Dermatomyositis after interferon alpha treatment

An association between auto-immune disorders and interferon (IFN) has been reported. High levels of natural IFNα are present in the blood of patients with auto-immune disease and correlate with disease activity. In addition, IFNα treatment of humans has resulted in multiple reports of associatied auto-immune phenomena. We describe a patient who underwent resection of regionally metastatic melanoma, was given adjuvant high-dose IFNα2b, and subsequently developed dermatomyositis. To the author's knowledge this is the first report of dermatomyositis in association with IFNα treatment. We review the literature reporting associations between IFNα and auto-immune disease and discuss possible mechanisms by which IFNα may contribute to the development of auto-immune disease. High dose IFNα2b is more commonly prescribed since it was approved as an adjuvant treatment for patients with surgically resected high-risk melanoma. The potential for cases of IFN-associated autoimmune disease is therefore a clinical concern. Standard side effects of high-dose IFN therapy resemble symptoms of auto-immune diseases, which may make prompt diagnosis difficult. Therefore, it is important that auto-immune diseases such as dermatomyositis are recognized as potential side effects of treatment with high-dose IFNα.