Dermatology Online Journal

Henoch-Schönlein purpura (HSP) is a small vessel vasculitis characterized by the presence of vascular immunoglobulin A deposition that usually presents as non-thrombocytopenic palpable purpura. It primarily affects children and is less common in adults. The incidence of hemorrhagic necrotic skin lesions increases with age, similarly to renal involvement. Warfarin is a widely used oral anticoagulant drug that has rarely been associated with leukocytoclastic vasculitis and allergic interstitial nephritis. We report a patient with HSP who presented with cutaneous ulcerative plaques and proteinuria in the setting of warfarin therapy. We would like to raise the awareness of this potential adverse effect of warfarin for prompt diagnosis.