Warfarin-induced skin necrosis: a rare but catastrophic complication of warfarin

Abstract

Introduction Warfarin-induced skin necrosis is a rare but catastrophic complication of warfarin therapy, ranging in prevalence from 0.01% to 0.1%. This case report discusses a case of warfarininduced skin necrosis. Case report We report the case of an obese, 55-year-old woman who presented with extensive skin necrosis of the left lower limb on the fifth day of warfarin therapy and responded well with early diagnosis and treatment. Discussion Warfarin-induced skin necrosis is the result of a relatively hypercoagulable state produced by warfarin. Warfarin-induced skin necrosis typically occurs in obese, perimenopausal women of around 50 years of age with high loading doses of warfarin. Warfarin-induced skin necrosis typically involves skin and subcutaneous tissue overlying areas with significant adipose tissue, such as the breast, abdomen, thigh or buttocks. It presents within three to six days after beginning therapy. Conclusion Prevention and management of warfarin-induced skin necrosis in a timely manner should be emphasised to prevent permanent tissue damage. A more gradual approach using low initial dose and gradual increase in daily doses is believed to reduce the risk of warfarin-induced skin necrosis. Introduction Warfarin is a very commonly used anticoagulant in medical practice. Warfarin-induced skin necrosis (WISN) is a rare but catastrophic complication of warfarin therapy, ranging in prevalence from 0.01% to 0.1%1,2. Here, we report the case of a 55-year-old woman with WISN. Case report A 55-year-old woman was admitted to the hospital due to pain and swelling of her right leg. Her right lower limb was cold and right leg circumference was 8 cm more that the left one. Her vital parameters were in the normal range. Cardiovascular, respiratory and abdominal examination was normal. The patient had had a right hip fracture 35 days prior to presentation and was under conservative therapy at the time of presentation at our hospital. Colour Doppler ultrasound of the lower limb vessels revealed thrombosis in the right popliteal, superficial, deep and common femoral veins. Parenteral heparin and oral warfarin were started and coagulation tests were performed daily. Warfarin was initiated at a dose of 15 mg on the first day, 10 mg on the second day and 5 mg on the third day. On the third day, the international normalised ratio (INR) was in the normal range and parenteral heparin was discontinued. On the fifth day of warfarin therapy, the patient developed diffused, extremely painful, erythematous skin eruptions in the left lower limb. On the sixth day, the skin began to peel off and the condition progressed to an extensive lesion with severe skin necrosis of the left lower limb (Figure 1). Warfarin was discontinued and intravenous heparin was started. Vitamin K and fresh frozen plasma were also administered. Tests for factor V Leiden, lupus anticoagulant, anticardiolipin and antiphospholipid antibodies were negative. Surgical debridement of the necrotic area was performed and skin grafting was performed later. Finally, the patient was discharged after two months with a good general condition, on therapy with enoxaprin. * Corresponding author Email: dr.mahi1118@gmail.com 1 Department of Surgery, Vardhaman Mahavir Medical College and Safdarjung Hospital, New Delhi 110029, India Figure 1: Warfarin-induced extensive skin necrosis. De rm at ol og y