Dapsone-induced agranulocytosis in patients with Hansen's disease*

How to cite this article: Contin LA, Rocha VB. Pseudo “fringe sign” in frontal fibrosing alopecia. An Bras Dermatol. 2017;92(6): 892-4. Dear Editor, Agranulocytosis induced by sulphonamide or dapsone (44-diaminodiphenylsulphone – DDS) is characterized by a low concentration or absence of granulocytes due to sulfone cytotoxicity effects on bone marrow and mononuclear cells.1 DDS is a structural analogue of para-aminobenzoic acid (PABA) that acts as a competitive inhibitor of the enzyme dihydropteroate synthase in the folate pathway. It has anti-inflammatory, antibacterial, antiprotozoal, and antifungal activities. Used since 1943 to treat leprosy, it is also indicated for the treatment of malaria, rheumatoid arthritis, granuloma annulare, dermatitis herpetiformis, and other vesiculobullous diseases. DDS adverse effects include hemolytic anemia, methemoglobinemia, gastritis, headache, agranulocytosis, hepatitis, peripheral neuropathy, nephrotic syndrome, dapsone syndrome, among others.1,2 DDS is part of the multidrug therapy (MDT) used to treat leprosy. The regimen is a combination of rifampicin (supervised monthly dose of 600mg) and dapsone (supervised monthly dose of 100mg and 100mg/daily) for paucibacillary patients, with the addition of clofazimine (supervised monthly dose of 300mg and 50mg/ daily) for multibacillar patients.2 We report a 61-year-old Caucasian female patient, resident in Juazeiro, state of Bahia, Brazil, complaining of a spot on the right elbow, which appeared 1 year before. Physical examination revealed a single hypochromic patch, approximately 1cm in diameter, with micropapular edges and absent thermal sensitivity. With a diagnosis of tuberculoid leprosy, we started a MDT regimen for paucibacillary leprosy. At day 14 after the first administration, the patient presented with adynamia, exertional dyspnea, normochromic normocytTania Rita Moreno de Oliveira Fernandes1,2 Bruno Nascimento de Jesus3 Tathyane Trajano Barreto3 Anderson de Almeida Pereira3 t Dapsone-induced agranulocytosis in patients with Hansen’s disease*