Aerosol and oral corticosteroids in the treatment of asthma.

The cause of asthma is unknown. However, it is now thought that the major abnormality is an underlying inflammation of the airway wall which persists, to some extent, between attacks. This inflammation manifests itself as bronchial hyperresponsiveness (BHR) which can be measured by inhalation tests from which dose response curves are derived. Using aerosol and oral forms of corticosteroid drugs in a group of asthmatics it was found that the aerosol form of the drugs reduced the severity of BHR, while the oral drugs had little or no effect. These findings suggest that superficial structures in the airways, perhaps the epithelial cells, are important in mediating BHR in patients with asthma.