Allergic contact sensitization in the general adult population: a population-based study from Northern Norway.

Few studies have so far addressed the prevalence and risk factors for contact sensitization in the general adult population; however, many such studies have been conducted in hospitals. We present the prevalence of contact sensitization in a general adult population and its relationship to potential risk factors like smoking, ear piercing and atopic diseases. 1236 adults (44.2% men and 55.8% women) were randomly selected from a cross-section of the population in Sør-Varanger municipality, Norway, and patch tested with TRUE Test (Pharmacia, Hillerød, Denmark). Contact sensitivity to at least 1 out of 24 allergens was found in 35.4% of the women and in 14.8% of the men. The most common allergens were nickel (17.6%), cobalt (2.8%), thiomersal (1.9%), fragrance mix (1.8%) and colophony (1.2%). All other allergens were observed in 1.0% or less. In women, ear piercing was an important risk factor for nickel sensitization. No such significant correlation was seen in men [in women relative risk (RR) = 3.30, 95% confidence interval (CI) = 2.01-5.43, and in men RR = 1.82, 95% CI = 0.66-5.00], and contact sensitivity was associated with atopic dermatitis (AD) [adjusted odds ratio (OR) = 1.58, 95% CI = 1.04-2.40] and smoking (adjusted OR = 1.42, 95% CI = 1.01-1.99) in women but not in men. The prevalence of contact sensitivity was common in this general population, especially in women. Smoking and AD might be a risk factor for contact sensitization.