D3.88 - Did the skin patch test sensitivity profiles change in young and middle-aged adult patients? Current data from a tertiary allergy clinic cohort

Allergic contact dermatitis (ACD) is an inflammatory skin disease characterized by a T-cell-mediated type IV hypersensitivity reaction resulting from exposure to environmental and occupational allergens. Allergen exposure patterns vary over time, depending on age, gender, and the use of cosmetics and personal care products. Data comparing age-specific sensitization profiles in young and middle-aged adults are limited. The aim of this study was to analyze the results of the European Standard Skin Patch Test in patients aged 18–64 years evaluated for suspected allergic contact dermatitis, according to age and gender; and to compare allergen sensitivity patterns and reaction severity among young adult (18–34), early middle age (35–49), and late middle age (50–64) groups.

Data from 2022 patients who underwent the European Standard Skin Patch Test at a tertiary care center between January 2019 and September 2025 were retrospectively analyzed. Tests were evaluated at 48 and 96 hours according to the International Contact Dermatitis Research Group (ICDRG) criteria. Positivity rates were statistically compared across age groups, genders, and years.

1039 (51.4%) of patients showed a positive patch test result for at least one allergen. The positivity rate was significantly higher in women (n=791, 76.1%) compared to men (n=248, 23.9%) (p=0.001). The most frequently detected allergen was nickel sulfate (n:528, 26.1%), followed by propolis (n=203, 10%), cobalt chloride (n=162, 8%), methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) (n:124, 6.1%), textile dye mixture (n=114, 5.6%), and fragrance mix I (n=96, 4.7%). The overall positivity rate was significantly higher in young adults (18–34 years) (n=561, 54%; p=0.012). In this age group, sensitivity to para-phenylenediamine (n=41, 65.1%; p=0.004) and formaldehyde (n=32, 68%; p=0.001) was statistically significant. When evaluated on an allergen basis, sensitivity to 2-hydroxyethyl methacrylate (HEMA) alone was significantly more frequent in women (n=19, 86.4%) than in men (n=3, 13.6%) (p=0.026). (Table 1) When changes in allergen sensitivity over the years have been examined, a significant increase in propolis sensitivity has been observed(Figure 1).

Our study reveals that contact allergen sensitivity in young and middle-aged adults changes with age, gender, and time. The higher overall sensitization frequency in women and the prominence of cosmetic-related allergens in young adults are noteworthy. The increase in propolis sensitivity and the observed decrease in metal allergens reflect changing environmental and lifestyle exposures. These findings can contribute to age-specific risk assessment in clinical practice, the identification of measures to reduce allergen exposure, and the updating of patch test panels.