The prevalence of allergic diseases -The prevalence of atopic disease is decreasing・ from the surveillance in Himeji-

Abstract

We surveyed about 5,000 primary school children aged six every year in Himeji-City, Japan, from 1995 to 2010, using the Japanese version of the American Thoracic Society and the Division of Lung Diseases (ATS-DLD) questionnaire. The questionnaire survey showed that the prevalence of atopic dermatitis decreased significantly from 17.5% in 1995 to 9.4% in 2010 (P<0.001). The prevalence of asthma decreased slightly from 17.5% in 1995 to 4.8% in 2010 (P=0.016). However the prevalence of allergic rhinitis, allergic conjunctivitis and Japanese cedar pollinosis increased significantly from 8.6%, 3.6%, 6.7% in 1995 to 11.1%, 4.5%, 8.2% respectively (P<0.001, P<0.001, P<0.001). Decreasing prevalence of atopic dermatitis was associated with decreasing rugs and carpets sales, and with decreasing tatami mats sales in Japan, suggesting that atopic dermatitis was linked to the dust mites. The increasing prevalence of allergic rhinitis, allergic conjunctivitis and Japanese cedar pollinosis was presumably due to a large amount of cedar pollens.