LATEST PEDIATRIC HOSPITAL MEDICINE
CERTIFICATION EXAM OFFERED BY
AMERICAN BOARD OF PEDIATRICS |
COMPLETE EXAM Q&A WITH RATIONALES
1. A 6-month-old infant presents with fever (39.5°C)
and irritability. Lumbar puncture reveals 500 WBC/μL
(90% neutrophils), glucose 20 mg/dL, protein 150
mg/dL. Gram stain shows gram-positive cocci in pairs
and chains. What is the most likely pathogen?
A) Group B Streptococcus (Streptococcus
agalactiae)
B) Streptococcus pneumoniae
C) Neisseria meningitidis
D) Listeria monocytogenes
Correct answer: A
Rationale: Group B Streptococcus (GBS) is a
common cause of bacterial meningitis in infants <3
months of age, especially if the mother is colonized.
S. pneumoniae (B) is more common after 2 months of
age. Listeria (D) 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. The child is sitting
upright, alert, with no drooling. What is the most
appropriate initial management?
A) Lateral neck radiograph
B) Direct laryngoscopy in the operating room
C) Dexamethasone (0.6 mg/kg orally or IM) and
supportive care
D) Intravenous antibiotics and racemic epinephrine
Correct answer: C
Rationale: Viral croup (laryngotracheobronchitis) is
treated with dexamethasone (oral or IM) to reduce
airway edema. Racemic epinephrine (D) is for
moderate-to-severe croup with respiratory distress.
Drooling suggests epiglottitis.
3. A 5-year-old child with a history of asthma presents
with a severe asthma exacerbation. Albuterol
nebulization (2.5 mg) and ipratropium bromide are
given. The child remains tachypneic (respiratory rate
40) and has a peak expiratory flow (PEF) of 45% of
predicted. What is the most appropriate next step?
A) Oral corticosteroids (prednisone 2 mg/kg, max 60
mg)
,B) Intravenous magnesium sulfate (50 mg/kg)
C) Intubation and mechanical ventilation
D) Inhaled corticosteroids (fluticasone) (not acute)
Correct answer: A
Rationale: Moderate asthma exacerbation (PEF 40-
69%) requires systemic corticosteroids (oral
prednisone or IV methylprednisolone). Magnesium
(B) is for severe exacerbation (PEF <40%)
unresponsive to initial therapy. Intubation (C) for
impending respiratory failure.
4. A 10-day-old infant presents with poor feeding,
lethargy, and vomiting. Serum electrolytes show
hyponatremia (Na 120 mEq/L), hyperkalemia (K+ 7.0
mEq/L), and hypoglycemia (glucose 30 mg/dL). What
is the most likely diagnosis?
A) Congenital adrenal hyperplasia (salt-wasting 21-
hydroxylase deficiency)
B) Pyloric stenosis (hypochloremic metabolic
alkalosis)
C) Sepsis (adrenal insufficiency)
D) Renal tubular acidosis
Correct answer: A
, Rationale: Salt-wasting CAH (21-hydroxylase
deficiency) presents with hyponatremia,
hyperkalemia, hypoglycemia, and vomiting in the first
2 weeks of life (males have no ambiguous genitalia,
females are virilized). 17-OHP is elevated.
5. A 3-year-old child presents with a 2-day history of
fever, cough, and respiratory distress. Chest X-ray
shows a round pneumonia (right lower lobe). The
child is fully vaccinated (PCV13, Hib). What is the
most likely pathogen?
A) Streptococcus pneumoniae (pneumococcus)
B) Mycoplasma pneumoniae
C) Staphylococcus aureus
D) Respiratory syncytial virus (RSV)
Correct answer: A
Rationale: Round pneumonia in children is classically
caused by Streptococcus pneumoniae
(pneumococcus). Despite vaccination, non-vaccine
serotypes can cause disease. Mycoplasma (B)
causes atypical pneumonia (interstitial pattern).
