Clinical Images

An Uncommon Cause of Skin Necrosis

Authors: Charles Bodine, MD and John Ragsdale, MD, MS

            A previously healthy 41-year-old woman presented to the hospital with abdominal distension. Further investigation resulted in a diagnosis of Budd-Chiari Syndrome. She was started on a heparin drip, which was stopped out of concern for heparin-induced thrombocytopenia (HIT), when her platelet count decreased from 541,000 to 57,000 over the course of ten days. However, her heparin platelet factor-4 (HPF-4) antibody testing was negative. She was then restarted on anticoagulation with low molecular weight heparin (LMWH). She received two days of injections in her right upper extremity, and developed pain, erythema, and ultimately skin necrosis at the injection site (See Figure 1). LMWH was abruptly stopped, and her skin findings improved dramatically.

While heparin-induced skin necrosis is a rare complication of LMWH (3,5,6) and the mechanism is not well understood, there are a few theories. This reaction is thought to be either immune-mediated intravascular thrombosis as in HIT (5), or a Type III immune complex-mediated hypersensitivity reaction (1,2). In this patient, the site of injection may have played a role, as fatty tissue tends to have poor blood circulation and be more prone to necrosis (2).

MCQ:

A 58-year-old obese man is diagnosed with acute DVT while undergoing treatment for pancreatitis in the hospital. His past medical history is significant for obesity, type II diabetes, and hypertension. He is initiated on intravenous unfractionated heparin for anticoagulation, and warfarin is begun two days later. Seven days after initiation of anticoagulation, he develops asymptomatic thrombocytopenia. His platelet count has decreased from 324 at admission to 76 over the last three days. His INR is 1.5. What is the next best step in management?

   a.   Change heparin from unfractionated to low molecular weight and continue warfarin.

   b.   Continue both heparin and warfarin.

   c.   Discontinue both heparin and warfarin. Start aspirin.

   d.   Discontinue heparin but continue warfarin.

   e.   Replace heparin with argatroban and continue warfarin.

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Dr. Bodine is a resident in Internal Medicine, University of Kentucky, Lexington, KY

Dr. Ragsdale is an assistant professor in the Division of Hospital Medicine, Department of Medicine, University of Kentucky, Lexington, KY.