterial meningitis

Answer 49

d. Partially treated bacterial meningitis FEEDS: b. Tuberculous meningitis 🧠 Rationale: 📉 Partially treated meningitis can result in: 🔬 Negative Gram stain ↑ WBC (mostly neutrophils) ↑ Protein 🔻 Glucose may be normal or slightly low 🧪 Antibiotic pretreatment can sterilize the CSF but leave inflammatory markers. 🚫 Why not the others: ❌ a. Enteroviral – Would have normal/mild protein, normal glucose, and lymphocytic predominance. ❌ b. Tuberculous meningitis Usually shows: -Very high protein -Low glucose (<40 mg/dL) -Lymphocytic predominance In this case, glucose is normal, which argues against TBM. ❌ c. Pneumococcal meningitis – Gram-positive cocci visible if untreated.

Question 50

One of the following clinical manifestations is suggestive of a B-cell defect: a. Graft versus host disease after blood transfusion b. Chronic mucocutaneous candidiasis c. Recurrent bacterial pneumonia, sepsis, or meningitis d. Systemic illness following vaccination with any live virus

Answer 50

c. Recurrent bacterial pneumonia, sepsis, or meningitis 🧠 Rationale: 🧬 B-cell defects (e.g., X-linked agammaglobulinemia, CVID) cause: 🦠 Recurrent infections with encapsulated bacteria: S. pneumoniae, H. influenzae, etc. 🧪 Due to impaired antibody production 🚫 Why not the others: ❌ a. GVHD post-transfusion – Suggests T-cell defect (e.g., SCID). ❌ b. Mucocutaneous candidiasis – Classic for T-cell defects. ❌ d. Reaction to live virus vaccine – Seen in T-cell or combined immunodeficiency.

Question 51

A newborn baby delivered with oligohydramnios by ultrasound, finding of a single umbilical artery may be associated with: a. Hydronephrosis b. Renal agenesis c. Polycystic kidney d. Renal dysplasia

Answer 51

b. Renal agenesis 🧠 Rationale: 🚼 Renal agenesis leads to decreased fetal urine production, causing oligohydramnios. 🚫 A single umbilical artery is a known soft marker for congenital anomalies, especially of the renal and cardiovascular systems. 🚫 Why not the others: ❌ a. Hydronephrosis – May occur with obstruction but doesn’t cause severe oligohydramnios. ❌ c. Polycystic kidney – Can cause oligohydramnios but usually bilateral and familial. ❌ d. Renal dysplasia – Also a possibility, but renal agenesis is more strongly associated.

Question 52

This is a syndrome transmitted by daytime-biting mosquitoes, characterized by biphasic fever, myalgia, rash, and bleeding tendencies: a. Rabies b. Dengue fever c. Poliomyelitis d. Leptospirosis

Answer 52

b. Dengue fever 🧠 Rationale: 🦟 Dengue is caused by the Aedes mosquito, active during the day. 💥 Presents with: Biphasic (saddleback) fever 🩸 Bleeding tendencies 🤕 Myalgia, arthralgia 🌡️ Rash and thrombocytopenia 🚫 Why not the others: ❌ a. Rabies – Transmitted via bites, not mosquito-borne. ❌ c. Poliomyelitis – Fecal-oral route, presents with flaccid paralysis. ❌ d. Leptospirosis – Transmitted via water contaminated with animal urine.

Question 53

Suprapubic aspiration of urine is the gold standard method for urine culture in infants. Which of the following statements is TRUE? a. It is the procedure of choice in toilet-trained children b. The rate of contamination is very low c. It is a non-invasive procedure d. Puncture can be done even in an empty bladder

Answer 53

b. The rate of contamination is very low 🧠 Rationale: 💉 Suprapubic aspiration (SPA) is the gold standard for sterile urine collection in infants. ✅ Very low contamination rate compared to bagged samples. 🚫 Why not the others: ❌ a. Procedure of choice in toilet-trained children – False, clean-catch or midstream preferred. ❌ c. Non-invasive procedure – Invasive, involves needle insertion. ❌ d. Can be done in an empty bladder – Incorrect, bladder must be palpable/full.

Question 54

The most reliable test for the diagnosis of Gastroesophageal reflux disease in children is: a. Endoscopy b. Barium study of GIT c. Scintigraphy d. 24-hour pH probe

Answer 54

d. 24-hour pH probe 🧠 Rationale: 🧪 24-hour esophageal pH monitoring is the gold standard for GERD diagnosis, especially in non-verbal infants. 📉 Measures acid exposure and frequency of reflux episodes. 🚫 Why not the others: ❌ a. Endoscopy – Useful to assess esophagitis, not for measuring reflux. ❌ b. Barium study – Shows anatomy, may miss non-anatomic reflux. ❌ c. Scintigraphy – Can detect aspiration or delayed gastric emptying, but not as sensitive for reflux.

Question 55

A 12-month-old infant presents to the ER because of hoarseness and a barking-type cough. His mother told you that he has had cough and colds a week ago. Physical examination findings include a respiratory rate of 55/min, chest retractions, and flaring, with (+) inspiratory stridor. What is the probable diagnosis? a. Laryngomalacia b. Foreign body aspiration c. Croup d. Acute epiglottitis

Answer 55

c. Croup d. Acute epiglottitis 🧠 Rationale: 🦠 Caused by parainfluenza virus. 👃 Preceded by URI 🐶 Classic signs: -Barking cough -Inspiratory stridor -Hoarseness -Subglottic narrowing on imaging ("steeple sign") 🚫 Why not the others: ❌ a. Laryngomalacia – Congenital, stridor worsens with feeding/crying, but no barking cough. ❌ b. Foreign body aspiration – Sudden onset, usually with asymmetry or choking episode. ❌ d. Acute epiglottitis – Abrupt onset, drooling, toxic appearance, and tripod position.

