Acute methaemoglobinaemia secondary to intentional dapsone overdose.

Methaemoglobinaemia is a rare but potentially life-threatening hemoglobinopathy. It is characterized by cyanosis that is not responsive to oxygen therapy. We report a case of acute methaemoglobinaemia secondary to intentional dapsone overdose. A 34 year old lady presented to our institution with a history of sudden onset of dyspnoea. Her level of consciousness had reportedly deteriorated dramatically during ambulance transportation and her Glasgow Coma Scale was 3/15 on arrival. She was normothermic and hemodynamically stable, but had a respiratory rate of 30 breaths per minute and was cyanosed with an SpO 2 of 83% on 15 litres of oxygen via a non-rebreather mask.