Epidemiology of pediatric nickel sensitivity: Retrospective review of North American Contact Dermatitis Group (NACDG) data 1994-2014

Background: Nickel is a common allergen responsible for allergic contact dermatitis. Objective: To characterize nickel sensitivity in children and compare pediatric cohorts (≤5, 6-12, and 13-18 years). Methods: Retrospective, cross-sectional analysis of 1894 pediatric patients patch tested by the North American Contact Dermatitis Group from 1994 to 2014. We evaluated demographics, rates of reaction to nickel, strength of nickel reactions, and nickel allergy sources. Results: The frequency of nickel sensitivity was 23.7%. Children with nickel sensitivity were significantly less likely to be male (P <.0001; relative risk, 0.63; 95% confidence interval, 0.52-0.75) or have a history of allergic rhinitis (P =.0017; relative risk, 0.74; 95% confidence interval, 0.61-0.90) compared with those who were not nickel sensitive. In the nickel-sensitive cohort, the relative proportion of boys declined with age (44.8% for age ≤5, 36.6% for age 6-12, and 22.6% for age 13-18 years). The most common body site distribution for all age groups sensitive to nickel was scattered/generalized, indicating widespread dermatitis. Jewelry was the most common source associated with nickel sensitivity (36.4%). Limitations: As a cross-sectional study, no long-term follow-up was available. Conclusions: Nickel sensitivity in children was common; the frequency was significantly higher in girls than in boys. Overall, sensitivity decreased with age. The most common source of nickel was jewelry.