Pemphigus-like lesions induced by imiquimod

Imiquimod is an immunomodifier recently approved for the treatment of superficial basal cell carcinomas (sBCC). Although local adverse events (AEs) are the most commonly reported, systemic AEs have also been described. We present the case of a 60-year-old woman who, after the application of two sachets of imiquimod cream per day for 5 days/week to two large sBCCs, developed pemphigus-like lesions both at and distant from the application site. Histological examination of a skin biopsy found intraepidermal acantholytic blistering but results of direct immunofluorescence examination were negative. The lesions resolved after cessation of imiquimod. Two previous cases of imiquimod-induced pemphigus have been reported, but this is the first case with lesions distant from the site of application. We suggest that systemic absorption of the drug or greatly increased synthesis of cytokines could explain this reaction and recommend the use of low doses of imiquimod in the treatment of large or multiple sBCCs.