[Dapsone-induced methaemoglobinaemia].

Dapsone is used as an antibiotic for dermatological disorders and may cause methaemoglobinaemia. Specific treatment with intravenous methylene blue is the treatment of choice. We present a case of dapsone-induced methaemoglobinaemia. Arterial blood gas analysis showed that pH was 7.4, PaO2 11.7 kPa, PaCO2 4.5 kPa and bicarbonate concentration 21.9 mmol/l. The methaemoglobin level was found to be 32%. The symptoms were headache and tachycardia. Methylene blue was administered and the methaemoglobin level dropped to 5% within three days.