Prevalence of asthma, rhinitis, and eczema from ISAAC survey of schoolchildren in Central Taiwan.

Asthma is a common disease among schoolchildren in Taiwan. It is clearly a trend that the prevalence of asthma, rhinitis, and eczema has been increasing in developed countries such as Taiwan, but the data remain limited. This study is part of an effort to evaluate the epidemiology of asthma, rhinitis and eczema in Taiwan and to assess the prevalence and severity of those disorders among school age in central Taiwan. The International Study of Asthma and Allergies in Childhood (ISAAC, phase III) standard written questionnaire was administered to 7,873 first grade schoolchildren, 6 to 8 years of age from 47 different elementary schools in Changhwa county, which is located in central Taiwan. The overall cumulative and 12-month prevalence of wheezing is 10.4% and 5.0%, respectively. The prevalence of diagnosed asthma by doctor is 7.0%. Rhinitis is 24.6% and eczema 18.0%. Multiple logic regression analysis shows that a higher prevalence of wheezing and rhinitis is associated with males. Among these school-age children, the peak incidence of asthma and rhinitis is in the winter months, especially in December and January.We also compared the prevalence of asthma, rhinitis, and eczema in two severely polluted areas in Changhwa County with the prevalence in less polluted parts of the county. One is the area near a huge petrochemical company, TaiHao Petroleum Company, located in the central area of the county. The other is XiZhao, a rural area located near an incinerator. These were compared with the less-polluted Coast-Area and with the rest Changhwa County area. The school-age children living near the TaiHao Company have a higher prevalence of wheezing, diagnosed asthma, and diagnosed eczema, but there are no differences for rhinitis. As for XiZhao and Coast areas, those children have significantly higher rates of nasal problems, diagnosed rhinitis, and eczema than the rest of the area, but we did not find a significant difference in the prevalence of asthma. Among school-age children who lived in the Coast area, we found a higher prevalence of rhinitis and nasal problems with associated itchy eyes than among children in other areas of the county.