ASTHMA - THE IRREVERSIBLE AIRWAYS DISEASE

Chronic inflammation of the asthmatic airway leads to epithelial desqu amation, goblet cell hyperplasia, mucosal and submucosal inflammation, prominent smooth muscle, and collagen deposition below the basement m embrane. The changes in the airway are attributed to chronic inflammat ion, the healing process and subsequent remodeling. These changes cont ribute to three predominant mechanisms of increased airway resistance in asthma: decreased elastance of airways; increased smooth muscle in the airway which may cause increased narrowing during bronchospasm; an d collagen deposition beneath the basement membrane resulting in airwa y wall thickening. Destruction and subsequent remodeling of the normal bronchial architecture are manifested by a progressive decline in FEV 1. In an attempt to decrease the progressive decline in FEV1, studies on proper therapy have been undertaken. Antiinflammatory medications, such as inhaled corticosteroids, have been shown to decrease this rate of decline in lung function, while the effect of bronchodilators is l ess conclusive. Beginning treatment with inhaled corticosteroids early produces a better clinical response compared to initiating treatment late, and early treatment may prevent airway remodeling and developmen t of irreversible structural changes.