[Association of benzocaine and paracetamol with neonatal-acquired methemoglobinemia].

Background: Drug-induced acquired methemoglobinemia in the newborn is a rare event; however, when it develops, early diagnosis and proper treatment become paramount because it can evolve rapidly into a particularly serious disease causing permanent brain damage or death.

Case Report: We report a unique case of severe methemoglobinemia that developed in a newborn associated with a minimal application of a benzocaine healing cream to an anal surgical wound while on acetaminophen. In addition to benzocaine as the primary cause in this case, we raise the possibility that acetaminophen-a mild oxidant-increased the susceptibility of the patient to benzocaine, leading to severe clinical methemoglobinemia based on the known immaturity of the enzymatic systems involved in caines and acetaminophen clearance in the newborn.