[Respiratory insufficiency caused by dapsone-induced methemoglobinemia]

We present a case of pneumonia and dapsone-induced methaemoglobinaemia. Methaemoglobinaemia leads to impaired delivery of oxygen to tissue. In our patient we observed that methaemoglobin interferes with the accuracy of pulse oximeter data. The patient was successfully treated with methylene blue, which converts methaemoglobin back to haemoglobin.