Question 56

Poliomyelitis is characterized by: a. Symmetric paralysis of voluntary muscles b. Spotty involvement of the neuron in the anterior horn cell in the spinal cord c. The child may present with spasticity in the lower extremities with hyperreflexia d. 80% of cases will present as paralytic illness

Answer 56

b. Spotty involvement of the neuron in the anterior horn cell in the spinal cord 🧠 Rationale: 🦠 Poliovirus affects the anterior horn cells of the spinal cord. 🧠 It leads to asymmetric, flaccid paralysis, often with spotty neuron involvement. 💪 Reflexes are diminished/absent in affected areas. 🚫 Why not the others: ❌ a. Symmetric paralysis – Poliomyelitis is asymmetric. ❌ c. Spasticity with hyperreflexia – Suggests UMN lesion (e.g., cerebral palsy), not LMN disease like polio. ❌ d. 80% as paralytic illness – Wrong, >90% are subclinical or mild; only ~1% develop paralytic disease.

Question 57

Which of the following statements regarding Tuberculous meningitis is NOT TRUE? a. Ventriculitis is seen as a late complication b. Infarction due to arteries is present resulting in hemiparesis c. Hydrocephalus is a complication usually present as early as the 2nd week of illness d. CSF findings will reveal pleocytosis, hypoglycorrhachia, and elevated protein

Answer 57

c. Hydrocephalus is a complication usually present as early as the 2nd week of illness FEEDS: d. CSF findings will reveal pleocytosis, hypoglycorrhachia, and elevated protein 🧠 Rationale: 💧 Hydrocephalus is a common complication, but typically appears later, not as early as the 2nd week. 🧪 TB meningitis is subacute, progressing over weeks. 🚫 Why not the others: ✅ a. Ventriculitis as late complication – True. ✅ b. Infarction from vasculitis → hemiparesis – Common in TBM. ✅ d. CSF: pleocytosis, ↓ glucose (hypoglycorrhachia), ↑ protein – Classic TB meningitis CSF profile.

Question 58

A large-for-gestational-age infant has hepatomegaly, macroglossia, umbilical hernia, and hypoglycemia. The most likely diagnosis is: a. Beckwith-Wiedemann syndrome b. Glycogen storage disease c. Hypopituitarism d. Hyperinsulinism

Answer 58

a. Beckwith-Wiedemann syndrome 🧠 Rationale: 💡 Beckwith-Wiedemann syndrome is a congenital overgrowth disorder with: 📏 LGA 😛 Macroglossia 🧠 Hypoglycemia from hyperinsulinism 🩻 Hepatomegaly, omphalocele/umbilical hernia 🧬 Increased risk of Wilms tumor, hepatoblastoma 🚫 Why not the others: ❌ b. GSD – Also presents with hepatomegaly/hypoglycemia, but not macroglossia or umbilical hernia. ❌ c. Hypopituitarism – Causes growth retardation, not overgrowth. ❌ d. Hyperinsulinism – May explain hypoglycemia, but not the syndromic features.

Question 59

A 5-year-old female has a 1-year history of breast development and pubic hair, Tanner stage 3 on breast and Tanner stage 2 on pubic hair examinations. She had her first menses today. Bone age is equivalent to a 10-year-old girl. What is the most likely diagnosis? a. Premature thelarche b. Premature adrenarche c. Normal, no pubertal disorder d. Central precocious puberty

Answer 59

d. Central precocious puberty FEEDS: a. Premature thelarche 🧠 Rationale: ⏰ CPP is gonadotropin-dependent, with early activation of the HPO axis. 🩸 Menarche, advanced bone age, and Tanner staging >2 confirm puberty. 🧬 More common in girls and often idiopathic. 🚫 Why not the others: ❌ a. Premature thelarche – Breast development without other signs of puberty. ❌ b. Premature adrenarche – Pubic/axillary hair only, no breast or menses. ❌ c. Normal – Puberty before age 8 in girls is precocious.

Question 60

Of the following motor milestones, the one that is most typical of a 24-month-old child is: a. Building a tower of 2 cubes b. Copying a circle c. Scribbling d. Throwing a ball overhand

Answer 60

c. Scribbling 📌 Why? 🖍️ Scribbling begins around 18 months, but at 24 months, the child scribbles in circular patterns and imitates horizontal strokes — making it a continuing and developmentally appropriate skill at this age. The other options: ❌ a. Building a tower of 2 cubes → too early (15 months) ❌ b. Copying a circle → too late (36 months) ❌ d. Throwing ball overhand → listed at 48 months on your chart

Question 61

A 6-month-old infant has had diarrhea and lethargy for 4 days. Findings include: BP 80/50, pulse 150 beats/min, doughy skin, and sunken eyeballs. Creatinine 1.0, BUN 60 mg/dl, Sodium 170 meq/l, K 4.9 meq/l, HCO3 15 meq/l, and glucose 190 mg/dl. Fluid therapy is instituted, and 12 hours later, the patient develops a generalized seizure. The most likely explanation for these findings is: a. Hyperglycemia b. Hyperkalemia c. Rapid correction of hypernatremia d. Rapid correction of metabolic acidosis

Answer 61

c. Rapid correction of hypernatremia 🧠 Rationale: 🧂 Severe hypernatremia (Na⁺ 170) causes the brain to adapt by producing osmolytes. 💧 Rapid correction leads to cerebral edema → seizures and possible herniation. ⚠️ Sodium should be corrected slowly (no more than 10–12 mEq/L per 24 hrs). 🚫 Why not the others: ❌ a. Hyperglycemia – Can cause osmotic diuresis but not acute seizures after rehydration. ❌ b. Hyperkalemia – Would cause arrhythmias, not seizures. ❌ d. Rapid correction of acidosis – Not a typical cause of seizure in this context.

Question 62

A 1300 g male infant is born at 31 weeks gestation to a primigravida whose pregnancy was complicated by spontaneous preterm labor and premature vertex vaginal delivery. The mother received no antenatal steroids, and her membranes spontaneously ruptured just before delivery. At 4 hours of age, the infant develops tachypnea, grunting, alar flaring, and subcostal retraction. The most likely x-ray finding in this infant would be: a. Diffuse coarse infiltrates b. Fine granular infiltrates or white-out lung c. Fluid in interlobar fissures d. Pleural effusion

Answer 62

b. Fine granular infiltrates or white-out lung FEEDS: a. Diffuse coarse infiltrates 🧠 Rationale: 🫁 Classic for Hyaline Membrane Disease / Respiratory Distress Syndrome (RDS) in preterm infants due to surfactant deficiency. 📸 X-ray shows: 🟦 Reticulogranular pattern ("ground-glass") 🎯 Air bronchograms ❄️ May progress to "white-out" lungs 🚫 Why not the others: ❌ a. Diffuse coarse infiltrates – Suggest pneumonia. ❌ c. Fluid in fissures – Typical in TTN (Transient Tachypnea of the Newborn). ❌ d. Pleural effusion – Not common in RDS.

