Bullous eruption with circulating pemphigus-like antibodies following interferon-alpha therapy.

Two patients with classic Kaposi sarcoma developed bullous lesions and pemphigus-like 'anti-intercellular-substance' antibodies when treated with interferon-alpha (IFN-alpha). In one of them direct immunofluorescence was consistent with pemphigus/pemphigoid features. The immunoprecipitation test showed no specific bands. The mechanism by which IFN-alpha may induce the production of anti-intercellular-substance antibodies is discussed.