Warfarin-Induced Skin Necrosis Despite Enoxaparin Bridging Therapy

Abstract

Skin necrosis is a rare albeit severe complication of warfarin use for anticoagulation, resulting in significant morbidity and mortality. Here, we present the case of a 58-year-old woman who developed erythema and pain in her left leg two weeks after initiation of warfarin therapy with concomitant early administration of heparin for a deep vein thrombosis and pulmonary embolism. Subsequently, the erythema progressed to skin necrosis, and a diagnosis of warfarin-induced skin necrosis (WISN) was suspected. Warfarin was discontinued, and unfractionated heparin was commenced. The simultaneous presence of eosinophilia pointed toward an associated drug-related hypersensitivity reaction. Dexamethasone was added to the medication regimen. The patient was discharged on a factor Xa inhibitor and prednisone. Recognizing WISN is crucial in patients receiving anticoagulation. The diagnosis can be particularly challenging in cases when bridging anticoagulation has been previously completed. Early diagnosis and drug discontinuation are critical to ensuring a favorable prognosis. Steroids may also play a role in the treatment of this condition if an associated drug hypersensitivity is identified.

Keywords: bridging anticoagulation; drug rash; drug-induced hypersensitivity; enoxaparin; warfarin therapy; warfarin-induced skin necrosis.

Figure 1. Early course of the left lower extremity erythema.

A: Initial hospital presentation. B: Day three of hospital presentation.

Figure 2. Erythema progression and macular rash development.

A: Left lower extremity day four. B: Right lower extremity day four.

Figure 3. Left lower extremity discoloration.

Figure 4. Left lower extremity rash improvement.