Question 63

A 1400 g baby born at 32 weeks gestation has several episodes of apnea on postnatal day 10. Monitoring reveals cessation in respiration lasting more than 10 seconds, accompanied by bradycardia and cyanosis. Findings on PE, measurement of electrolytes, and CBC are normal. Of the following, the most likely diagnosis is: a. Apnea of prematurity b. Periodic breathing c. Quiet sleep d. Subtle seizures

Answer 63

a. Apnea of prematurity 🧠 Rationale: 🛏️ Common in preterm infants <34 weeks, due to immature brainstem respiratory centers. Characterized by: 🛑 >10 seconds of apnea ❤️ Bradycardia 🔵 Cyanosis Onset typically within the first 2 weeks of life. 🚫 Why not the others: ❌ b. Periodic breathing – Brief pauses (<10 sec) without bradycardia or cyanosis. ❌ c. Quiet sleep – Normal state; does not involve apnea + bradycardia. ❌ d. Subtle seizures – Would have eye deviation, chewing, lip smacking, not apnea + bradycardia pattern.

Question 64

A 6-year-old child is admitted for evaluation of generalized edema. Findings include: serum creatinine 0.5 mg/dl, albumin 1.8 g/dl, cholesterol 300 mg/dl, triglycerides 350 mg/dl, C3 complement 100 mg/dl, ANA (-), and urinalysis 5-10 RBC/hpf with proteinuria of 3+. These findings are most consistent with the diagnosis of: a. IgA nephropathy b. Rapidly progressive acute glomerulonephritis c. Nephrotic syndrome d. Postinfectious AGN

Answer 64

c. Nephrotic syndrome 🧠 Rationale: 🧪 Features of nephrotic syndrome: 🧊 Hypoalbuminemia 🧴 Hyperlipidemia 🧫 Heavy proteinuria 💦 Edema Most likely Minimal Change Disease (MCD) in this age, with normal renal function and complement levels. 🚫 Why not the others: ❌ a. IgA nephropathy – Presents with hematuria and is often post-viral. ❌ b. RPGN – Would have rapidly rising creatinine, usually abnormal C3. ❌ d. Postinfectious AGN – Often with low C3, hypertension, and gross hematuria.

Question 65

An infant was born with a ruddy deep purple appearance with a central hematocrit of 78% volume. You suspect polycythemia. In the investigation of the possible cause of this, it is important to ask the mother if: a. She had a hematologic problem b. She has uncontrolled diabetes during pregnancy c. She received blood transfusion during pregnancy d. She took antihypertensive drugs during pregnancy

Answer 65

b. She has uncontrolled diabetes during pregnancy FEEDS: c. She received blood transfusion during pregnancy 🧠 Rationale: 🍭 Maternal diabetes can cause fetal hypoxia, which stimulates erythropoiesis → polycythemia. 🩸 Hct >65% in neonates = neonatal polycythemia, can cause hyperviscosity syndrome. 🚫 Why not the others: ❌ a. Hematologic problem – Would be relevant if familial, but less likely cause here. ❌ c. Blood transfusion – Would not affect fetal hematocrit. ❌ d. Antihypertensives – Not associated with polycythemia.

Question 66

At the end of the first year, an infant can do one of the following milestones of development: a. Able to point to nose, eyes, and hair b. Able to stand alone and take a few steps c. May run, ride a bike d. May crawl upstairs

Answer 66

b. Able to stand alone and take a few steps 🧠 Rationale: 🎂 At 12 months (end of 1st year): 🚶 Stands alone, may take first steps 👋 Waves bye-bye, says mama/dada 🧱 May build tower of 2 cubes 🚫 Why not the others: ❌ a. Point to body parts – Seen closer to 15–18 months. ❌ c. Run/ride bike – Running begins around 18–24 months; biking is much later (3–5 years). ❌ d. Crawl upstairs – Occurs before 12 months, not “new” at the end of the first year.

Question 67

At 1 minute of life, a newborn's respiratory rate is slow and irregular with a heart rate of 70 beats/min. There is some flexion of the extremities. He does not respond when a nasal catheter is placed into his nose, and he is blue and pale. What is his Apgar score? a. 2 b. 3 c. 4 d. 5

Answer 67

b. 3 A = 0 P = 1 G = 0 A = 1 R = 1

Question 68

The clinical features of vitamin K deficiency include all of the following EXCEPT: a. Factors II, VII, IX, and X are decreased b. Bleeding from any site c. More common in premature than full-term infants d. Platelet count and fibrinogen level are decreased

Answer 68

d. Platelet count and fibrinogen level are decreased 🧠 Rationale: 🧬 Vitamin K is needed for activation of clotting factors II, VII, IX, X. 🩸 Deficiency leads to bleeding, especially in newborns (esp. preterms). ⚠️ Platelet count and fibrinogen are normal in Vitamin K deficiency. 🚫 Why not the others: ✅ a. Factors ↓ – True ✅ b. Bleeding – True (e.g., GI, intracranial, umbilicus) ✅ c. More common in preterms – True (lower stores, less hepatic function)

Question 69

A 3200-gram term newborn of a G3P3 mother is noted to be jaundiced when examined on postnatal day 10. Total bilirubin is 9 mg/dl, direct bilirubin is 0.8 mg/dl, and hemoglobin is 15 g/dl. Blood type O+ for both mother and baby. The baby has been purely breastfed since birth. Of the following, the most likely explanation for the hyperbilirubinemia is: a. Biliary atresia b. Breast milk jaundice c. Inspissated bile syndrome d. Neonatal hepatitis

Answer 69

b. Breast milk jaundice 🧠 Rationale: 👶 Breast milk jaundice appears after day 5, peaks at 10–14 days, persists but benign. 🍶 Related to enzyme inhibition that slows bilirubin conjugation. Labs: Unconjugated hyperbilirubinemia, baby is healthy, breastfeeding well. 🚫 Why not the others: ❌ a. Biliary atresia – Would show direct hyperbilirubinemia, pale stools. ❌ c. Inspissated bile – Rare, seen in sepsis or hemolysis. ❌ d. Neonatal hepatitis – Would have elevated direct bilirubin, abnormal liver enzymes.

