A 5-year-old boy presents with palpable purpuric rash over the buttocks and lower limbs, colicky abdominal pain, and knee swelling. Platelet count is 280 x 10^9/L and coagulation profile is normal. Skin biopsy shows leukocytoclastic vasculitis with IgA deposition. What is the most likely diagnosis?

• A Immune thrombocytopenic purpura
• B Henoch-Schonlein purpura (IgA vasculitis) ✓
• C Meningococcemia
• D Wegener granulomatosis (granulomatosis with polyangiitis)

Explanation

IgA vasculitis is a small vessel leukocytoclastic vasculitis with IgA immune complex deposition, classically causing palpable purpura dependent on the buttocks and legs, arthralgia, colicky abdominal pain, and nephritis. The key discriminator from ITP is that the platelet count is normal; ITP produces petechiae without vasculitic skin lesions. Meningococcemia causes toxic acral purpura with sepsis, not colicky pain with a well child between episodes.

Reference: Nelson Textbook of Pediatrics, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.