Skin necrosis: a rare complication of protein S deficiency.

Hereditary protein S deficiency is an autosomal dominant disorder leading to recurrent venous thrombosis and, less commonly, to arterial thrombosis. Cases of skin necrosis have been documented in patients with protein C or S deficiency while being treated with warfarin. We describe herein a patient with protein S deficiency who developed significant skin necrosis without being exposed to warfarin. She had a protracted clinical course resulting in gangrene and transmetatarsal amputation. Recognition of this rare complication and an earlyhematology referral may prevent dismal outcomes in patients with protein S deficiency.