Question 70

The best laboratory test to confirm hypothyroidism is: a. T4 b. TSH assay c. Thyroid scan d. Thyroid antibodies

Answer 70

b. TSH assay 🧠 Rationale: 🔍 TSH is the most sensitive marker for primary hypothyroidism. 📉 In congenital hypothyroidism, TSH is high, T4 is low. Used for newborn screening. 🚫 Why not the others: ❌ a. T4 – Useful but not confirmatory alone. ❌ c. Thyroid scan – Detects anatomy but not hormone status. ❌ d. Thyroid antibodies – More relevant in autoimmune hypothyroidism, not neonatal cases.

Question 71

The primary defect in congenital virilizing adrenal hyperplasia is: a. Inability to produce cortisol b. Excessive ACTH secretion c. Increase in masculinizing sex hormones d. Presence of both ovarian and testicular elements

Answer 71

a. Inability to produce cortisol 🧠 Rationale: 🧬 Most common form: 21-hydroxylase deficiency 🚫 Impaired cortisol synthesis → loss of negative feedback → ↑ ACTH ⏫ This drives excess androgen production, leading to virilization 🚫 Why not the others: ❌ b. Excessive ACTH – Is secondary to cortisol deficiency, not the primary defect ❌ c. Increased androgens – Occur secondary to enzyme defect ❌ d. Ovarian/testicular elements – Seen in true hermaphroditism, not CAH

Question 72

The initial treatment of diabetic ketoacidosis is: a. Insulin therapy b. Replacement of fluid and electrolytes c. Treatment of precipitating factors d. Diabetic diet

Answer 72

b. Replacement of fluid and electrolytes 🧠 Rationale: 💧 First step in DKA is volume resuscitation to restore perfusion Then correct: 🧂 Electrolytes (especially potassium) 💉 Insulin comes after initial fluid resuscitation 🚫 Why not the others: ❌ a. Insulin therapy – Essential, but not first ❌ c. Precipitating factors – Treated after stabilization ❌ d. Diabetic diet – Irrelevant in acute setting

Question 73

A suction catheter used to clear the airway can be frequently passed into the stomach. This maneuver can be utilized to diagnose which of the following conditions? a. Esophageal atresia b. Diaphragmatic hernia c. Imperforate anus d. Pyloric stenosis

Answer 73

a. Esophageal atresia 🧠 Rationale: 🧪 In esophageal atresia, catheter cannot reach the stomach (it coils in upper pouch) 🎯 Failure to pass a nasogastric tube is a diagnostic clue 🚫 Why not the others: ❌ b. Diaphragmatic hernia – Presents with respiratory distress and scaphoid abdomen ❌ c. Imperforate anus – Diagnosed by perineal inspection or absence of meconium passage ❌ d. Pyloric stenosis – Diagnosed later; catheter passes normally

Question 74

A term newborn infant presents with increased oral secretions and respiratory distress soon after birth. What is the most likely diagnosis? a. Tracheoesophageal fistula b. Diaphragmatic hernia c. Respiratory distress syndrome d. Congenital pneumonia

Answer 74

a. Tracheoesophageal fistula (TEF) 🧠 Rationale: 🍼 Classic signs of TEF with esophageal atresia: 💧 Frothy secretions 🌬️ Respiratory distress ❌ Inability to pass NG tube Often presents immediately after birth 🚫 Why not the others: ❌ b. Diaphragmatic hernia – Scaphoid abdomen, bowel sounds in chest ❌ c. RDS – Occurs in preemies, due to surfactant deficiency ❌ d. Pneumonia – Can cause distress but usually not frothy oral secretions

Question 75

A 2-month-old infant has erythema on her trunk, face, scalp, and extensor surfaces. Her mother notes that at times her cheeks get red and weepy. Which of the following is the most likely diagnosis? a. Drug allergy b. Contact dermatitis c. Infantile eczema d. Cold urticaria

Answer 75

c. Infantile eczema (atopic dermatitis) 🧠 Rationale: 🧴 Presents around 2 months 👶 Affects: Face, scalp, extensor surfaces Red, itchy, sometimes weepy patches Associated with family history of allergy/asthma 🚫 Why not the others: ❌ a. Drug allergy – More acute, widespread, not limited to typical eczema areas ❌ b. Contact dermatitis – Rare in infants; not usually widespread ❌ d. Cold urticaria – Presents as wheals/hives, not eczematous rash

Question 76

A 12-year-old male adolescent presents with a 1-month history of fever, weight loss, fatigue, and pain and localized swelling of the right distal femur. X-ray of the right leg reveals periosteal new bone formation described as “sunburst.” Which of the following is the most likely diagnosis? a. Ewing's sarcoma b. Osteosarcoma c. Chronic osteomyelitis d. Eosinophilic granuloma

Answer 76

b. Osteosarcoma 🧠 Rationale: 🔬 Osteosarcoma is the most common primary bone tumor in adolescents. 📸 X-ray finding: "Sunburst" pattern and Codman's triangle (periosteal elevation). 🦴 Commonly affects metaphysis of long bones (e.g., distal femur, proximal tibia). 🔥 Constitutional symptoms like fever and weight loss may also be present. 🚫 Why not the others: ❌ a. Ewing's sarcoma – Onion-skin appearance; usually diaphyseal. ❌ c. Chronic osteomyelitis – May mimic bone tumor but lacks aggressive periosteal reaction. ❌ d. Eosinophilic granuloma – Lytic bone lesion; seen in Langerhans cell histiocytosis, not sunburst.

