Eczematous skin lesions induced by alpha interferon in atopic patients infected by hepatitis C virus: four cases.

Objectives. We report four cases of eczema induced by alpha interferon in a topic patients treated for chronic hepatitis C. Case reports. Eczema developed in 4 patients with certain (3 cases) or poss ible (1 case) atopy treated by subcutaneous injections of alpha interferon for hepatitis C virus infections. Delay to onset was 3 weeks to 6 months. I nterferon was highly likely the causal agent: lesions started at site of in terferon injection, followed the rhythm of interferon injections (three cas es), disappeared at interferon withdrawal. In two patients, the lesions dif fused to other sites. Both Introna(R) and Roferon(R) were used. Three patie nts also took ribavirine. The possible role of a contact factor (antiseptic ...) was ruled out. Skin tests (patch tests, prick tests, intradermal react ions) were negative for interferon alpha and for a standard battery. Discussion. The role of interferon in the induction of skin diseases or its influence on the course of certain dermatoses is well known. In atopic pat ients, interferon might induce eczema via an immunomodulator rather than an allergic mechanism since skin tests (performed in one patient) were negati ve. This observation is similar to that in psoriasis induced by interferon in predisposed subjects who develop skin lesions at injection sites which s ometimes diffuse to distant localizations. The role of other factors (hepat itis C virus infection, ribavirine) remains unknown; they might participate in this mechanism by aggravating skin dryness.