Infections

Question 1

AOM v. Otitis Media w/ Effusion

Answer 1

• If see middle ear effusion on exam must then determine if inflammation present or not
• Middle ear effusion + inflammation = AOM
• Middle ear effusion w/o inflammation = otitis media w/ effusion
• Effusion alone causes dec mobility, color change and opacity
• Signs of acute infection/AOM include fullness, bulging, ear pain (otalgia) and redness of TM (redness only seen in 20% cases)

Question 2

Aspects of Otoscope Exam

Answer 2

• C - color
• O - other conditions (perforation, atrophy, sclerosis, fluid level)
• M- mobility of TM
• P- position (bulging, full, neutral, retracted)
• L-lighting
• E- entire surface
• T- translucency (translucent, semi-opaque or opaque)
• E - external auditory canal (note if displaced, inflamed, deformed or has foreign body)
• S - seal

Question 3

Tx AOM

Answer 3

• high dose amoxicillin; second line is amox-clavulanic acid or cephalosporin (esp in kids < 24 mo)
• If > 24 mo and mild symptoms may opt for watchful waiting; because of antiobiotic resistance

Question 4

Sinusitis in Kids (organisms)

How can you tell viral v bacterial?

Answer 4

Most often viral (parainfluenza or RSV) but may have superimposed bacterial infection (strep pneumo, m cat, H flu)

Bacterial - URI symptoms 10-14 days w/o improvement OR severe symptoms of high fever and purulent drainage for 3 days

Question 5

Differential for Sinusitis

Answer 5

foreign body in nose

URI

allergic rhinitis

Question 6

Tx Bacterial Sinusitis

Answer 6

amoxicillin or cephalosporins for 14-21 days

Question 7

Herpangina

Answer 7

Hand-Foot-Mouth (Herpangina)

• Viruses - coxsackie, enteroviruses
• High fever and sore throat –> vesicles on pharynx/ soft palate / tonsils –> ulcers
  (v. Herpes which is more widespread in mouth like gums)

Question 8

Scarlet Fever

Answer 8

Strep Throat + sand paper rash (esp on butt)

Question 9

Complications of Strep Pharyngitis

Answer 9

• Glomerulonephritis (hematuria, edema, low C3 and hypertension 10 days after); not prevented by antibiotic use
• Peri-tonsillar or retropharyngeal abscesses (are they having trouble turning neck both ways?)
• Rheumatic fever (occurs 3 wks after) - JONES criteria; use antibiotics, anti-inflammation drugs and manage any heart symptoms

Question 10

Mononucleosis

Answer 10

• Present w/ severe pharyngitis, lymphadenopathy, fatigue and fever (sore throat goes away but fatigue may persist for weeks)
• Mucosal contact
• Dx
  
  • Heterophile antibody test (may be neg in young kids)
  • Atypical lymphocytes
• Tx - self limited; just limit contact sports due to splenomegaly

Question 11

Croup Presentation and Tx

Answer 11

PRESENTS WITH

• Upper airway obstruction - inspiration stridor
  
  • Seal like barking cough
  • Prodrome of fever and rhonorrhea for 12-24 hours before
  • Retractions, nasal flaring as airway become compromised
  • Inflammation of laryngotracheal tissues (v. Epiglossitis which is life threatening)
  • Steeple sign from narrow subglottic airway on imaging of chest
• Tx - supportive (nebulizer, humidifier), if bad then may need to support airway, maybe steroids

Question 12

Epiglossitis

Answer 12

• Seen in 3-5 yr olds in winter
• Emergency - need intubation before airway becomes completely obstructed
• Presentation - drooling, thumb print sign on chest X-ray, look toxic, lean forward to breath

Question 13

RSV Bronchiolitis

Answer 13

• Fever, cough, rhinorrhea and respiratory distress
• May have rhonchi or crackles
• Hypoxia if severe
• Tx - may need to hospitalize infants; supportive treatment w/ hydration and oxygen (apnea is common complication esp in young infants)

Question 14

Pavilizumab

Answer 14

IM monoclonal antibody for certain babies < 2 yo who may be at risk for severe RSV infection (heart or lung problems, premature)

Question 15

Pertussis

Answer 15

(whooping cough)

• 1-2 wk incubation period w/ low grade fever, cough and coryza
• 2-6 wks intense coughing spasms (emesis and petechiae from force) - spreads by droplets during coughing fits
• Tx
  
  • May hospitalize infants for support of cyanosis
  • Antibiotics in initial 1-2 wks before cough can shorten length of disease; give erythromycin or azithromycin
  • NO antibiotics once coughing
  • Protect contacts

Question 16

Pneumonia Etiology by Age

Answer 16

• Neonate - Group B strep, E. coli (vaginal canal), H flu, Listeria, CMV
• 1-6 mo - strep pneumo, staph aureus, m catarhallis, H flu, chlamydia trochamatis
• 6 mo to 5 yr - strep pneumo, m cat, h flu, staph aureus
• School aged - mycoplasma and chlamydia pneumonia most common (viral) then strep pneumonia

Question 17

Causes of Meningitis

Answer 17

• Viral > bacterial
• Viral - enterovirus
• Bacterial - strep pneumo, neisseria meningitis, Lyme
• In infants < 1 mo - Listeria, group B strep, E Coli, HSV
• Incidence of Hib has greatly decreased due to vaccine

Question 18

Kernig and Brudzinski Signs

Answer 18

• Kernig Sign - pain when move from flexing leg to extending leg
• Brudzinski Sign - when pt automatically flexes leg in response to bending their neck

Question 19

How do you diagnose meningitis?

Answer 19

• Dx - want to do CT or MRI if having neuro symptoms first; then do LP and analyze CSF; may do viral PCR for herpes and others
• CSF
• Viral - WBC < 500, lower neutrophils <50% and normal glucose / protein
• Bacterial - high WBC, high neutrophils, high protein and low glucose
• Lyme - <100 WBC, <30% neutrophils and normal glucose/protein

Question 20

How do you treat pinworm?

Answer 20

• albendazole, mebendazole or pyrantel pamoate 1X then repeat in 2 wks (treat household contacts)

Question 21

Rocky Mt Spotted Fever

Answer 21

• Tick bite –> spreads via lymphatics and blood vessels –> replicates in endothelial cells –> thrombosis and vasculitis w/ increased permeability
• Esp in April thru September in South Atlantic states
• Presentation = Fever, chills, malaise, headache, arthralgias 7 days after tick bite then rash appears 2-5 days in (maculopapular blanching red rash to petechiae that starts on wrists then moves proximally)
• Dx
  
  • Clinical because antibodies do not develop until 10 days after symptoms
  • May have hyponatremia and thrombocytopenia (not reliable)
• Diff
  
  • Looks exactly like erlilchiosis (also tick-borne) and meningiococcus maculopapular rash so start antibiotics against Neisseria if no history of tick bite
• Tx - doxycycline; add ceftriaxone if suspect meningitis

Question 22

Lyme Disease

Answer 22

• Eastern states (New England, NJ, PA, NY, etc) in April thru October
• Deer tick must attach for > 48 hrs to transmit
• Presentation
  
  • Erythema migrans (bulls eye) at bite site in 3-30 days
  • May be accompanied by myalgias, fever, malaise, headache
  • Early dissemination in days to weeks - multiple target lesions, heart block, cranial nerve palsy, meningitis
  • Late - usually > 6 wks after bite present w/ arthritis (usually in 1 knee)
• Dx - mainly clinical diagnosis
  
  • ELISA has high false positive rate
  • IgM titers take several weeks to increase
• Tx
  
  • Early - oral amoxicillin or cefuroxime In younger kids and doxycycline in kids > 8 yo

Question 23

HUS

Answer 23

hemolytic anemia, thrombocytopenia, nephropathy

occurs after shigella or EHEC

Question 24

Tularemia

Answer 24

• lone star tick
• regional tender adenopathy; may even have ulcerative LN’s
• IV gentamicin for 7 days

Question 25

Babesiosis

Answer 25

- Ixodes tick (NW US) - infects RBCs which can lead to hemolysis and acute renal failure BUT many cases asymptomatic - Tx = Quinine + clindamycin for 7+ days (usually do not require tx unless splenic dysfunction)

