BACKGROUND: Although contact allergy among children was previously considered to be rare, data from the past decade have shown that it is common among children and that the prevalence may be increasing.

OBJECTIVES: To describe the demographics of all children referred for patch testing in Denmark during 2003-2011, to examine the frequency and relevance of positive patch test reactions, and to assess the most common allergens.

METHODS: A retrospective analysis of the patch test data from the Danish National Database of Contact Allergy was performed.

RESULTS: Of 2594 children and adolescents aged 1-17 years, 25.1% had one or more positive patch test reactions. The associated relevance was 66.4%. The most common sensitizers were metals, fragrances, and hair dyes. The frequency of positive patch test reactions and allergic contact dermatitis was significantly higher among girls.

CONCLUSIONS: Allergic contact dermatitis in children is a significant clinical problem. Contact allergy should always be considered when children with recalcitrant eczema are encountered, and special attention should be paid to girls. Patch testing is important, and children may be tested with the same patch test concentrations as adults.