Allergen skin test reactivity in an unselected Danish population. The Glostrup Allergy Study, Denmark.

The aim of this study was to assess the distribution of allergen skin test reactivity in an unselected Danish population. A total of 793 subjects, aged 15-69 years, were invited, and 599 (75.5%) attended. The skin prick test was performed with standardized allergen extracts of high potency. Skin reactivity occurred in 28.4% of the subjects. The frequency of skin reactivity to the specific allergens ranged from 1.5% (Cladosporium) to 12.5% (Dermatophagoides pteronyssinus), and the frequencies of skin reactivity to the allergen groups (pollen, animal dander, house-dust mites, and molds) were 17.6%, 8.7%, 14.0%, and 3.2%, respectively. Young women appeared to reflect the average skin reactivity. When compared with young women, skin reactivity to animal dander was more probable in young men (odds ratio (OR) value = 2.6; 95% confidence interval (CI) of odds ratio value = 1.1-6.1). Current smokers were less likely than nonsmokers to be skin-reactive to pollen (OR = 0.4; 95% CI = 0.3-0.7). In conclusion, allergen skin test reactivity was common, and was related to sex, age, smoking history, and probably genetic predisposition.