The prevalence of allergic contact sensitization in a general population in Tromso, Norway

OBJECTIVES: This study investigated the prevalence of contact sensitization in a general adult population and the relationship between the history of metal dermatitis and sensitization to metal allergens. STUDY DESIGN: A cross-sectional population study using patch tests and a questionnaire was conducted among adults in Tromsø, Northern Norway. METHODS: A random sample of 830 participants aged 18-75 years were invited to participate in the patch testing and completed a 1-page self-administered questionnaire. Of the adults, 531 (64%) were actually TRUE tested (using a standardized, ready-to-apply patch test system) and completed the self-administered questionnaire about ear piercing, metal reactions, skin reactions to different allergens, atopic dermatitis, eczema, cooking equipment and diet. RESULTS: The study showed that nickel (19.2%; women 31.1% and men 5.0%), fragrance mix (3.4%) and cobalt (1.7%) were the most prevalent allergens causing contact sensitization. For all other allergens, less than 1.1% tested positive. Eighty-four (45.2%) subjects with a positive history of metal dermatitis had negative patch tests. CONCLUSIONS: Contact sensitization was found frequently in this general adult population, especially to nickel and perfumes with a predominance among females. An eczematous reaction caused by cheap earrings seemed to be the best indicator for metal sensitivity.