Warfarin skin necrosis associated with protein S deficiency and a mutation in the methylenetetrahydrofolate reductase gene

Summary The use of warfarin is rarely complicated by skin necrosis. We describe a 50‐year‐old woman who presented with a left leg deep venous thrombosis and subsequent pulmonary embolism. She was initially anticoagulated with low‐molecular weight heparin and subsequently warfarin. Within 4 days abdominal skin necrosis developed. Investigations revealed the presence of protein S deficiency and in addition, a mutation in the methylenetetrahydrofolate reductase gene ( MTHFR ). We present, to our best knowledge, the first case of warfarin skin necrosis associated with a methylenetetrahydrofolate reductase mutation.