Benzocaine-induced methemoglobinemia.

Intense cyanosis in a previously well, 30-month-old, white girl was found to be due to the ingestion of benzocaine. A wide variety of chemical compounds present in many proprietary products, when ingested, can cause this presentation in individuals with structurally normal hemoglobin and normal activity of methemoglobin reductase. The phenomenon appears to be dose-related. Immediate recognition and initiation of appropriate therapy will effect a rapid reversal of the methemoglobinemia, and in some cases, may be life-saving. Caution should be exercised in the use of benzocaine-containing preparations.