Question 77

An obese adolescent male presents with intermittent knee pain for 2 weeks. He has no known history of trauma but does play soccer twice a week. He has had no fever or upper respiratory symptoms. The knee exam is normal; however, the hip exam demonstrates limited internal rotation and mild tenderness. Which of the following is the most likely cause of this patient's limp based on the history and exam? a. Legg-Calvé-Perthes disease b. Transient synovitis c. Osgood-Schlatter disease d. Slipped capital femoral epiphysis

Answer 77

d. Slipped capital femoral epiphysis (SCFE) 🧠 Rationale: ⚠️ Classic in obese adolescent males, ages 10–16. 💥 Presents with: Hip/knee pain Limited internal rotation Antalgic gait or limp 🎯 Pathophysiology: displacement of femoral head from neck at growth plate. 🚫 Why not the others: ❌ a. Legg-Calvé-Perthes – Affects younger children (4–8 yrs), not obese teens. ❌ b. Transient synovitis – Often post-viral, resolves quickly, no obesity link. ❌ c. Osgood-Schlatter – Causes tibial tuberosity pain, not hip symptoms.

Question 78

A 1-month-old female infant, born at full term, is noted to have a harsh holosystolic Grade 3/6 heart murmur heard best at the left lower sternal border. The infant is not cyanotic and does not have hepatomegaly, feeds without tachypnea or diaphoresis, and weight gain is appropriate. There is no cardiomegaly on chest x-ray. Which of the following is the most likely diagnosis? a. Ventricular septal defect b. Atrial septal defect c. Patent ductus arteriosus d. AV septal defect

Answer 78

a. Ventricular septal defect (VSD) 🧠 Rationale: 💓 VSD = most common congenital heart defect. 🎵 Harsh holosystolic murmur at left lower sternal border. 😊 Small VSDs may be asymptomatic, with normal growth and feeding. 🚫 Why not the others: ❌ b. ASD – Causes systolic ejection murmur, best at left upper sternal border. ❌ c. PDA – Continuous “machinery” murmur at left infraclavicular area.

Question 79

A 15-year-old patient with asthma presents to the emergency room with shortness of breath. He has used his inhaler three times in the past hour. His respiratory rate is 34 with a pulse oxygenation measurement of 92%. However, no wheezing is heard on exam. Which of the following is the most appropriate initial pharmacologic intervention? a. Oral bronchodilators b. Nebulized bronchodilators c. Nebulized cromolyn d. Intravenous corticosteroids

Answer 79

b. Nebulized bronchodilators 🧠 Rationale: 🚨 Absence of wheezing = silent chest = severe airflow obstruction! 🫁 First-line emergency management = nebulized short-acting beta-agonists (e.g., albuterol) 💉 May combine with systemic corticosteroids for inflammation control. 🚫 Why not the others: ❌ a. Oral bronchodilators – Too slow for acute distress. ❌ c. Cromolyn – Prophylactic; not useful in acute attack. ❌ d. IV steroids – Used after bronchodilators, not first-line for immediate relief.

Question 80

A child presents to the ER with a complaint of frequent short staring spells. The spells last only a few seconds each; however, the child is not responsive during the spells, and they are increasing in frequency. The parents are concerned. Which of the following diagnostic procedures is most likely to yield a definitive diagnosis? a. Cerebrospinal fluid analysis b. Electroencephalogram c. Head CT scan d. Magnetic Resonance Imaging

Answer 80

b. Electroencephalogram (EEG) 🧠 Rationale: ⚡ Classic presentation of absence seizures: Short (<20 seconds) Sudden onset/cessation No post-ictal confusion 📈 EEG shows 3 Hz spike-and-wave discharges → definitive for diagnosis. 🚫 Why not the others: ❌ a. CSF analysis – Not useful; no infection suspected. ❌ c. CT scan – May miss subtle changes; not useful for absence seizures. ❌ d. MRI – Useful for structural lesions, but not needed if clinical and EEG confirm seizure type.

Question 81

A full-term 4000-g male infant is noted to be cyanotic 6 hours after birth. He has increased pulmonary vascular markings on chest x-ray without cardiomegaly. He is tachypneic with good pulses and perfusion. There is no heart murmur, but there is a loud single S2. The ECG is normal for a newborn. The preductal and postductal oxygen saturation levels are 65%. A hyperoxia test reveals a preductal right radial arterial blood gas while breathing 100% of pH 7.33, PCO2 35, PO2 35, HCO3 21, BE -1.5. Which of the following congenital heart defects is most likely? a. D-transposition of the great arteries with intact ventricular septum b. Tetralogy of Fallot c. Total anomalous pulmonary venous return with obstruction d. Tricuspid atresia

Answer 81

a. D-transposition of the great arteries with intact ventricular septum (D-TGA) 🧠 Rationale: 🔄 D-TGA causes parallel circulation: oxygenated and deoxygenated blood don’t mix. 📸 CXR: increased pulmonary vascularity, no cardiomegaly, possible “egg-on-a-string” later. 🫁 Hyperoxia test: PO₂ stays low (<100 mmHg) even with 100% O₂, confirms cyanotic CHD. 🎯 Single S2, no murmur, tachypnea — classic early D-TGA sign. 🚫 Why not the others: ❌ b. TOF – Typically has murmur from RVOT obstruction + decreased pulmonary vascular markings. ❌ c. TAPVR with obstruction – Usually has profound cyanosis, respiratory distress, and cardiomegaly. ❌ d. Tricuspid atresia – Often presents with a murmur and decreased pulmonary blood flow.

Question 82

A newborn infant with suspected congenital heart disease is noted to have no thymic shadow on chest x-ray. Which of the following is the most likely electrolyte abnormality? a. Hypocalcemia b. Hypercalcemia c. Hypokalemia d. Hyperkalemia

Answer 82

a. Hypocalcemia 🧠 Rationale: 🧬 DiGeorge syndrome (22q11 deletion) → absent thymus, parathyroid hypoplasia 🔻 Leads to: 🧠 Hypocalcemia → seizures ❤️ Conotruncal cardiac defects 💊 T-cell immunodeficiency (no thymic shadow) Catch-22 Mnemonic for DiGeorge Syndrome: C – Cardiac defects (especially conotruncal anomalies like Tetralogy of Fallot, truncus arteriosus, interrupted aortic arch) A – Abnormal facies (e.g., low-set ears, small chin, hypertelorism) T – Thymic hypoplasia/aplasia (leads to T-cell immunodeficiency) C – Cleft palate (or other palate abnormalities) H – Hypocalcemia (due to parathyroid hypoplasia, can cause tetany or seizures) 22 – Microdeletion at chromosome 22q11.2 🚫 Why not the others: ❌ b. Hypercalcemia – Opposite of expected. ❌ c/d. Hypo-/Hyperkalemia – Not typically part of DiGeorge.

