ABSTRACT

Asthma is a disease characterized by the presence of symptoms such as dyspnea, wheezing, chest tightness, and cough. These symptoms are usually caused by airflow obstruction, which is characteristically variable. Asthmatics are also known to have airway hyperresponsiveness to a variety of chemical bronchoconstrictor stimuli and physical stimuli such as exercise and hyperventilation of cold dry air (1). More recently, it has been recognized that asthma symptoms, variable airflow obstruction, and airway hyperresponsiveness occur as a consequence of a characteristic form of cellular inflammation and structural changes in the airway wall (2). The inflammation consists of the presence of activated eosinophils, lymphocytes, and an increased number of mast cells. Also, the structural changes described in asthmatic airways appear to be characteristic of the disease and are likely caused by persisting airway inflammation.