Epidemiology of contact allergy in adults

TLDR

Contact sensitization prevalence in the general adult population is poorly characterized. This study aimed to determine its prevalence and examine associations with sociodemographic and medical factors. The study used a population‑based nested case‑control design, patch‑testing 1,141 adults with 25 standard allergens, and collected dermatologic, interview, and blood data. Overall, 40% of participants had at least one positive patch test, with fragrance mix (15.9%) and nickel (13.1%) most common, and prevalence estimates for the adult population were 28% overall, 11.4% for fragrance mix, 9.9% for nickel, and 3.2% for thimerosal, with higher rates in women and those reporting skin reactions.

Abstract

Background: We aimed to determine the prevalence of contact sensitization in the general population and to investigate associations with important sociodemographic and medical characteristics. Methods: Within a population‐based nested, case‐control study in Germany, we performed patch tests with 25 standard allergens in 1141 adults (50.4% female, age median 50 years). Additional information was obtained by a dermatologic examination, a standardized interview, and blood analysis. Results: At least one positive reaction was exhibited by 40.0% of the subjects, with reactions most frequently observed to fragrance mix (15.9%), nickel (13.1%), thimerosal (4.7%), and balsam of Peru (3.8%). Women were sensitized more often than men (50.2% vs 29.9%, OR 2.36, CI 1.84–3.03), and this was also significant for fragrance mix, nickel, turpentine, cobalt chloride, and thimerosal. Contact sensitization was more frequent in subjects who reported adverse skin reactions (53.8% vs. 32.6%; OR 2.41, CI 1.85–3.14), and this was particularly true for sensitization to nickel (45.5% vs 8.8%, OR 8.64, CI 5.67–13.17) and fragrance mix (29.0% vs 14.0%, OR 2.51, CI 1.60–3.91) and the corresponding intolerance of fashion jewelry and fragrances. Contact sensitization decreased with increasing degree of occupational training (unskilled 45.9%, apprenticeship 40.1%, technical college 40.4%, and school of engineering 12.5%; P =0.023; trend test P =0.042). Significant associations of contact sensitization and presence of allergen‐specific IgE antibodies, atopic eczema, or psoriasis were not observed. Frequency estimates for the general adult population based on these findings were 28.0% for overall contact sensitization and 11.4% for fragrance mix, 9.9% for nickel, and 3.2% for thimerosal. Conclusions: It is concluded that contact allergy is influenced by sociodemographic parameters and plays an important role in the general population.