[Kaposi's disease: an unusual side-effect of topical corticosteroids].

BACKGROUND: Kaposi's sarcoma is an angiogenic tumour associated with HHV8 infection. There are several clinical forms, including those related to acquired immunosuppression. We report a case of nodular lesions in Kaposi's disease that appeared during treatment of bullous pemphigoid with topical corticosteroids. PATIENTS AND METHODS: A 74-year-old female patient presented bullous pemphigoid lesions on all four limbs that were treated with clobetasol cream, a topical corticosteroid. After 2 months of treatment, the patient noted the appearance of several asymptomatic purple, erythematous, papulonodular lesions of elastic consistency on her right thigh and both legs. The histological examination revealed Kaposi's disease with positive immunolabelling for HHV8 in the tumour cells. HIV serology was negative. The lesions disappeared 4 months after cessation of corticosteroid therapy and the patient was still in remission one year later. COMMENT: Authentic "Mediterranean" cutaneous Kaposi's disease was apparently revealed in this patient during treatment with extremely potent topical corticosteroids, before regressing completely on discontinuation of the medication. We discuss the various mechanisms that could have contributed to this side-effect of dermal corticosteroids, whose sustained application over a wide area caused HHV8 antigen reactivation.