Acquired Methemoglobinemia – A Case of Aniline Dye Exposure

Normal hemoglobin has HbA, which is seen in 95% of the normal population and that contains iron in reduced form i.e. Fe2+. When this hemoglobin undergoes oxidation, the ferrous form Fe2+ is converted to the ferric Fe3+ state and methemoglobin is produced. The ferric state in methemoglobin renders it unable to bind to oxygen and results in a leftward shift of the oxygenhemoglobin dissociation curve. Acquired methemoglobinemia is a rare but potentially fatal disorder. We report a case of acquired methemoglobinemia that was treated as ARDS with steroids and bronchodilator therapy.