Prevalence of allergic contact dermatitis in children with and without atopic dermatitis: A multicenter retrospective case-control study.

BACKGROUND: As both allergic contact dermatitis and atopic dermatitis (AD) have similar clinical presentations and are characterized by spongiotic dermatitis on skin biopsy, many children with AD are not referred for patch testing and allergic contact dermatitis is underdiagnosed. OBJECTIVE: To provide updated prevalence data of common contact allergens in children with and without AD. METHODS: This is a retrospective case-control study using the Pediatric Allergic Contact Dermatitis Registry from 2018 to 2022. RESULTS: A total of 912 children were included (615 with AD and 297 without AD). Children with AD were more likely to have a longer history of dermatitis (4.1 vs 1.6 years, P < .0001), have seen more providers (2.3 vs 2.1, P = .003), have greater than 1 positive patch test (PPT) result (P = .005), have a greater number of PPT results overall (2.3 vs 1.9, P = .012), and have a more generalized distribution of dermatitis (P = .001). PPT to bacitracin (P = .030), carba mix (P = .025), and cocamidopropyl betaine (P = .0007) were significantly increased in children with AD compared to those without AD. LIMITATIONS: Technical variation between providers and potential for misclassification, selection, and recall biases. CONCLUSION: Children with AD are significantly more likely to have PPT reactions and should be referred for evaluation of allergic contact dermatitis and obtain patch testing.