Topically induced diphenhydramine toxicity.

We report the case of a 2 1/2-year-old child who manifested acute anticholinergic toxicity after the applications of a topical calamine-antihistamine lotion. This mechanism of diphenhydramine toxicity is uncommon, with only a few other case reports noted in the literature. This case is also intriguing in that this child had an underlying varicella illness with fever that tended to obscure the picture. This report describes the characteristic history and physical examination pertinent to anticholinergic toxicity, varicella complication considerations, and case management.