Question 83

A 3-year-old girl is diagnosed with new-onset insulin-dependent diabetes mellitus. Which of the following laboratory findings is consistent with diabetic ketoacidosis? a. Hypoglycemia b. Hypercarbia c. Ketones in urine d. High venous blood pH

Answer 83

c. Ketones in urine 🧠 Rationale: 🔍 DKA triad: hyperglycemia, ketonemia/ketonuria, and metabolic acidosis. ✅ Urine ketones = fast, reliable screening for ketosis. 🩸 Will also show low pH, low HCO₃, high anion gap. 🚫 Why not the others: ❌ a. Hypoglycemia – DKA = hyperglycemia. ❌ b. Hypercarbia – DKA causes hypocarbia from compensatory hyperventilation. ❌ d. High pH – DKA = low pH (acidosis).

Question 84

Which of the following electrolyte abnormalities is consistent with pyloric stenosis? a. Na 134, K 4.8, Cl 114, HCO3 9 b. Na 135, K 3.5, Cl 86, HCO3 37 c. Na 130, K 5.0, Cl 102, HCO3 14 d. Na 128, K 6.0, Cl 95, HCO3 21 e. Na 150, K 6.0, Cl 110, HCO3 25

Answer 84

b. Na 135, K 3.5, Cl 86, HCO3 37 Electrolytes * Sodium (Na⁺): 136–146 mEq/L * Potassium (K⁺): 3.5–5.0 mEq/L * Chloride (Cl⁻): 95–105 mEq/L * Bicarbonate (HCO₃⁻): 22–28 mEq/L 🧠 Rationale: 💥 Classic hypochloremic, hypokalemic metabolic alkalosis 🍼 Due to prolonged vomiting of HCl → loss of Cl⁻, K⁺, and H⁺ → ↑ HCO₃⁻ 🚫 Why not the others: ❌ a/c/d/e – Inconsistent with the alkalotic pattern or have acidosis/elevated K not expected in pyloric stenosis.

Question 85

A 5-year-old boy presents to the OPD clinic with fever and a new 3/6 systolic ejection murmur heard best at the right upper sternal border. On extremity examination, splinter hemorrhages and petechiae are noted. Which of the following is the most likely diagnosis based on the clinical description? a. Infective endocarditis b. Rheumatic heart disease c. Kawasaki's disease d. Poststreptococcal glomerulonephritis

Answer 85

a. Infective endocarditis 🧠 Rationale: ❤️ Classic signs: 🎧 New murmur 🩸 Splinter hemorrhages, petechiae 💡 May also have Osler nodes, Janeway lesions 🔬 Often follows bacteremia, especially with cardiac risk factors 🚫 Why not the others: ❌ b. RHD – More chronic, post-strep, presents with arthritis/carditis. ❌ c. Kawasaki disease – Diffuse rash, conjunctivitis, cracked lips, not focal murmur or petechiae. ❌ d. PSGN – Presents with hematuria, edema, HTN, not murmur + embolic signs.

Question 86

A 7-month-old infant presents at the ER following a seizure that resolved without intervention. She has a history of fever and 2 days of diarrhea. Her WBC is elevated, and a stool sample is full of mucus and streaked with blood, but she appears nontoxic and is well hydrated. Which of the following pathogens is the most likely cause of diarrhea? a. Shigella dysenteriae b. Vibrio cholerae c. Salmonella typhi d. Yersinia enterocolitica

Answer 86

a. Shigella dysenteriae 🧠 Rationale: 💥 Shigella commonly causes: -High fever -Bloody, mucous diarrhea -🚨 Febrile seizures in infants/toddlers 🔬 Stool shows WBCs, RBCs, and positive culture for Shigella 🚫 Why not the others: ❌ b. Vibrio cholerae – Profuse watery, non-bloody diarrhea ("rice-water stool") ❌ c. Salmonella typhi – Typhoid fever has stepwise fever, bradycardia, rose spots, not bloody diarrhea in infants ❌ d. Yersinia enterocolitica – Can mimic appendicitis; less commonly causes seizures

Question 87

Crops of papular, vesicular, pustular lesions starting on the trunk and spreading to the extremities is the classic description of which of the following infections? a. Varicella b. Erythema infectiosum (fifth disease) c. Roseola infantum d. Rubella

Answer 87

a. Varicella (chickenpox) 🧠 Rationale: 🐔 Classic presentation of chickenpox: Crops of lesions in different stages Starts on trunk, spreads outward Includes papules → vesicles → pustules → crusts 🚫 Why not the others: ❌ b. Fifth disease – "Slapped cheek" rash, lacy body rash, no vesicles ❌ c. Roseola – High fever → rash after fever resolves, not vesicular ❌ d. Rubella – Fine maculopapular rash, face-to-foot spread, no crops/vesicles

Question 88

A 4-year-old who has recently been started on potassium-sparing diuretics develops muscle weakness and tetany. His STAT serum potassium level is 7.7, with no hemolysis noted. An electrocardiogram is performed, and peaked T waves are noted. What is the most appropriate initial treatment? a. Intravenous glucose b. Intravenous calcium gluconate c. Intravenous plain NSS bolus d. Hemodialysis

Answer 88

b. Intravenous calcium gluconate 🧠 Rationale: ⚡ Calcium gluconate stabilizes the cardiac membrane in severe hyperkalemia 🚫 Does not lower K⁺, but prevents fatal arrhythmias Next steps: insulin + glucose, beta-agonists, diuretics, dialysis 🚫 Why not the others: ❌ a. IV glucose – Must be paired with insulin to shift K⁺ intracellularly ❌ c. NSS – Doesn’t help acutely with high K⁺ ❌ d. Hemodialysis – Used if refractory, but not initial intervention

