Henoch-Schönlein Purpura (HSP)

• Specific type of cutaneous small vessel vasculitis
• Presents with palpable purpura with predilection for lower extremities and buttocks; arthritis, hematuria, colicky abdominal pain, ± GI bleeding and vomiting
• Histology: leukocytoclastic vasculitis; DIF with perivascular IgA, C3 and fibrin
• Typically occurs after respiratory tract infection in children (much lower incidence in adults); 2% may develop permanent renal impairment
• Treatment: mainly supportive as typically self-limited