Mercer S and Wilson J
A 70 year oldgentleman who was admitted to hospital with flu-like symptoms, and later confirmed to be influenza A positive. His past medical history included Hairy Cell Leukaemia (HCL), hyperlipidaemia and hypertension. On review the patient was requiring 15L of oxygen via a non rebreathe mask, and despite this was still hypoxic. His ABG showed a significant discrepancy between SaO2 and PaO2 and an elevated methaemoglobin (MetHb) %. This was secondary to dapsone and was treated with Methylene Blue (MB) to good effect. This case report details this unusual condition in more detail.