Beware of Warfarin-Induced Skin Necrosis in the Setting of Heparin-Induced Thrombocytopenia

Heparin-induced thrombocytopenia (HIT) and thrombosis affect a small minority of patients exposed to heparin. However, given the high proportion of patients who receive heparin during hospitalization, clinicians should be mindful to keep it on their differential. This case involves a 56-year-old woman who developed HIT during a prolonged hospitalization. She was started on a direct thrombin inhibitor, argatroban, until her platelets recovered, was bridged to warfarin, and later developed warfarin-induced skin necrosis (WISN). Patients with prolonged hospitalizations may have an inherent vitamin K deficiency, leading to erratic changes in international normalized ratio (INR). Currently, there are no guidelines to address very high supratherapeutic INR levels in this setting. Prompt diagnosis and close monitoring during treatment are essential to minimize the risk of morbidity and mortality.