[Risk of exposure of children to indoor air allergens]

The development of allergic sensitization and disease in children depends mainly upon the genetic predisposition, the time and extent of exposure against allergens and upon environmental factors. Allergen avoidance in infancy substantially lowers the frequency of sensitization and allergic manifestations. In Germany mite allergens are the most important indoor allergens followed by cat allergens and fungal allergens. Private houses bear the greatest risk of exposure to mite allergens. Nevertheless in day nurseries there is a considerable amount of dust samples with mite allergen levels greater than 10 micrograms/g dust (18% of mattresses, 15% of soft toys, pillows etc.). Cat allergen levels in day nurseries and schools are similar to those in houses where a cat has never been kept. There is a correlation between the percentage of children who have cats at home and the cat allergen levels in dust. In an own study the mean numbers of fungal particles in dust samples from day nurseries were higher compared with those from private houses. Higher numbers of fungal particles concerned mostly day nurseries with flat roof and moisture problems. We conclude that generally private houses offer the highest risk of exposure to indoor allergens. In addition public places like day nurseries or schools must be taken into consideration as significant allergen sources.