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Swollen, painful leg

A 54-year-old woman with diabetes was brought to the emergency department (ED) with a swollen right leg, fever, and altered mental status. The patient said that she’d had a pimple in the groin area 5 days earlier and had been experiencing increasing leg pain over the past few days. Her right leg was tender, red, and hot; large bullae were present. Her temperature was 102° F and her blood glucose level was 573 mg/dL. Her skin had a “woody” feel and an x-ray of her leg revealed gas in the muscles and soft tissue.

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The ED physician suspected necrotizing fasciitis (NF), a rapidly progressive infection of the deep fascia with necrosis of the subcutaneous tissues. It usually occurs after surgery or trauma. Patients have erythema and pain disproportionate to the physical findings.

This patient had type I NF, a polymicrobial infection with aerobic and anaerobic bacteria. It is frequently caused by enteric Gram-negative pathogens including Enterobacteriaceae organisms and Bacteroides. It can also occur with Gram-positive organisms such as non–group A streptococci and Peptostreptococcus.

Risk factors for type I NF include diabetes, severe peripheral vascular disease, obesity, alcoholism, cirrhosis, intravenous drug use, decubitus ulcers, poor nutritional status, surgery, and penetrating trauma. Early recognition based on signs and symptoms is potentially lifesaving. Although lab tests and imaging studies can confirm one’s clinical impression, rapid treatment with antibiotics and surgery are crucial to improving survival.

The patient in this case was taken to the operating room for debridement of her NF. Broad-spectrum antibiotics were started, but the infection continued to quickly advance. The patient died the following day. Her wound culture later grew Escherichia coli, Proteus vulgaris, Corynebacterium, Enterococcus, Staphylococcus sp., and Peptostreptococcus.

Adapted from: Dufel S, Martino M. Simple cellulitis or a more serious infection? J Fam Pract. 2006;55:396-400.

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