Multi-center retrospective evaluation of oral benzocaine exposure in children

On rare occasions benzocaine has produced methemoglobinemia from oral, rect al and dermal exposures. There is disagreement whether this is an idiosyncr atic event or a dose-related event. To gain a better perspective on this pr oblem we retrospectively reviewed cases at 4 large regional poison centers of children <18-y of age from 1993-1996. One hundred and eighty-eight benzo caine exposures were reported. Mean and median ingested dosage were 86.8 (/- 89.5) mg/kg and 50 mg/kg, respectively. Fifty-eight patients (30%) were managed in the emergency department: 8 patients had methemoglobin levels de termined. One child had a methemoglobin level of 19%; all others were <1%. One hundred and seventy-three patients (92%) remained asymptomatic. Other s ymptoms were minor: oral numbness (8), vomiting (3), and I each of oral irr itation, dizziness and nausea. In this series of accidental ingestions of b enzocaine containing products cyanosis was Fare and apparently not dose rel ated. These cases may be safely managed at home with telephone follow up fo r at least 2 h. If there is evidence of cyanosis, dusky pallor, shortness o f breath, or change in mental status direct medical evaluation should be re commended.