Dapsone-induced agranulocytosis presenting as neutropenic sepsis in borderline tuberculoid leprosy

Dapsone, a core component of multidrug therapy (MDT) for leprosy, can rarely cause life-threatening haematologic toxicity. We report a 66-year-old woman with borderline tuberculoid leprosy, receiving multibacillary MDT (MDT-MB), who developed fever, sore throat, and malaise seven days into her second monthly blister pack. Laboratory evaluation revealed severe neutropenia (absolute neutrophil count [ANC] 0.1 × 10⁹/L) and markedly elevated C-reactive protein (CRP 230 mg/L), consistent with dapsone-induced agranulocytosis. Neutropenic sepsis was clinically suspected. Peripheral blood smear showed haemolytic changes. Blood and urine cultures were sterile. 
Dapsone was immediately discontinued, and she received empiric intravenous cefuroxime, supportive care, and packed red blood cell transfusion for haemolysis-related anaemia. The fever resolved within 48 hours, and the ANC recovered over five days. Following complete haematologic recovery confirmed by periodic blood count monitoring, MDT-MB was resumed without dapsone, with continuation of rifampicin and clofazimine. This case underscores the importance of regular haematologic monitoring, early recognition, and prompt withdrawal of the offending agent. Timely supportive care and empiric antibiotics are essential to prevent potentially fatal complications.