Exploring the relationship between allergic contact dermatitis and atopic dermatitis in children: insights from a retrospective patch testing analysis

Background: Recent years have seen significant exploration into the potential link between allergic contact dermatitis and atopic dermatitis, yielding contradictory findings. Methods: A retrospective cohort analysis of children aged 2 to 18 who underwent patch testing at the pediatric dermatology clinic at a tertiary medical center in Israel was conducted. Results: Overall, 367 patients were included in the study, 31.6% of whom were diagnosed with atopic dermatitis. 160 children (43.6%) exhibited a positive reaction to at least one compound in the European baseline series. There was no statistically significant difference in reactivity between children with atopic dermatitis and those without (P = 0.848). Sub-analyses based on ethnicity, gender, and age did not reveal significant differences in overall European baseline series reactivity (P = 0.612, P = 0.446, P = 0.488, respectively). Sensitivity was notably higher when patch readings were conducted 72 h after application compared to 48 h [0.95 (CI: 0.91–0.97) vs. 0.60 (CI: 0.55–0.66)]. Conclusions: Patch testing is imperative for suspected cases of allergic contact dermatitis in all children, regardless of their atopic background. Further research is warranted to potentially replace the traditional 48-h reading with a single 72-h reading in future guidelines, contributing to enhanced efficiency and cost-effectiveness in clinical practice.