Sensitization pattern affects the asthma risk in Finnish adult population

There is a large global variation in the sensitization pattern and its association with allergic diseases. In temperate and tropical urban environments, mite monosensitization can be the predominant cause of allergic airway diseases, whereas in other environments, polysensitization is more typical. Sensitization to mite allergens associates with asthma. However, it is suggested that mite sensitization might play a minor role in Northern Europe. The aim of the study was to analyze how sensitization pattern affects the asthma risk in Finnish adults, with a special focus on mites.

A population-based case-control data (N = 523) from Finnish adult asthma patients with one or two matched controls were used. Asthma was diagnosed based on a typical history of asthmatic symptoms and lung function tests. The allergic sensitization was determined based on skin prick test (SPT) of five mites, three molds, and nine other aeroallergens. Information on demographics was obtained by a questionnaire.

The proportion of sensitization to any allergen was 55% in the asthma group and 39% in the control group (P = 0.001, OR 2.06, 95% CI = 1.35-3.14). Sensitization to animal dander, pollen, or Aspergillus fumigatus was associated with asthma. Polysensitization to more than one allergen types and the number of SPT-positive reactions associated with asthma, whereas sensitization to only one allergen type was not associated with asthma.

The large number of sensitizations to several types of allergens distinguishes subjects with asthma. Mite sensitization had little independent association with asthma in Finland.