Contact Sensitization in Adults With Atopic Dermatitis: A 21‐Year Single‐Center Tertiary Experience

Background: Atopic dermatitis is a common chronic inflammatory skin condition. Data on contact sensitization in adults with atopic dermatitis remain limited. Objectives: To investigate the prevalence of contact sensitization in adults with and without AD:. Patients/Methods: A monocentric, retrospective study analysed 8967 adults (≥ 16 years) patch-tested at the University of Padua (1997–2018). Patients were tested with a standard baseline series (44 allergens). 540 (6.0%) patients had atopic dermatitis; 8273 (92.3%) did not; 154 (1.7%) had missing/uncertain AD status and were excluded from subgroup comparisons. Results: Contact sensitization prevalence was 65.4% in both groups. Adults with atopic dermatitis showed significantly higher rates of sensitization to formaldehyde (p < 0.00001), HICC (hydroxyisohexyl 3-cyclohexene carboxaldehyde) (p = 0.04), thiuram mix (p = 0.03), and carba mix (p = 0.004). Non-AD patients showed significantly higher sensitization to nickel (p = 0.001), disperse blue (p = 0.006), and primin (p = 0.05). Nickel was the most frequent allergen (21.30% AD; 27.59% non-AD). Conclusions: Higher prevalence of contact sensitization to specific allergens in adults with atopic dermatitis suggests a tailored patch test series including allergens from rubber, fragrance, and preservative groups. The lower prevalence of metal sensitization in patients with atopic dermatitis may reflect distinct immunological mechanisms that warrant further research.