Among histological subtypes of classic Hodgkin disease, the most common one in children is:

Correct Answer: D

Rationale: Mixed cellularity Hodgkin lymphoma is the most common subtype in children and is associated with Epstein-Barr virus. It presents with widespread lymphadenopathy and systemic symptoms. Nodular sclerosis is more common in adolescents and young adults.

Correct Answer: C

Rationale: Dilute artificial formula can cause total body sodium depletion, leading to hyponatremia due to excessive water intake without adequate sodium replacement.

Correct Answer: C

Rationale: NSAIDs are common causes of fixed drug eruptions, which present as recurring skin lesions at the same site.

Correct Answer: C

Rationale: Digitalis (digoxin) is contraindicated in hypertrophic cardiomyopathy as it can increase left ventricular outflow obstruction.

Correct Answer: B

Rationale: Anaphylactoid purpura (Henoch-Schanlein purpura) is the most common cause of non-thrombocytopenic purpura in children, characterized by a small-vessel vasculitis leading to purpuric rash, arthritis, and renal involvement.