Allergic contact dermatitis in children with and without atopic dermatitis

Background Prevalence and causes of allergic contact dermatitis (ACD) in children vary with time and geographical area. Objective This study aimed to determine the relevant allergens causing ACD in children and the relation between ACD and atopic dermatitis (AD). Methods A cohort study on 349 children (0-15 years old) patch tested over a 7-year period was conducted. Results Patch test results were positive for at least 1 allergen in 69.3% of patients and were relevant in 69.8%. The highest sensitization rate (76.7%) was observed in children who are 0 to 5 years old (n = 86, 64% females), followed by the group of 6- to 10-year olds (70%, n = 157, 47.8% females), whereas 62.3% of 11- to 15-year-old children (n = 106, 59.4%) were sensitized. The most frequent allergens were nickel (16.3%), cobalt (6.9%), Kathon CG (5.4%), potassium dichromate (5.1%), fragrance mix (4.3%), and neomycin (4.3%). Body areas mostly affected were upper limbs and hands (31%). Approximately one third of children also had AD. Allergic contact dermatitis was more widespread in children with AD. Patch tests resulted positive in 55.3% (50% relevant) of AD compared with 76.9% (77.5% relevant) of the children without AD. Sensitizers were similar to children without AD. Conclusions Very young children showed a high rate of relevant positive patch test reactions to common haptens. Allergic contact dermatitis may easily coexist with AD.