Asthma

Asthma is characterised by intermittent airway obstruction, bronchial smooth muscle cell hyper-reactivity to broncho-constrictors, and chronic bronchial inflammation. The aetiology of asthma is heterogeneous with a number of established risk factors. The prevalence of asthma has been increasing in all age and racial groups during the past two decades. The variation in prevalence rates for racial and ethnic groups probably results from differences in genetic, environmental, social, and cultural influences. Factors affecting increased asthma prevalence include obesity and exposure to environmental irritants. The population has become increasingly sedentary, spending more time indoors where the exposure to allergens, such as mould, dust mites, and cockroach dust, is more prevalent. In addition, the increased prevalence of allergic rhinitis and atopy related to exposure to allergens at an early age is associated with the prevalence of asthma. This book provides new research on this field from around the globe.