Pathogenesis of asthma.

Asthma is the most common chronic lower respiratory tract condition in children. Thus, it is imperative that physicians caring for asthmatic patients understand the pathophysiology of asthma and its implications for optimal therapeutic management. A precise understanding of asthma pathophysiology has been impeded due to the fact that a universally acceptable definition for asthma has been difficult to formulate. Clinicians treating asthmatic patients should be aware that the airway obstruction present in these individuals is the result of multiple interrelated factors. Although bronchial smooth muscle spasm can be effectively treated producing rapid symptomatic relief, other factors contributing to airway obstruction, such as airway inflammation and edema, need to be a major focus of therapeutic strategies for more chronic management. While the concepts of reversibility and hyperresponsiveness have been appreciated for some time, the idea that asthma should be viewed as an inflammatory lung disease (or syndrome) has only recently received appropriate emphasis. In this regard, the late phase asthmatic response has provided a convenient model to study the biochemical and cellular interactions that contribute to the pathogenesis of asthma. Further, these responses will aid in the analysis of the potential beneficial effects of various pharmaceuticals as they undergo development and testing for use in asthmatic patients.