EFFECTS OF INHALED CORTICOSTEROIDS ON THE CONSEQUENCES OF ASTHMA

Asthma is a chronic inflammatory disease of the airways involving a ch aracteristic pattern of airway infiltration with lymphocytes, eosinoph ils, and mast cells, subepithelial deposition of collagen, and hypertr ophy and hyperplasia of smooth muscle and of goblet cells and submucos al glands. The consequences of this chronic process include episodic o r persistent symptoms, bronchial hyperreactivity, attacks of bronchoco nstriction that may require emergency care or hospitalization and can lead to death, impairment in quality of life, and the development of i rreversible airflow obstruction, Careful pathologic studies have shown that inhaled corticosteroid therapy can reverse or suppress airway in flammation, and prospective controlled clinical trials have proven tha t it can also improve symptoms, reduce bronchial hyperreactivity, and reduce the frequency and severity of attacks. It is also highly likely , although it is not yet proven, that inhaled corticosteroid therapy r educes the risk of asthma fatality and prevents or retards airway wall remodeling. These beneficial effects are easily shown in patients wit h moderate or severe asthma, Although inhaled corticosteroid therapy a lso benefits patients with mild asthma, it is less certain that the co sts and risks of continuous therapy are justified. For these patients, the most important issues that remain to be resolved are the nature o f the risk of development of permanent airflow obstruction and the eff ects of early, sustained treatment on the chances of sustained remissi on of asthma after all therapy has been stopped.