SummaryA 17-year-old woman presented painful recurrent ecchymoses. Identical lesions were specifically induced by injection of autologous leukocytic stroma. No evidence for possible immunological disturbances was found. Therapy with Nivaquine induced a complete and prolonged remission. The differential diagnosis of this rare form of non thrombocytopenic purpura, the autosensitization to D.N.A. or to leucocytic stroma, is discussed.