Contact allergy in children with and without atopic dermatitis: An Italian multicentre study.

Background: Contact allergy and atopic dermatitis (AD) are both common inflammatory T cell-mediated diseases and many factors may influence the prevalence of contact allergy in AD patients. In children, their possible correlation was debated with conflicting results.

Objectives: The present study aimed to assess the prevalence of contact sensitivity in children and to investigate the association with AD.

Materials And Methods: A retrospective multicentre study on children aged from 0 to 14 years patch tested between January 2017 and December 2018 was performed. Children were consecutively patch tested with the SIDAPA (Società Italiana Dermatologia Allergologica Professionale Ambientale) baseline series.

Results: Among the 432 children investigated for contact allergy, 125 (28.9%) showed a positive reaction to at least one of the allergens tested, with a higher prevalence of positive patch test reactions in girls (32.3%) than in boys (25.0%). The most frequent contact allergens were nickel sulphate (10.2%), cobalt chloride (6.7%), methylisothiazolinone (3.7%), fragrance mix-2 (3.2%), potassium dichromate (2.8%), fragrance mix-1 (2.1%) and methylchloroisothiazolinone/methylisothiazolinone (2.1%). One-hundred-three children (23.8%) suffered from AD showing a higher prevalence of positive patch test (36.9%) compared to children without AD (26.4%).

Conclusions: Despite the topic being still controversial, the present study suggests a consistent prevalence of contact allergy among children with higher sensitivity rate among children with AD than without AD.