Allergens Responsible for Contact Allergy in Children From 2010 to 2024: A Systematic Review and Meta-Analysis

Contact allergy (CA) is a frequent condition in children; however, newer estimates of the prevalence of CA in children are lacking. Herein, we aim to provide an estimate of the prevalence of CA in children from 2010 to 2024. Two authors independently searched PubMed, Embase and Web of Science for studies reporting the prevalence of positive patch tests (PPTs) to allergens in populations including ≥ 100 children (< 18 years). Proportion meta-analyses were conducted to calculate the pooled prevalence estimates of CA in children. Seventeen studies comprising 11 593 children undergoing patch testing with 4176 (36%) PPTs were eligible for inclusion. The allergen with the highest prevalence was nickel (11.9% [95% confidence interval [CI], 8.6%-15.71%]), followed by cobalt (6.6% [95% CI, 4.2%-9.5%]), cocamidopropyl betaine (5.5% [95% CI, 3.1-8.7]), bacitracin (5.2% [95% CI, 1.2%-10.0%]), fragrance mix I (4.8% [95% CI, 2.9%-7.1%]) and methylisothiazolinone (4.3% [95% CI, 2.2%-7.2%]). Children with atopic dermatitis had higher rates of PPTs for cocamidopropyl betaine, propylene glycol, lanolin alcohol and carba mix. Across geographical areas, higher prevalences of several allergens were found in the United States compared to Europe, for example, for methylisothiazolinone. This meta-analysis confirmed that CA is frequent in children across geographical areas; however, differences in the frequency of top allergens depend on regulatory interventions, indicating their value.