Epidemiology Of Pediatric Asthma

Childhood asthma is one of the most common chronic respiratory disorders affecting up to 30% of school children in the developed world. Many epidemiology studies have consistently documented an increasing trend of asthma over the past three decades [1]. A few recent reports suggested that there is a plateau or even decline in the trend of asthma prevalence [2–4]. Due to the lack of precise definitions of asthma and validation of survey instruments, reliable comparison of reported prevalence studies from different regions are very difficult. A number of large multicentered epidemiological studies using standardized instruments have been performed revealing important information on the prevalence and burden of asthma around the world [5–7]. They have also provided a framework to investigate the possible determinants of asthma. Studies in the rural areas have consistently showed a lower prevalence of asthma in children who have been brought up in a farming environment [8–11]. This chapter reviews the existing data on asthma epidemiology and summarizes the recent important findings from studies of the environmental determinants of childhood asthma.