Methemoglobinemia with hemolytic anaemia as a result of acute dapsone intoxication

We describe a case of methemoglobinemia byacute dapsone intoxication in a 24-year-old female who ingested 20 tablets of Dapsone 100mg. The patient was admitted to the Medicine Emergency and Trauma Centre (METC) at King George's Medical University, Lucknow. On presentation, she exhibited respiratory distress, restlessness, altered behavior, and cyanosis of the lips and fingertips. Arterial blood gas analysis revealed dark brown colored blood with abnormal parameters, including a pH of 7.481, methemoglobin level of 26.6%, and a low oxygen saturation level. Gastric lavage was performed in the casualty department, and the patient was subsequently transferred to the Intensive Care Unit. Treatment involved administration of Methylene Blue and supportive care with supplemental oxygen and ascorbic acid and Vitamin E supplementation. The patient's methemoglobin levels gradually decreased, indicating a response to treatment. Laboratory investigations also revealed evidence of concurrent haemolytic anemia. Patient demonstrated improved respiratory distress and behavior by the treatment.