Severe skin necrosis following warfarin therapy in a patient with protein C deficiency.

A female patient with a history of both arterial and venous thrombosis developed extensive skin necrosis following warfarin treatment. When protein C deficiency was diagnosed, successful anticoagulation with warfarin was achieved by prolonging the course of intravenous heparin and introducing warfarin therapy with a low initial dose which was gradually increased. Aspects of the pathogenic mechanism are discussed.