Allergic contact dermatitis in children: trends in allergens, 10 years on. A retrospective study of 500 children tested between 2005 and 2014 in one UK centre

BACKGROUND: Contact allergy in children is becoming increasingly recognized as a cause of eczema. The causal agents may change with time, but there are few comparative data for this age group. OBJECTIVES: To compare data from the past 10 years with a similar study from the previous decade. METHODS: Between 2005 and 2014, 500 consecutive children who had been patch tested at Leeds Teaching Hospitals were identified, and the results were reviewed. RESULTS: Twenty-seven per cent (134 cases) of children had one or more positive patch test findings. The mean ± standard deviation age of patients with a positive test reaction was 11.9 ± 4.1 years, which was significantly higher than that of patients with a negative result (10.9 ± 4.0 years) (p = 0.01; Mann-Whitney U-test). No significant relationship between sex and a positive patch test result was found (p = 0.48, chi-squared). Allergy to nickel was the most frequent finding, although this accounted for 18%, rather than 33% (1995-2004), of all positive reactions. The next most common allergens included fragrance mix 1 (17%), p-phenylenediamine (16%), and methylchloroisothiazolinone/methylisothiazolinone (6%). CONCLUSIONS: Although the overall incidence of contact allergy in our paediatric population is static, there has been a significant change in the allergens detected, probably as a result of changes in European legislation and cosmetic product use in children.