Necrotizing Fasciitis in a Patient on Long-Term Intramuscular Interferon-Beta for Multiple Sclerosis: A Case Report

Immunomodulatory injections are becoming common long-term treatments for neuromuscular diseases such as multiple sclerosis (MS), although they carry a risk of local site infection. We describe a case of a 57-year-old man who developed necrotizing fasciitis of the anterior thigh secondary to intramuscular (IM) injections of interferon-beta-1A for MS, ultimately developing septic shock and requiring serial debridements for source control.

This is the first reported case of necrotizing fasciitis from chronic IM injections for MS and deserves particular attention because of the immunosuppressive nature of the injections. In patients with underlying predisposing factors for infection, such as decubitus ulcers, it may be prudent to reconsider the administration route. Patients in hypermetabolic states should be closely monitored for impaired response to infections.