Prevalence and risk factors of allergic sensitization in Swiss school children

The aim of the present analysis of the SCARPOL Study (Swiss Study on Childh ood Allergy and Respiratory Symptoms with respect to Air Pollution and Clim ate) was to assess the prevalence of allergic sensitization in 3 age groups of children and to establish risk factors of allergic sensitization. More specifically, it was of interest whether children living in more polluted c ommunities were at higher risk of being sensitized than children in less po lluted areas. Methods: 2,879 (6.4%) of 4,470 children with a completed pare ntal questionnaire underwent skin prick testing (SPT) against 6 common aero allergens (grass mixture, birch, mugwort, D. pteronyssinus, cat and dog dan der). Three age groups of children participated in the study: 6- - 7-year-o lds (Ist grade), 9- - 11-year-olds (4th grade), and 13- - 15-year-olds (8th grade). Results: 35.7% of the children were sensitized against at least on e tested allergen, 22.5% were sensitized against grass pollen, 12.4% agains t house dust mites, and 11.4% against birch pollen. A family history of ato py and older age of the children were associated with an increased risk of sensitization, whereas an increasing number of siblings lowered the risk. T here was no relationship between levels of community air pollution and the prevalence of allergic sensitization. Conclusions: The prevalence rates of allergic sensitization in Swiss schoolchildren are comparable to those obse rved in Germany. Indicators of indoor air pollution such as smokers in the home, visible molds, pets, and outdoor air pollution were not associated wi th allergic sensitization.