LATEST PEDIATRICS CERTIFICATION EXAM
OFFERED BY AMERICAN BOARD OF
PEDIATRICS (ABMS) | COMPLETE EXAM Q&A
WITH RATIONALES
1. A 6-month-old infant presents with fever (39.5°C),
irritability, and a bulging anterior fontanelle. Lumbar
puncture reveals 500 WBC/μL (90% neutrophils),
glucose 20 mg/dL (serum 90 mg/dL), and protein 150
mg/dL. Gram stain shows gram-positive cocci in pairs
and chains. What is the most likely pathogen?
A) Group B Streptococcus (GBS)
B) Streptococcus pneumoniae
C) Listeria monocytogenes
D) Escherichia coli
Correct answer: A
Rationale: In a 6-month-old, GBS is a common cause
of bacterial meningitis, especially if unvaccinated. S.
pneumoniae (B) is more common after 2 months of
age but GBS is still prevalent in infants. Listeria (C) is
seen in newborns and immunocompromised.
2. A 2-year-old child presents with acute onset of
stridor, barking cough, and low-grade fever.
,Symptoms are worse at night. On examination, the
child is sitting upright, alert, with no drooling. What is
the most appropriate next step?
A) Lateral neck radiograph
B) Direct laryngoscopy in the operating room
C) Corticosteroids (dexamethasone) and supportive
care
D) Intravenous antibiotics and racemic epinephrine
Correct answer: C
Rationale: This is viral croup
(laryngotracheobronchitis). Dexamethasone is first-
line treatment (reduces airway edema). Racemic
epinephrine (D) is for moderate to severe croup with
respiratory distress. Drooling suggests epiglottitis.
3. A 3-year-old child presents with fever, pharyngitis,
and a sandpaper-like rash on the trunk and
extremities. The rash spares the face. There is
circumoral pallor and Pastia lines (hyperpigmented
lines in skin folds). What is the most likely diagnosis?
A) Measles (rubeola)
B) Scarlet fever (Group A Streptococcus)
C) Kawasaki disease
D) Erythema infectiosum (fifth disease)
,Correct answer: B
Rationale: Scarlet fever (Group A Strep) presents
with sandpaper rash, circumoral pallor, strawberry
tongue, and Pastia lines. Caused by erythrogenic
toxin. Rapid strep test or throat culture is diagnostic.
4. A 4-week-old infant presents with poor feeding,
lethargy, and vomiting. On examination, the infant is
jaundiced and has hepatomegaly. Laboratory studies
show direct hyperbilirubinemia (conjugated 5 mg/dL,
total 12 mg/dL), elevated ALT (200 U/L), and
thrombocytopenia (50,000/μL). What is the most likely
diagnosis?
A) Biliary atresia
B) Neonatal hepatitis (viral)
C) Alagille syndrome
D) Galactosemia
Correct answer: D
Rationale: Galactosemia (autosomal recessive, GALT
deficiency) presents after milk ingestion with
jaundice, hepatomegaly, vomiting, lethargy, and E.
coli sepsis. Conjugated hyperbilirubinemia. Reducing
substances in urine. Biliary atresia (A) typically
presents later (2-8 weeks).
, 5. A 12-year-old girl presents with a 2-week history of
fever, rash, arthralgias, and headache. She has a
history of a recent sore throat. On examination, she
has a maculopapular rash on the trunk and
extremities, and mild hepatosplenomegaly.
Laboratory studies show elevated ESR and CRP, and
a positive antistreptolysin O (ASO) titer. What is the
most likely diagnosis?
A) Post-streptococcal reactive arthritis (PSRA)
B) Acute rheumatic fever (ARF)
C) Juvenile idiopathic arthritis (JIA)
D) Systemic lupus erythematosus (SLE)
Correct answer: A
Rationale: PSRA occurs after streptococcal infection,
with arthritis/arthralgias and other features, but
without major Jones criteria (carditis, chorea,
erythema marginatum, subcutaneous nodules). ARF
(B) requires two major or one major + two minor
criteria.
6. A 3-month-old infant presents with a history of
recurrent, severe, life-threatening infections
(pneumonia, meningitis, sepsis). Immunoglobulin
levels show very low IgG, IgA, IgM, and absent B cells
(CD19+). What is the most likely diagnosis?