Question 26

STARI

Answer 26

(southern tick associated rash illness) - lone star tick; erythema migrans + fever + constitutional sx - Presents like Lyme but in S central US (diff area) - Tx is same as Lyme - doxycycline 14-21 days unless < 8 yo (amoxicillin or cefuroxime)

Question 27

PreSeptal v. Orbital Cellulitis

Answer 27

Pre-Septal * Infection of anterior eyelid NOT orbit itself (spares ocular muscles) * Eyelid edema, erythema, warmth, tenderness +/- fever * Tx - oral antibiotics including CA MRSA coverage (clindamycin) Orbital * Bacterial infection of orbit posterior to orbital septum * Often a complication of acute or chronic sinusitis * Also eyelid edema, erythema, warmth, tenderness +/- fever * BUT w/ dec eye movement, proptosis, decreased vision and papilledema, pain w/ eye movements * Tx - admission w/ IV abx (similar - clindamycine or amp-sulbactam); may drain if severe **Can distinguish between them via CT of orbit

Question 28

What are the indications for renal US or VCUS in kids?

Answer 28

RENAL US * < 2 yo * Poor response to abx * Recurrent febrile UTI * HTN * Family hx of renal or urological abnormalities VCUS (voiding cystourethrogram) - detects VUR * Multiple UTIs * Family hx abnormalities * HTN * Poor growth * Unusual pathogen * Abnormal finding on renal US

Question 29

How do you decide when to switch from IV to PO abx in septic arthritis or osteomyelitis?

Answer 29

* Once pt shows clinical improvement | * Guided by serial CRP measurements; want to see decline in CRP

Question 30

HIV Tx in Infants (3 options)

Answer 30

* Zidovudine 6 wks * OR 3 doses nevirapine then 6 wks zidovudine * OR 2 wks nelfinavir and lamivudine then 6 wks zidovudine (AZT)

Question 31

Toxic Shock Syndrome (presentation, dx, tx)

Answer 31

* Presentation - fever + sun burn like rash (desquamation) + hypotension + end-organ damage * Must have involvement of 3+ organs * GI - vomiting or diarrhea * Muscle - CPK 2X ULN or severe myalgia * Mucous membrane hyperemia * Renal - Cr 2X ULN * Hepatic - LFTs 2X ULN * CNS - altered mental status * Thrombocytopenia < 100,000 * Throat cx, CSF cx and blood cx should be negative (rule out other sources) * Tx - fluid and BP support; remove tampons or drain any assesses (remove source); IV vancomycin or clindamycin

Question 32

Shunt Infection (pathophysiology, presentation, dx, tx)

Answer 32

CAUSES - Proximal infection (in ventricle) - colonization during placement - Distal infection (peritoneum) - hematogenous seeding or colonization w/ bowel flora * May lead to obstruction of shunt itself from the inflammation --> sx consistent w/ inc ICP (headache, vomiting, lethargy) * Cushing Triad - HTN, bradycardia, abnormal respiratory pattern (means in ICP) * "Shampoo Sign" - compressing shunt at ventricle releases more bacteria into bloodstream causing fever and chills (as in when rubbing in shampoo) * Dx - pos blood cx, CSF cx (from shunt NOT LP) or inc CSF WBCs + one of the following ... * Fever, peritonitis signs, neuro sx or evidence of shunt malfunction * May get head CT or Xray shunt series (from skull - chest - abdomen) to look for kinks or discontinuity * Tx - remove shunt (external replacement if needed), IV abx, then get daily CSF gram stain and culture and can replaced shunt after CSF cultures neg for 7-14 days

Question 33

What is the definition of FUO? What is the work-up in infants?

Answer 33

DEFINITION > 100.4 (rectal in infants) for 8+ days and no apparent source after initial evaluation WORK UP * CBC w/ diff * Blood cx * Urine cx and UA * LP w/ CSF stain, culture, differential, glucose, protein, maybe HSV PCR * CXR - esp if resp symptoms * Low threshold for HSV in infants < 21 days

Question 34

HACEK Organisms

Answer 34

Infective Endocarditis * Haemophilus parainfluenza * Aggregatibacter * Cardiobacterium hominis * Eikenella corrodens * Kingella kingae