This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
A child develops non-blanching Macules and papules on lower extremities, mild abdominal pain and skin biopsy showed IgA deposition. Most appropriate diagnosis is – 
Select and explain. 
A. Drug induced vasculitis, B. HSP, C. Wegener's granulomatosis, D. Kawasaki disease
B: HSP
Answer: B: HSP 
Explanation: H.S. purpura is characterized by a tetrad of
Purpura,
Arthritis,
Glomerulonephritis and
Abdominal pain.

Diagnosis of H.S.purpura

Diagnosis is based on signs and symptoms.
Skin biopsy demonstrates leukocytoclastic vasculitis with IgA and C3 deposition.
Renal biopsy demonstrates IgA in mesangium.