Recombinant interferon (IFN)β is currently the most commonly prescribed treatment for long-term immunomodulation in multiple sclerosis, and is generally a well-tolerated treatment. Reactions to IFNβ at the injection site are a common side effect, ranging from the frequently observed transient erythema to a more severe cutaneous necrosis in 5% of patients.¹ We describe a patient presenting with panniculitis and subsequent lipoatrophy, secondary to IFNβ-1b treatment for multiple sclerosis. To our knowledge, this case is the first to show this syndrome in relation to IFNβ-1b injections.

A 37-year-old man with relapsing–remitting multiple sclerosis presented with a 5-day history of pain in the left thigh, diaphoresis and rigors. This had started 6 days after subcutaneously injecting IFNβ-1b (Betaferon, Schering, AG, Berlin, Germany), which he had been using for 27 months, at that site. He did not have arthralgia or myalgia. He had been diagnosed with multiple sclerosis 3 years earlier after an episode of transverse myelitis, and had had four relapses in the interim. Flu-like symptoms and mild reactions at the injection site had developed after initiation of IFNβ treatment, but had resolved spontaneously. He also had a diagnosis of migraine, for which he took sumatriptan and diclofenac. There was no history of drug allergies. He did not …