Question 89

A 15-year-old adolescent female presents to the ER with a history of recent acetaminophen ingestion. What is the most common significant morbidity associated with this ingestion? a. Cardiac arrhythmias b. Malignant hypertension c. Seizures d. Hepatotoxicity

Answer 89

d. Hepatotoxicity 🧠 Rationale: 🩸 Acetaminophen toxicity leads to hepatic necrosis 🧪 Peak hepatotoxicity: 48–72 hours post-ingestion 💊 Treated with N-acetylcysteine (NAC) 🚫 Why not the others: ❌ a. Arrhythmias – Common in TCA or digoxin overdose ❌ b. Malignant hypertension – Not linked to acetaminophen ❌ c. Seizures – Seen in INH, theophylline, or bupropion overdose

Question 90

Which of the following statements about neural tube defects (NTD) is true? a. A low maternal serum alpha-fetoprotein level is associated with an increased risk of a neural tube defect in the fetus. b. There is no increased risk of a neural tube defect in a second child when the first child is born with a meningomyelocele. c. Maternal folic acid supplementation reduces the incidence of neural tube defects. d. Children with spina bifida are paralyzed in their lower extremities.

Answer 90

c. Maternal folic acid supplementation reduces the incidence of neural tube defects FEEDS: a. A low maternal serum alpha-fetoprotein level is associated with an increased risk of a neural tube defect in the fetus. 🧠 Rationale: ✅ Folic acid before conception and in early pregnancy significantly reduces NTD risk 📊 Includes anencephaly, spina bifida, and meningomyelocele 🚫 Why not the others: ❌ a. Low MSAFP – Associated with Down syndrome, not NTD ❌ b. No increased risk – Incorrect; recurrence risk ~2–3% ❌ d. All children with spina bifida are paralyzed – Not true; severity varies by lesion level

Question 91

A 1-year-old male infant presents with a hemoglobin of 7.5 and a hematocrit of 22%. The mean corpuscular volume is 65 fL, and the reticulocyte count is 1%. What is the most likely cause of anemia in the child? a. Iron deficiency anemia b. Transient erythroblastopenia of childhood c. Thalassemia syndrome d. Anemia of chronic disease

Answer 91

a. Iron deficiency anemia 🧠 Rationale: 📉 Microcytic (MCV < 80 fL) + low reticulocyte count = decreased production 🍽️ Most common cause in infants = dietary iron deficiency (post-weaning, milk-heavy diet) 🧪 Labs: Low Hb, Hct, low MCV, low Retic count 🚫 Why not the others: ❌ b. TEC – Causes normocytic anemia with retic low, typically post-viral ❌ c. Thalassemia – Also microcytic but retic count elevated, and more severe anemia ❌ d. Anemia of chronic disease – Rare in infants; MCV usually normal or low-normal

Question 92

A 5-year-old boy presents to the OPD with a chief complaint of periorbital edema. On physical examination, heart, lung, and abdominal findings are normal. However, his hands and feet are edematous. Urinalysis showed +4 protein but no blood. What is the most likely etiology of this child's edema? a. Urinary tract infection b. Membranous glomerulopathy c. Focal segmental glomerulosclerosis d. Minimal change disease

Answer 92

d. Minimal change disease 🧠 Rationale: 🩸 Most common cause of nephrotic syndrome in children. 📌 Triad: -Heavy proteinuria -Hypoalbuminemia -Edema 🧪 Urine: +4 protein, no blood 🩺 Normal BP, normal renal function 🚫 Why not the others: ❌ a. UTI – Would have WBCs, bacteriuria, no heavy proteinuria ❌ b. Membranous GN – Rare in kids, more common in adults ❌ c. FSGS – More severe, resistant to steroids, often hematuria or hypertension

Question 93

A 3-year-old male patient presents with knee hemarthrosis after falling on his knee. There is no history of spontaneous bleeding. There is no history of epistaxis, gingival bleeding, or cutaneous bruising. The child's maternal grandfather had frequent spontaneous bleeding and hemarthroses after trauma on multiple occasions. Laboratory results revealed a prolonged PTT, normal PT, and a platelet count of 150,000. The factor VIII is low, and the factor IX level is normal. What is the most likely diagnosis? a. Idiopathic thrombocytopenic purpura b. von Willebrand's disease c. Vitamin K deficiency d. Hemophilia A

Answer 93

d. Hemophilia A 🧠 Rationale: 🧬 X-linked disorder → family history 🩸 Factor VIII deficiency -Prolonged aPTT -Normal PT -Normal platelets 🤕 Presents with joint bleeding after minor trauma 🚫 Why not the others: ❌ a. ITP – Isolated thrombocytopenia with mucocutaneous bleeding, not hemarthrosis ❌ b. vWD – Usually milder, mucosal bleeding, platelet function defect ❌ c. Vit K deficiency – Affects factors II, VII, IX, X → prolonged PT & PTT

Question 94

A 3-year-old boy presents to the pediatrician with fever, pallor, anorexia, joint pain, petechiae, and hepatosplenomegaly. Which of the following is the most likely diagnosis? a. Acute lymphoblastic leukemia b. Acute myelogenous leukemia c. Juvenile chronic myelogenous leukemia d. Aplastic anemia

Answer 94

a. Acute lymphoblastic leukemia (ALL) 🧠 Rationale: 🎯 Most common childhood cancer 🧬 Symptoms: -Bone marrow failure: anemia, thrombocytopenia, neutropenia -Bone/joint pain, hepatosplenomegaly 🧪 Labs: anemia, leukocytosis/leukopenia, thrombocytopenia 🚫 Why not the others: ❌ b. AML – Less common in young children, often presents with gingival hyperplasia ❌ c. JCML – Chronic, more insidious course ❌ d. Aplastic anemia – Pancytopenia without HSM or joint pain

