Methemoglobinemia refers to the oxidation of ferrous iron (Fe++) to ferric iron (Fe+++) within the hemoglobin molecule.[1] This reaction impairs the ability of hemoglobin to transport oxygen and carbon dioxide, leading to tissue hypoxemia and in severe cases, death. Methemoglobinemia most commonly results from exposure to an oxidizing chemical, but may also arise from genetic, dietary, or even idiopathic etiologies.[2,3]

This case report describes the development of acquired methemoglobinemia in a 2 years old boy after accidental ingestion of Blue Detergent Dye , we are reporting this case because of these disparate causes, confusion may arise in the recognition and management of methemoglobinemia. Physicians may be aware of one etiology, such as dietary nitrites in well water, but may be unfamiliar with others, such as the ingestion Blue dye- ultramarine blue, chemical composition sodium aluminosulfosilcate, commonly used as fabric whitener in India.

Key words: Methemoglobinemia; Blue dye;Ultramarine blue; Methylene blue.