Heparin-induced skin necrosis associated with thrombocytopenia and acquired protein C and protein S deficiency

We have described a patient with colon cancer and liver metastases who developed heparin-induced thrombocytopenia and skin necrosis. We believe that the skin necrosis caused by the heparin/platelet factor 4 antibody was exacerbated by the acquired protein C and protein S deficiency. After the heparin was discontinued and infection treated, the skin necrosis and thrombocytopenia resolved. This case illustrates the fact that, in patients with heparin-induced skin necrosis, a search must be undertaken for an underlying pro-thrombotic state, which may precipitate the microthrombosis responsible for skin necrosis. We could not find any previous case reports of heparin-induced skin necrosis associated with isolated protein C deficiency, or combined protein C and protein S deficiency.