Question 95

A neonate born at 28 weeks' gestation is now 2 weeks of age. Nasogastric feeds are started. Forty-eight hours after starting feeds, the neonate develops a distended abdomen, bloody stool, pneumatosis intestinalis, and free air on abdominal radiograph. Laboratory studies reveal thrombocytopenia. The infant becomes persistently hypotensive despite maximal medical therapy. The most likely diagnosis is: a. Late onset sepsis b. Aspiration pneumonia c. Malrotation with volvulus d. Necrotizing enterocolitis

Answer 95

d. Necrotizing enterocolitis (NEC) 🧠 Rationale: ⚠️ Common in preterm infants starting enteral feeds 🔥 Pathophysiology: intestinal ischemia + bacterial invasion 📸 X-ray: Pneumatosis intestinalis, portal venous gas, free air = bowel perforation 🚫 Why not the others: ❌ a. Late-onset sepsis – May have GI signs, but lacks pneumatosis on imaging ❌ b. Aspiration pneumonia – Respiratory issue, not GI with blood in stool ❌ c. Malrotation/volvulus – Sudden bilious vomiting, not bloody stool initially

Question 96

Which of the following is the proper initiation sequence of secondary sexual development in the male? a. Testicular enlargement, penile enlargement, height growth spurt, and pubic hair b. Pubic hair, testicular enlargement, penile enlargement, height growth spurt c. Testicular enlargement, penile enlargement, pubic hair, height growth spurt d. Penile enlargement, height growth spurt, testicular enlargement, pubic hair

Answer 96

c. Testicular enlargement, penile enlargement, pubic hair, height growth spurt FEEDS: a. Testicular enlargement, penile enlargement, height growth spurt, and pubic hair 🧠 High-Yield Rationale (Normal Male Pubertal Sequence): 1. Testicular enlargement – 🔑 first sign of puberty (Tanner Stage 2) 2. Penile enlargement – follows testicular growth 3. Pubic hair development – appears after penile growth (Tanner Stage 3) 4. Growth spurt – comes after pubic hair, typically in Tanner Stage 4 ❌ Why choice a is wrong: It incorrectly places the growth spurt before pubic hair development. 🔑 Clinical Pearl: Testes first, hair later. Growth comes after hair in boys.

Question 97

A 6-year-old boy who received trimethoprim-sulfamethoxazole for otitis media presents to the ER with high fever; target lesions on the palms and soles, trunk, and the extensor surfaces of the extremities; and bullous lesions on his mucous membranes. What type of hypersensitivity rash does this child have? a. Bullous impetigo b. Toxic epidermal necrolysis c. Erythema multiforme d. Stevens-Johnson syndrome

Answer 97

d. Stevens-Johnson syndrome (SJS) 🧠 Rationale: 💊 Often triggered by medications (e.g., sulfa drugs) 🛑 Mucosal involvement + targetoid rash 🌡️ High fever, sick-looking child 🧪 Type IV delayed-type hypersensitivity 🚫 Why not the others: ❌ a. Bullous impetigo – Caused by Staph, superficial, no mucosal involvement ❌ b. TEN – More severe version of SJS (>30% BSA detachment) ❌ c. Erythema multiforme – Target lesions but no mucosal involvement, usually post-viral (HSV)

Question 98

A newborn male child has a flat facial profile, upslanted palpebral fissures, epicanthal folds, a small mouth with a protruding tongue, small genitalia, and simian creases on his hands. What chromosomal disorder does this child have? a. Trisomy 21 b. Trisomy 18 c. Trisomy 13 d. Turner's syndrome

Answer 98

a. Trisomy 21 (Down syndrome) 🧠 Rationale: 🧬 Classic features of Down syndrome: 🧒 Flat facies, upslanted palpebral fissures 👅 Macroglossia ✋ Single palmar crease 🧠 Risk of intellectual disability 💛 Associated with AV septal defects 🚫 Why not the others: ❌ b. Trisomy 18 (Edwards) – Clenched fists, rocker-bottom feet ❌ c. Trisomy 13 (Patau) – Midline defects: cleft lip/palate, holoprosencephaly ❌ d. Turner’s – 45,X, affects females, with webbed neck, lymphedema

Question 99

A 4-year-old boy presents with abrupt-onset petechiae and ecchymoses. Other than the skin findings, the child appears well and is hemodynamically stable. No splenomegaly is noted. A complete blood count reveals a normal white blood cell count, a normal hematocrit, and a platelet count of 30,000. Large platelets are seen on the peripheral smear. No premature white cell forms are seen on peripheral smear. The parent reports that the child had a viral illness 2 weeks before presentation. Which of the following is the most likely diagnosis? a. Henoch-Schönlein purpura b. Acute leukemia c. Disseminated intravascular coagulation d. Idiopathic thrombocytopenic purpura

Answer 99

d. Idiopathic thrombocytopenic purpura (ITP) 🧠 Rationale: 🦠 Often follows a viral illness 🧫 Platelet count <100k, isolated thrombocytopenia 🧪 Normal WBC & RBC 😌 Well-appearing child, no organomegaly 🚫 Why not the others: ❌ a. HSP – Palpable purpura + abdominal pain, joint involvement, normal platelets ❌ b. Leukemia – Often has abnormal WBC, blasts on smear, systemic illness ❌ c. DIC – Associated with sick, unstable patients, abnormal coagulation panel

Question 100

You are called to the NICU to evaluate a newborn girl for intrauterine growth retardation. On physical examination, plotting on the growth chart, she is below the fifth percentile for weight, length, and head circumference. She also has hepatosplenomegaly. Cranial ultrasound shows periventricular calcifications. Which of the following is the most likely cause of these findings? a. Herpes simplex virus b. Toxoplasmosis c. Placental insufficiency d. Cytomegalovirus

Answer 100

d. Cytomegalovirus (CMV) 🧠 Rationale: 🧠 CMV = most common congenital infection 🎯 Features: - Periventricular calcifications 🏋️ IUGR 🧫 Hepatosplenomegaly, thrombocytopenia 🦻 Sensorineural hearing loss (long-term) 🚫 Why not the others: ❌ a. HSV – Skin, eye, mouth lesions + encephalitis, but not classic for IUGR + calcifications ❌ b. Toxoplasmosis – Intracranial calcifications (diffuse) + chorioretinitis ❌ c. Placental insufficiency – IUGR only; no calcifications or hepatosplenomegaly