Airway hyperreactivity: managing outcomes and new directions

Bronchial hyperreactivity is defined as an increased sensitivity to bronchoconstrictor stimuli. It is regarded as the physiological hallmark of bronchial asthma. It is usually associated with a positive family history of asthma, atopy, and evaluated total serum immunoglobulin E. Its prevalence in the normal population ranges from 10 to 20%; it increases with age and is significantly associated with both allergic rhinitis and atopic dermatitis. The relationship between bronchial hyperreactivity and respiratory symptoms may be weak. Bronchial hyperreactivity varies in severity with allergen exposure, viral infection, exposure to pollutants, environmental avoidance measures, anti-inflammatory therapy, and immunotherapy.