A child with a history of cystic fibrosis appears with fever and increased coughing. Chest x-ray reveals a new infiltrate in the right lower lobe. Most likely diagnosis is:

Correct Answer: C

Rationale: Pneumonia fits fever, cough, and new infiltrate in cystic fibrosis, per CFF. A, B, D, E are less likely.

Correct Answer: C

Rationale: IV fluids and insulin treat diabetic ketoacidosis, per AAP (doc p150, Q595).

Correct Answer: A

Rationale: Bronchiolitis obliterans is a rare, chronic obstructive lung disease following severe lower respiratory infection. Adenovirus (Choice A) is the virus most commonly associated with this complication, particularly after severe bronchiolitis in young children, due to its propensity for persistent airway injury. Human metapneumovirus (Choice B), influenza (Choice C), and parainfluenza (Choice D) can cause bronchiolitis but are less frequently linked to bronchiolitis obliterans. Adenovirus’s strong association makes it the correct answer.

Correct Answer: B

Rationale: Anterior fontanel closes between 12-18 months B, per document 9.

Correct Answer: C

Rationale: Allergic bronchopulmonary aspergillosis fits Aspergillus in cystic fibrosis with respiratory symptoms, per CFF. A, B, D, E are less likely.

Correct Answer: B

Rationale: IBD features chronic pain, diarrhea, and occult blood, per AGA. A, C-E differ in chronicity.

Correct Answer: C

Rationale: Endoscopy (C) visualizes the upper GI tract (esophagus, stomach). Colonoscopy (A) and sigmoidoscopy (B) are lower GI, proctoscopy (D) is rectal. Document: 'Endoscopy is used to visualize the upper GI tract.'

Correct Answer: C

Rationale: The asthma triad includes aspirin intolerance, nasal polyps, and asthma (A, B, D) (ATS). Bronchiolitis is unrelated, and E is a trigger, not part of the triad.

Correct Answer: B

Rationale: Chickenpox features fever and vesicular rash, per CDC. A, C-E differ.