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PEDIATRICS INFECTIOUS DISEASE
FINAL EXAM 2026|
150QS&AS|ALREADY GRADED A+
Q1. The most common cause of acute otitis media in children
under 2 years of age is:
A) Moraxella catarrhalis
B) Streptococcus pyogenes
C) Streptococcus pneumoniae
D) Haemophilus influenzae type b
Answer: C
Rationale: S. pneumoniae remains the leading pathogen, though H.
influenzae (non-typeable) and M. catarrhalis are also common.
Q2. A 4-year-old presents with fever, muffled voice, drooling,
and stridor. The most likely diagnosis is:
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A) Croup
B) Bacterial tracheitis
C) Epiglottitis
D) Peritonsillar abscess
Answer: C
Rationale: Drooling, muffled voice, and stridor in an unvaccinated
or partially vaccinated child suggest epiglottitis (Hib or other
pathogens).
Q3. Which antibiotic is first-line for empiric treatment of
suspected neonatal sepsis (0–7 days) in a full-term infant?
A) Ampicillin + gentamicin
B) Vancomycin + cefotaxime
C) Cefotaxime alone
D) Ampicillin + cefotaxime
Answer: A
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Rationale: Ampicillin covers Group B Strep and Listeria; gentamicin
covers Gram-negatives.
Q4. A child presents with a "bull's eye" rash after a tick bite.
The preferred outpatient therapy is:
A) Doxycycline for 28 days
B) Amoxicillin for 14 days (or doxycycline for 14 days if age
≥8)
C) Ceftriaxone IV
D) Azithromycin for 5 days
Answer: B
Rationale: Early localized Lyme disease: amoxicillin or doxycycline
for 14–21 days. Doxycycline avoided in <8 years unless necessary.
Q5. The classic "strawberry tongue" and desquamation of the
palms and soles are seen in:
A) Scarlet fever
B) Kawasaki disease
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C) Toxic shock syndrome
D) All of the above
Answer: D
Rationale: Strawberry tongue and desquamation occur in scarlet
fever (Group A Strep), Kawasaki disease, and staphylococcal TSS.
Q6. A 5-year-old with sickle cell disease presents with fever
and hip pain. The most likely pathogen is:
A) Streptococcus pneumoniae
B) Salmonella enterica
C) Staphylococcus aureus
D) E. coli
Answer: B
Rationale: Salmonella osteomyelitis is more common in sickle cell
patients, though S. aureus is still possible.
Q7. The most common cause of community-acquired
pneumonia in a fully immunized 3-year-old is:
PEDIATRICS INFECTIOUS DISEASE
FINAL EXAM 2026|
150QS&AS|ALREADY GRADED A+
Q1. The most common cause of acute otitis media in children
under 2 years of age is:
A) Moraxella catarrhalis
B) Streptococcus pyogenes
C) Streptococcus pneumoniae
D) Haemophilus influenzae type b
Answer: C
Rationale: S. pneumoniae remains the leading pathogen, though H.
influenzae (non-typeable) and M. catarrhalis are also common.
Q2. A 4-year-old presents with fever, muffled voice, drooling,
and stridor. The most likely diagnosis is:
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A) Croup
B) Bacterial tracheitis
C) Epiglottitis
D) Peritonsillar abscess
Answer: C
Rationale: Drooling, muffled voice, and stridor in an unvaccinated
or partially vaccinated child suggest epiglottitis (Hib or other
pathogens).
Q3. Which antibiotic is first-line for empiric treatment of
suspected neonatal sepsis (0–7 days) in a full-term infant?
A) Ampicillin + gentamicin
B) Vancomycin + cefotaxime
C) Cefotaxime alone
D) Ampicillin + cefotaxime
Answer: A
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Rationale: Ampicillin covers Group B Strep and Listeria; gentamicin
covers Gram-negatives.
Q4. A child presents with a "bull's eye" rash after a tick bite.
The preferred outpatient therapy is:
A) Doxycycline for 28 days
B) Amoxicillin for 14 days (or doxycycline for 14 days if age
≥8)
C) Ceftriaxone IV
D) Azithromycin for 5 days
Answer: B
Rationale: Early localized Lyme disease: amoxicillin or doxycycline
for 14–21 days. Doxycycline avoided in <8 years unless necessary.
Q5. The classic "strawberry tongue" and desquamation of the
palms and soles are seen in:
A) Scarlet fever
B) Kawasaki disease
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C) Toxic shock syndrome
D) All of the above
Answer: D
Rationale: Strawberry tongue and desquamation occur in scarlet
fever (Group A Strep), Kawasaki disease, and staphylococcal TSS.
Q6. A 5-year-old with sickle cell disease presents with fever
and hip pain. The most likely pathogen is:
A) Streptococcus pneumoniae
B) Salmonella enterica
C) Staphylococcus aureus
D) E. coli
Answer: B
Rationale: Salmonella osteomyelitis is more common in sickle cell
patients, though S. aureus is still possible.
Q7. The most common cause of community-acquired
pneumonia in a fully immunized 3-year-old is:
