COMAT Pediatrics Exam V3 | COMAT Pediatrics |
Q&A with Rationale (COMAT Pediatrics Exam) |
National Board of Osteopathic Medical Examiners
(NBOME)
1. A 3-week-old male presents with non-bilious, projectile vomiting after every feeding. On
physical examination, a small, firm, mobile mass is palpated in the right upper quadrant.
Which of the following is the most likely metabolic abnormality expected in this patient?
A. Hypochloremic, hypokalemic metabolic alkalosis
B. Hyperchloremic metabolic acidosis
C. Hyperkalemic metabolic acidosis
D. Normal anion gap metabolic acidosis
Correct Answer: A
Explanation: Infantile hypertrophic pyloric stenosis leads to the loss of gastric
hydrochloric acid and potassium through persistent vomiting. The kidney attempts to
compensate by retaining hydrogen ions at the expense of potassium, leading to the classic
metabolic profile. Recognizing this pattern is crucial for pre-operative stabilization and
fluid resuscitation.
,2. A 4-year-old girl is brought to the clinic with a low-grade fever and a bright red rash on her
cheeks that looks like she was slapped. A few days later, a lace-like erythematous rash
appears on her trunk and extremities. Which of the following is the most likely causative
agent?
A. Human Herpesvirus 6
B. Coxsackievirus A16
C. Parvovirus B19
D. Group A Streptococcus
Correct Answer: C
Explanation: Erythema infectiosum, also known as fifth disease, is caused by Parvovirus
B19 and typically presents with the classic slapped-cheek rash followed by a reticular
pattern. While usually benign in children, it can cause transient aplastic crisis in patients
with chronic hemolytic anemias like sickle cell disease. Understanding the clinical
progression helps in reassuring parents and identifying at-risk populations.
3. An 18-month-old male is brought to the emergency department due to a sudden onset of
barking cough and inspiratory stridor that worsens at night. He has no history of drooling or
difficulty swallowing. Which of the following is the most appropriate initial treatment?
A. Inhaled albuterol
B. Intravenous antibiotics
C. Oral or intramuscular dexamethasone
,D. Immediate endotracheal intubation
Correct Answer: C
Explanation: Laryngotracheobronchitis, or croup, is characterized by subglottic narrowing
and classic respiratory sounds. Corticosteroids like dexamethasone are the mainstay of
treatment for mild to moderate cases to reduce airway edema. Clinical judgment is
required to differentiate croup from more severe conditions like epiglottitis which would
present with high fever and drooling.
4. A 2-year-old boy presents with a 2-day history of intermittent abdominal pain and ‘currant
jelly’ stools. During episodes, he draws his knees to his chest and screams. On examination, a
sausage-shaped mass is felt in the right abdomen. What is the best initial diagnostic and
therapeutic step?
A. Air or contrast enema
B. Surgical laparotomy
C. Abdominal CT scan
D. Upper GI series
Correct Answer: A
Explanation: Intussusception is the most common cause of intestinal obstruction in
children aged 6 to 36 months. An air or hydrostatic enema serves as both the definitive
diagnostic test and the primary treatment modality by reducing the telescoped bowel.
, Failure of non-surgical reduction or signs of peritonitis necessitates immediate surgical
intervention.
5. A 10-year-old male with a history of sickle cell disease presents with acute onset of chest
pain, fever, and tachypnea. A chest X-ray shows a new pulmonary infiltrate in the left lower
lobe. What is the most appropriate next step in management?
A. Start aggressive fluid resuscitation and IV ibuprofen
B. Observe for 24 hours without intervention
C. Perform an emergent bone marrow biopsy
D. Administer supplemental oxygen, IV antibiotics, and pain management
Correct Answer: D
Explanation: Acute Chest Syndrome is a leading cause of mortality in sickle cell patients
and requires rapid recognition. Management includes broad-spectrum antibiotics
(covering Mycoplasma and Pneumococcus), oxygen therapy, and careful fluid balance to
prevent pulmonary edema. Osteopathic considerations would involve monitoring for
viscerosomatic changes in the T2-T7 region.
6. A 6-year-old girl is brought to the pediatrician for a routine check-up. Her parents are
concerned that she is shorter than her peers. Her bone age is determined to be 4 years, while
her chronological age is 6 years. Her growth velocity is normal. What is the most likely
diagnosis?
