[Necrotic toes in a female patient using interferon]

Interferon has an important role in treatment of viral hepatitis, multiple sclerosis and solid and non-solid tumours. Ischaemia and necrosis of the extremities are relatively little-known adverse effects of treatment with interferon.

A 44-year-old woman was treated with interferon-beta for relapsing-remitting multiple sclerosis. She developed ischaemia and necrosis of the right lower extremity. Extensive laboratory and imaging investigations offered no clear diagnosis, leading to suspicion of a connexion with interferon-beta treatment. Discontinuation of interferon lead to rapid healing, clearly suggesting a relationship between interferon and the vascular complications.

Vascular complications during treatment with interferon seem to arise fairly frequently, and can even occur many years after commencing therapy. When vascular symptoms similar to Raynaud's syndrome develop, careful monitoring of the disease course and treatment with vasodilators if required is important. If this is insufficiently effective, interferon should be discontinued. Prompt recognition can prevent significant morbidity in these patients.