Contact dermatitis to neomycin sulfate.

The prevalence of contact allergic dermatitis and nonallergic irritant reactions to neomycin sulfate was determined in a large group of young adults who had a noteworthy exposure to topical antibiotics. Only two subjects (0.09%) had contact allergy proved by closed patch testing, while 20 (0.9%) had nonallergic irritant reactions to 20% neomycin sulfate and 17 (0.78%) had nonallergic reactions to one of the hydrophilic ointment bases. In a separate population of 653 children referred for diagnostic patch testing, only one subject had contact allergy to neomycin. All three subjects who had reactions had a history of repeated use of neomycin on chronically damaged skin. These results support the conclusion that intermittent use of neomycin on minor cuts and wounds is not associated with an excessive rate of sensitization.