A. Growth hormone deficiency
Q&A with Rationale (COMAT Pediatrics Exam) |
National Board of Osteopathic Medical Examiners
(NBOME)
1. A 3-week-old male presents with non-bilious, projectile vomiting after every feeding. On
physical examination, a small, firm, mobile mass is palpated in the right upper quadrant.
Which of the following is the most likely metabolic abnormality expected in this patient?
A. Hypochloremic, hypokalemic metabolic alkalosis
B. Hyperchloremic metabolic acidosis
C. Hyperkalemic metabolic acidosis
D. Normal anion gap metabolic acidosis
Correct Answer: A
Explanation: Infantile hypertrophic pyloric stenosis leads to the loss of gastric
hydrochloric acid and potassium through persistent vomiting. The kidney attempts to
compensate by retaining hydrogen ions at the expense of potassium, leading to the classic
metabolic profile. Recognizing this pattern is crucial for pre-operative stabilization and
fluid resuscitation.
,2. A 4-year-old girl is brought to the clinic with a low-grade fever and a bright red rash on her
cheeks that looks like she was slapped. A few days later, a lace-like erythematous rash
appears on her trunk and extremities. Which of the following is the most likely causative
agent?
A. Human Herpesvirus 6
B. Coxsackievirus A16
C. Parvovirus B19
D. Group A Streptococcus
Correct Answer: C
Explanation: Erythema infectiosum, also known as fifth disease, is caused by Parvovirus
B19 and typically presents with the classic slapped-cheek rash followed by a reticular
pattern. While usually benign in children, it can cause transient aplastic crisis in patients
with chronic hemolytic anemias like sickle cell disease. Understanding the clinical
progression helps in reassuring parents and identifying at-risk populations.
3. An 18-month-old male is brought to the emergency department due to a sudden onset of
barking cough and inspiratory stridor that worsens at night. He has no history of drooling or
difficulty swallowing. Which of the following is the most appropriate initial treatment?
A. Inhaled albuterol
B. Intravenous antibiotics
C. Oral or intramuscular dexamethasone
,D. Immediate endotracheal intubation
Correct Answer: C
Explanation: Laryngotracheobronchitis, or croup, is characterized by subglottic narrowing
and classic respiratory sounds. Corticosteroids like dexamethasone are the mainstay of
treatment for mild to moderate cases to reduce airway edema. Clinical judgment is
required to differentiate croup from more severe conditions like epiglottitis which would
present with high fever and drooling.
4. A 2-year-old boy presents with a 2-day history of intermittent abdominal pain and ‘currant
jelly’ stools. During episodes, he draws his knees to his chest and screams. On examination, a
sausage-shaped mass is felt in the right abdomen. What is the best initial diagnostic and
therapeutic step?
A. Air or contrast enema
B. Surgical laparotomy
C. Abdominal CT scan
D. Upper GI series
Correct Answer: A
Explanation: Intussusception is the most common cause of intestinal obstruction in
children aged 6 to 36 months. An air or hydrostatic enema serves as both the definitive
diagnostic test and the primary treatment modality by reducing the telescoped bowel.
, Failure of non-surgical reduction or signs of peritonitis necessitates immediate surgical
intervention.
5. A 10-year-old male with a history of sickle cell disease presents with acute onset of chest
pain, fever, and tachypnea. A chest X-ray shows a new pulmonary infiltrate in the left lower
lobe. What is the most appropriate next step in management?
A. Start aggressive fluid resuscitation and IV ibuprofen
B. Observe for 24 hours without intervention
C. Perform an emergent bone marrow biopsy
D. Administer supplemental oxygen, IV antibiotics, and pain management
Correct Answer: D
Explanation: Acute Chest Syndrome is a leading cause of mortality in sickle cell patients
and requires rapid recognition. Management includes broad-spectrum antibiotics
(covering Mycoplasma and Pneumococcus), oxygen therapy, and careful fluid balance to
prevent pulmonary edema. Osteopathic considerations would involve monitoring for
viscerosomatic changes in the T2-T7 region.
6. A 6-year-old girl is brought to the pediatrician for a routine check-up. Her parents are
concerned that she is shorter than her peers. Her bone age is determined to be 4 years, while
her chronological age is 6 years. Her growth velocity is normal. What is the most likely
diagnosis?
A. Growth hormone deficiency