OFFERED BY AMERICAN BOARD OF
PEDIATRICS (ABMS) | COMPLETE EXAM Q&A
WITH RATIONALES
1. A 6-month-old infant presents with fever (39.5°C),
irritability, and a bulging anterior fontanelle. Lumbar
puncture reveals 500 WBC/μL (90% neutrophils),
glucose 20 mg/dL (serum 90 mg/dL), and protein 150
mg/dL. Gram stain shows gram-positive cocci in pairs
and chains. What is the most likely pathogen?
A) Group B Streptococcus (GBS)
B) Streptococcus pneumoniae
C) Listeria monocytogenes
D) Escherichia coli
Correct answer: A
Rationale: In a 6-month-old, GBS is a common cause
of bacterial meningitis, especially if unvaccinated. S.
pneumoniae (B) is more common after 2 months of
age but GBS is still prevalent in infants. Listeria (C) is
seen in newborns and immunocompromised.
2. A 2-year-old child presents with acute onset of
stridor, barking cough, and low-grade fever.
,Symptoms are worse at night. On examination, the
child is sitting upright, alert, with no drooling. What is
the most appropriate next step?
A) Lateral neck radiograph
B) Direct laryngoscopy in the operating room
C) Corticosteroids (dexamethasone) and supportive
care
D) Intravenous antibiotics and racemic epinephrine
Correct answer: C
Rationale: This is viral croup
(laryngotracheobronchitis). Dexamethasone is first-
line treatment (reduces airway edema). Racemic
epinephrine (D) is for moderate to severe croup with
respiratory distress. Drooling suggests epiglottitis.
3. A 3-year-old child presents with fever, pharyngitis,
and a sandpaper-like rash on the trunk and
extremities. The rash spares the face. There is
circumoral pallor and Pastia lines (hyperpigmented
lines in skin folds). What is the most likely diagnosis?
A) Measles (rubeola)
B) Scarlet fever (Group A Streptococcus)
C) Kawasaki disease
D) Erythema infectiosum (fifth disease)
,Correct answer: B
Rationale: Scarlet fever (Group A Strep) presents
with sandpaper rash, circumoral pallor, strawberry
tongue, and Pastia lines. Caused by erythrogenic
toxin. Rapid strep test or throat culture is diagnostic.
4. A 4-week-old infant presents with poor feeding,
lethargy, and vomiting. On examination, the infant is
jaundiced and has hepatomegaly. Laboratory studies
show direct hyperbilirubinemia (conjugated 5 mg/dL,
total 12 mg/dL), elevated ALT (200 U/L), and
thrombocytopenia (50,000/μL). What is the most likely
diagnosis?
A) Biliary atresia
B) Neonatal hepatitis (viral)
C) Alagille syndrome
D) Galactosemia
Correct answer: D
Rationale: Galactosemia (autosomal recessive, GALT
deficiency) presents after milk ingestion with
jaundice, hepatomegaly, vomiting, lethargy, and E.
coli sepsis. Conjugated hyperbilirubinemia. Reducing
substances in urine. Biliary atresia (A) typically
presents later (2-8 weeks).
, 5. A 12-year-old girl presents with a 2-week history of
fever, rash, arthralgias, and headache. She has a
history of a recent sore throat. On examination, she
has a maculopapular rash on the trunk and
extremities, and mild hepatosplenomegaly.
Laboratory studies show elevated ESR and CRP, and
a positive antistreptolysin O (ASO) titer. What is the
most likely diagnosis?
A) Post-streptococcal reactive arthritis (PSRA)
B) Acute rheumatic fever (ARF)
C) Juvenile idiopathic arthritis (JIA)
D) Systemic lupus erythematosus (SLE)
Correct answer: A
Rationale: PSRA occurs after streptococcal infection,
with arthritis/arthralgias and other features, but
without major Jones criteria (carditis, chorea,
erythema marginatum, subcutaneous nodules). ARF
(B) requires two major or one major + two minor
criteria.
6. A 3-month-old infant presents with a history of
recurrent, severe, life-threatening infections
(pneumonia, meningitis, sepsis). Immunoglobulin
levels show very low IgG, IgA, IgM, and absent B cells
(CD19+). What is the most likely diagnosis?
