Heparin skin necrosis--an important indicator of potentially fatal heparin hypersensitivity.

Skin necrosis at injection sites is a rare complication of heparin therapy. In this report, we describe only the second case of the even rarer complication of skin necrosis occurring at sites distant to those of subcutaneous heparin injections. The patient had also suffered systemic thrombotic events due to heparin-dependent platelet activation prior to the development of the skin necrosis, although these had not been recognized as such at the time. The development of heparin-induced skin necrosis should result in the immediate cessation of heparin therapy in order to prevent potentially fatal thrombotic events. This is in contrast to warfarin-induced skin necrosis, where therapy may be continued or restarted at a lower dose.