Warfarin necrosis, also known as Coumadin necrosis, is a rare but serious complication of warfarin (Coumadin) therapy. Patients receiving loading doses of warfarin develop a transient hypercoagulable state resulting in thrombosis of small cutaneous vessels that eventuates in infarction and subsequent necrosis of the skin. If extensive, the condition can be fatal.

Approximately 1 of 10 000 patients who receive warfarin develop this reaction. Some patients have an associated protein C or protein S deficiency. Women are affected more often than men.

Once necrosis has occurred, the continued use of warfarin does not seem to cause additional lesions to develop. Lesions heal by granulation over weeks.