Allergen avoidance as primary prevention: con.

There has been a dramatic increase in the prevalence of atopic diseases, such as atopic dermatitis, food allergy, allergic rhinitis, and allergic asthma. Because environmental factors such as early allergen exposure to nutritional and inhalant allergens have been suspected as potential environmental factors favoring the development of allergic diseases and asthma, primary prevention studies have begun to investigate the effect on sensitization and wheezing. Designs of the studies are different and, therefore, are not completely comparable. Although no clear primary prevention study is available for pets, mite allergen avoidance during infancy can achieve a reduction of specific sensitization and, in some studies, can also produce a slight effect on respiratory symptoms.