CorrespondenceErythema multiforme induced by imiquimod 5% cream Erythema multiforme (EM) is an acute self-limited immune-mediated reaction manifested by target skin lesions with mucous membrane involvement. Topical medication is considered a rare cause of EM and EM-like eruptions 1 . We report one patient with EM due to systemic reaction to imiquimod 5% cream.A 70-year-old man with a medical history of hypertension presented with multiple actinic keratoses on the scalp and nose. He was instructed to apply imiquimod cream 5% three times per week to his multiple actinic keratoses. A progressive local cutaneous reaction was observed at the application site of imiquimod accompanied by an intense flu-like syndrome during this treatment. On the third week of treatment, he also developed a symmetrically distributed eruption, with erythematous round maculopapules and bullae on the elbows, knees, palms, and soles (Fig. 1). Oral and ocular mucosae were not affected. A skin punch biopsy showed keratinocyte necrosis and intraepidermal vesiculation affecting the epidermis, accompanied by an inflammatory lymphohistiocytic infiltrate in the papillary dermis, all such findings being consistent with EM (Fig. 2). Treatment was discontinued, and the eruption resolved within two weeks. In this case, other well established causes of EM were ruled out; in particular, no evidence of herpes simplex infection and no past history of similar infection were observed, and no other drugs were introduced at that time. It was therefore assumed that the imiquimod induced the EM.A large number of topical medications 2,3 can induce EM and EM-like eruptions, including antibiotics, 4 nonsteroidal anti-inflammatory drugs, 5,6 corticosteroids, promethazine, balsam of Peru, econazole, pyrrolnitrin, vitamin E, nitroglycerin patch, ethylenediamine, mephenesin, and scopolamine ophthalmic drops. Serious systemic reactions