Dr. Wolfe: I shall discuss two cases of methemoglobinemia which we have seen in the past 2 years produced by the application of benzocaine ointment. These are, as far as I have determined, the first reported cases of methemoglobinemia due to benzocaine (ethyl aminobenzoate), and indeed the first cases of methemoglobinemia due to the application of an ointment.
The first of these patients was admitted in 1954 at the age of 7 weeks. Birth and neonatal history were normal. Eczema began at the age of 4½ weeks. The baby was treated with a variety of ointments and dietary changes without improvement.
The infant was admitted to the Babies Hospital at 7½ weeks of age on the day the parents had been given an ointment, which they were told contained coal tar. At 7 o'clock that evening the ointment was applied widely to the baby's skin. Approximately 45 minutes later the mother heard the baby screaming. On entering the infant's room she found that the color of his skin was black. She rushed the baby to the hospital where the diagnosis of methemoglobinemia was suggested. Blood was obtained and was found to appear chocolate brown. The baby was given 3 ml of a 1% solution of methylene blue, intravenously. This brought about a prompt change in the color; within 10 minutes the baby was no longer cyanotic.
Marked tremors had been noted on admission. These continued throughout most of the evening but by the next morning had entirely disappeared. The baby was discharged home the following morning without further laboratory investigation. Neither the concentration of methemoglobin in the blood nor any other laboratory data were obtained.
- Copyright © 1957 by the American Academy of Pediatrics