Chromoblastomycosis in a residual patch of leprosy

A middle aged male who had adequate dapsone monotherapy for borderline tuberculoid leprosy developed chromoblastomycosis within the residual analgesic patch during the post-treatment follow up period. Cladosporium carrionii, the causative fungus was isolated from culture in Sabouraud's agar. There was prompt therapeutic response to oral ketoconazole. The possible factors for development of chromoblastomycosis in this patient are discussed.