Prolonged treatment with interferon alpha and peginterferon induces rheumatoid arthritis syndrome and erythema nodosum.

The antiviral treatment of chronic C hepatitis has improved significantly over the past decade with the introduction of interferons (IFNs), and more recently, pegylated IFNs. Up to two-thirds of all patients treated with pegylated IFN combined with ribavirin can now achieve viral eradication if treated according to current guidelines. Despite this success rate, hematological, immunological, rheumatological and dermatological side effects have been reported in chronic hepatitis C patients treated with IFN-alpha. The subjects of this report are two young females with chronic hepatitis C, who developed rheumatoid syndrome and/or erythema nodosum during antiviral treatment with IFN-alpha or pegylated IFN combined with ribavirin.