Dapsone dependent nodular panniculitis

A patient recorded to be suffering from tuberculoid leprosy since 1973 and on regular Dapsone monotherapy for about nine years developed asymmetrical, erythematous, subcutaneous, nodular swellings restricted chiefly to the extensor aspects of lower limbs two months after discontinuation of Dapsone therapy. During the course of Dapsone treatment, the patient had developed similar swellings twice previously each time when he stopped the drug for about a month. The swellings disappeared on commencement of Dapsone Treatment. This has been reconfirmed under our supervision. The biopsy of one of the lesions revealed panniculitis with vasculitis. The original diagnosis of leprosy was probably invalid.