A 12-year-old presents with sneezing, clear rhinorrhea, and nasal itching... The most likely diagnosis is

Correct Answer: A

Rationale: The symptoms and physical findings (boggy, pale nasal edema with clear discharge) are classic for allergic rhinitis.

Correct Answer: C

Rationale: Bacterial sepsis is a common cause of sudden hypotension in VLBW infants due to systemic infection and inflammatory response. The other conditions can cause hypotension but are less likely to present suddenly.

Correct Answer: B

Rationale: Large VSDs typically present with symptoms like heart failure and failure to thrive within 1-3 months of age.

Correct Answer: C

Rationale: Mycoplasma pneumonia often presents with mild symptoms that do not correlate well with physical findings. It is known for a protracted course, low-grade fever, and a persistent cough. Antibiotics like macrolides are used for treatment, as penicillins are ineffective.

Correct Answer: A

Rationale: Respiratory distress syndrome (RDS) is the most common cause of perinatal mortality in preterm infants, caused by insufficient surfactant production leading to lung collapse and difficulty breathing.