Warfarin-Induced Skin Necrosis
A 62-year-old woman was referred for skin necrosis on the lateral aspect of the right thigh (), 12 days after admission for refractory atrial fibrillation secondary to mitral valve stenosis and insufficiency. Her ventricular rate had been controlled by isoprolol and the patient had been started immediately on 5 mg warfarin per day without simultaneous administration of heparin. On day 4, she developed painful ecchymosis of the lateral surface of the right thigh, initially misinterpreted as a hematoma, and the warfarin was reduced to 2 mg daily. On day 6, skin necrosis with eschar formation developed, and warfarin therapy was resumed to 1 mg per day. On day 12, the patient presented with a full thickness cutaneous necrosis. A laboratory workup indicated a normal clotting profile (). A histopathologic examination of incisional cutaneous biopsy was suggestive of warfarin-induced skin necrosis ().\nAccordingly, warfarin was discontinued and intravenous unfractionated heparin therapy was initiated. As the patient refused surgery, conservative autolytic debridement with hydrogel and hydrocolloid dressings was achieved, and the cutaneous deficit was healed by secondary intention. Unfractionated heparin was replaced with low-molecular weight (LMW) heparin for 17 days. Subsequently, warfarin was re-introduced at a daily dose of 2 mg with continuation of heparin, until international normalized ratio (INR) was within the therapeutic range. The cutaneous lesion healed with a scar and the patient developed no further skin necrosis during 15 months of follow-up.