Allergic contact dermatitis to chlorhexidine in children.

Background: Hypersensitivity to chlorhexidine is rare in children. The usefulness of different diagnostic tests for allergic contact dermatitis (ACD) is unknown.
Objective: We aim to describe a case series of children with hypersensitivity to chlorhexidine and to compare the results of different diagnostic tests.
Patients: Nine children with hypersensitivity to chlorhexidine were included. Only six of these children and their parents consented to a comprehensive allergy assessment, which included the prick test, intradermal test, patch test, and repeated open application test (ROAT).
Results: Seven children (78%) presented symptoms of chlorhexidine hypersensitivity within the first 5 years of life; two of them before the age of 1 year. In four children, the dermatitis lesions were suggestive of wound superinfection. All six children who participated in the comprehensive diagnostic evaluation had negative results on the prick test. The immediate-reading intradermal test was positive in one case and uncertain in two cases. The patch test was positive in five cases, and the ROAT was positive in all six cases when using 2% chlorhexidine alcohol solution.
Conclusion: ACD to chlorhexidine in children appears to be rare and can be difficult to detect. Clinicians should consider this diagnosis when wounds worsen with chlorhexidine. Although the patch test is the most standardized method for detecting ACD, the ROAT with 2% chlorhexidine alcohol solution was the most sensitive test in our patients.