Patch test in children: Common allergens and comparison with adult group

Abstract

Background: Allergic contact dermatitis (ACD) was once regarded as a disorder of the adult population, while ACD in children was considered rare. However, ACD in children may be more common than previously realized and more recently, it has been estimated that more than 20% of the pediatric population is affected by ACD. However, in Korea results of patch testing in the pediatric population has not yet been reported. Objective: The purpose of this study was to analyze allergens responsible for ACD in Korean children and investigate the influence of sex, involved site, and atopic dermatitis on contact allergen sensitization. We also wanted to compare the results between the pediatric and the adult group. Methods: A retrospective analysis of all patch test results from our data base between 2009 and 2011 was performed. A total of 234 patients were patch tested. The pediatric population was defined as patients 18 years and younger, and total 30 pediatric patients were included. Results: A total of 30 patch tested cases (male 12, female 18) were analyzed. Overall, 66.7% of pediatric patients had at least one positive reaction and common allergens were nickel sulfate (33.3%), thimerosal (13.0%), and black rubber mix (10.0%) in order of frequency. There were no significant differences between contact allergen sensitivity and sex or involved sites. However, in the atopic group, the positive reactions to wool alcohols were significantly higher than in the non-atopic group (p=0.0076). In adults, common allergens were nickel sulfate (34.8%), p-tert butylphenol formaldehyde resin (11.8%), cobalt chloride (11.3%) and thimerosal (11.3%) in order of frequency. This was not significantly different to the pediatric group. Conclusion: ACD in children is not uncommon and patch testing in suspected children revealed 66.7% of positive reaction.