6. A 4-year-old child is admitted with bronchiolitis
(RSV positive) and respiratory distress. The child is
on high-flow nasal cannula (HFNC) at 10 L/min with
CERTIFICATION EXAM OFFERED BY
AMERICAN BOARD OF PEDIATRICS |
COMPLETE EXAM Q&A WITH RATIONALES
1. A 6-month-old infant presents with fever (39.5°C)
and irritability. Lumbar puncture reveals 500 WBC/μL
(90% neutrophils), glucose 20 mg/dL, protein 150
mg/dL. Gram stain shows gram-positive cocci in pairs
and chains. What is the most likely pathogen?
A) Group B Streptococcus (Streptococcus
agalactiae)
B) Streptococcus pneumoniae
C) Neisseria meningitidis
D) Listeria monocytogenes
Correct answer: A
Rationale: Group B Streptococcus (GBS) is a
common cause of bacterial meningitis in infants <3
months of age, especially if the mother is colonized.
S. pneumoniae (B) is more common after 2 months of
age. Listeria (D) 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. The child is sitting
upright, alert, with no drooling. What is the most
appropriate initial management?
A) Lateral neck radiograph
B) Direct laryngoscopy in the operating room
C) Dexamethasone (0.6 mg/kg orally or IM) and
supportive care
D) Intravenous antibiotics and racemic epinephrine
Correct answer: C
Rationale: Viral croup (laryngotracheobronchitis) is
treated with dexamethasone (oral or IM) to reduce
airway edema. Racemic epinephrine (D) is for
moderate-to-severe croup with respiratory distress.
Drooling suggests epiglottitis.
3. A 5-year-old child with a history of asthma presents
with a severe asthma exacerbation. Albuterol
nebulization (2.5 mg) and ipratropium bromide are
given. The child remains tachypneic (respiratory rate
40) and has a peak expiratory flow (PEF) of 45% of
predicted. What is the most appropriate next step?
A) Oral corticosteroids (prednisone 2 mg/kg, max 60
mg)
,B) Intravenous magnesium sulfate (50 mg/kg)
C) Intubation and mechanical ventilation
D) Inhaled corticosteroids (fluticasone) (not acute)
Correct answer: A
Rationale: Moderate asthma exacerbation (PEF 40-
69%) requires systemic corticosteroids (oral
prednisone or IV methylprednisolone). Magnesium
(B) is for severe exacerbation (PEF <40%)
unresponsive to initial therapy. Intubation (C) for
impending respiratory failure.
4. A 10-day-old infant presents with poor feeding,
lethargy, and vomiting. Serum electrolytes show
hyponatremia (Na 120 mEq/L), hyperkalemia (K+ 7.0
mEq/L), and hypoglycemia (glucose 30 mg/dL). What
is the most likely diagnosis?
A) Congenital adrenal hyperplasia (salt-wasting 21-
hydroxylase deficiency)
B) Pyloric stenosis (hypochloremic metabolic
alkalosis)
C) Sepsis (adrenal insufficiency)
D) Renal tubular acidosis
Correct answer: A
, Rationale: Salt-wasting CAH (21-hydroxylase
deficiency) presents with hyponatremia,
hyperkalemia, hypoglycemia, and vomiting in the first
2 weeks of life (males have no ambiguous genitalia,
females are virilized). 17-OHP is elevated.
5. A 3-year-old child presents with a 2-day history of
fever, cough, and respiratory distress. Chest X-ray
shows a round pneumonia (right lower lobe). The
child is fully vaccinated (PCV13, Hib). What is the
most likely pathogen?
A) Streptococcus pneumoniae (pneumococcus)
B) Mycoplasma pneumoniae
C) Staphylococcus aureus
D) Respiratory syncytial virus (RSV)
Correct answer: A
Rationale: Round pneumonia in children is classically
caused by Streptococcus pneumoniae
(pneumococcus). Despite vaccination, non-vaccine
serotypes can cause disease. Mycoplasma (B)
causes atypical pneumonia (interstitial pattern).
6. A 4-year-old child is admitted with bronchiolitis
(RSV positive) and respiratory distress. The child is
on high-flow nasal cannula (HFNC) at 10 L/min with
