[Asthma and nonspecific bronchial hyperreactivity]

Bronchial hyperresponsiveness is a hallmark of asthma although it can also be present, to a lesser extent, in other diseases. The level of bronchial responsiveness depends on immuno-inflammatory processes modifying the functional status of airway smooth muscle as well as the structure of the bronchial wall. The responsiveness toward a direct constricting pharmacological agent is poorly correlated to the one toward an indirect constricting agent or a physical stimulus which cause airway obstruction through a more complex mechanism. Transversal studies show a relationship between the severity of asthma and the level of methacholine airway responsiveness. Long term treatment with corticoids can reduce the bronchial hyperresponsiveness of asthmatics.