Getting the blues at a rock concert: a case of severe methaemoglobinaemia.

Methaemoglobin is the form of haemoglobin in which the iron moiety of the haem group has been oxidized from the ferrous to the ferric state. Methaemoglobinaemia is due to either an increase in the production of the oxidized haem moiety or due to decreased conversion back to the reduced form. This article presents a case of amyl nitrite-induced methaemoglobinaemia and discusses the diagnosis and treatment of this disorder.