[Muscular haematoma in Henoch-Schönlein purpura]

Henoch-Schonlein purpura is one of the most frequent systemic vasculitis in children. In adults, muscle involvement is extremely rare and not very well characterized. We report a case of Henoch-Schonlein purpura with severe skin and renal involvement in witch multiple intramuscular haematoma leaded to severe anaemia. Histological examination confirms the muscle localization of the disease.A 68 years old man treated by oral anticoagulation for multiple venous thrombosis, was admitted with necrotic vasculitis of the skin, abdominal pain and segmental IgA glomerulopathy. The diagnosis of Henoch-Schonlein purpura was rapidly made and intensive steroid therapy started. After rapid improvement, a haemorrhagic shock due to voluminous intramuscular haematoma was diagnosed by MRI. Histological examination of the muscle, confirms the localization of the disease.Intramuscular haematomas are very uncommon in Henoch-Schonlein purpura. There are usually a consequence of muscular immune complex vasculitis. In our patient, high dose corticosteroid was not unable to control the disease.