An infant with sepsis and methemoglobinemia.

A 3-week-old child arrived at the emergency room with the concurrent onset of sepsis and methemoglobinemia associated with diarrhea. Subsequently, the child had two recurrent episodes of methemoglobinemia with re-exacerbations of his diarrhea. Possible causes and associations of methemoglobinemia are presented: particular emphasis is placed on the early recognition and rapid diagnosis of this life-threatening condition.