TOPLINE:
Contact allergy affects children across different geographical regions, with nickel being the most prevalent allergen (11.9%), followed by cobalt (6.6%), according to a meta-analysis. The analysis also finds that children with atopic dermatitis show increased rates of positive patch tests for cocamidopropyl betaine, propylene glycol, lanolin alcohol, and carba mix.
METHODOLOGY:
- Researchers conducted a meta-analysis of 17 studies involving 11,593 children (mean age, 11.3 years), 4176 (36%) of whom had positive patch tests, to evaluate the allergens responsible for contact allergy between 2010 and 2024.
- Of the studies included, three were conducted in the United States, two each were conducted in Italy, Sweden, Israel, and Denmark, and one each was conducted in the Czech Republic, Turkey, Thailand, India, the Netherlands, and Belgium.
- The analysis also included data from children with atopic dermatitis, accounting for 36.8% of the study population and 1955 positive patch tests.
TAKEAWAY:
- Nickel sulphate emerged as the most prevalent allergen, with a positive patch test rate of 11.9% (95% CI, 8.6%-15.7%), followed by cobalt chloride at 6.6% (95% CI, 4.2%-9.5%).
- Fragrance mix I showed a positive patch test rate of 4.8% (95% CI, 2.9%-7.1%), whereas preservatives such as methylisothiazolinone showed a rate of 4.3% (95% CI, 2.2%-7.2%).
- Children diagnosed with atopic dermatitis showed elevated rates of positive patch tests for specific allergens, including cocamidopropyl betaine, propylene glycol, lanolin alcohol, and carba mix.
- Geographical analysis revealed that several allergens, particularly methylisothiazolinonein, were more prevalent in the United States than in Europe.
IN PRACTICE:
"CA [contact allergy] is frequent in children across different geographical regions, though there are significant differences in the pooled prevalence of high-prevalence allergens such as nickel, MCI/MI [methylchloroisothiazolinone/methylisothiazolinone], MI, and fragrances. These variations solely depend on regulatory interventions to highlight their importance. The observed waxing and waning of allergen prevalence underscores the importance of consistent regulatory oversight to minimise the risk of emerging sensitivities and protect public health," the authors wrote.
SOURCE:
The study was led by Daniel Isufi, Department of Dermatology and Allergy, Herlev and Gentofte—Copenhagen University Hospital, Copenhagen, Denmark. It was published online on January 19, 2025, in Contact Dermatitis.
LIMITATIONS:
Researchers noted significant between-study heterogeneity for most allergens, which was likely influenced by geographical and study-related factors, potentially affecting the prevalence estimates. While most studies utilised consistent allergen concentrations and vehicles, facilitating comparability, some allergens were reported in limited studies despite large sample sizes. Additionally, the selection of allergens for paediatric testing was often according to prevalent allergens observed in adult populations from the same geographical regions, potentially missing unique paediatric exposures.
DISCLOSURES:
The authors reported that no specific funding was received for this research. The authors did not declare any conflicts of interest.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.
