Bronchial hyperresponsiveness

Bronchial hyperresponsiveness (or other combinations with airway or hyperreactivity) is a state characterised by easily triggered bronchospasm (contraction of the bronchioles or small airways).

Bronchial hyperresponsiveness can be assessed with a bronchial challenge test. This most often uses products like methacholine or histamine. These chemicals trigger bronchospasm in normal individuals as well, but people with bronchial hyperresponsiveness have a lower threshold.

Bronchial hyperresponsiveness is a hallmark of asthma but also occurs frequently in people suffering from chronic obstructive pulmonary disease (COPD).^[1] In the Lung Health Study, bronchial hyperresponsiveness was present in approximately two-thirds of patients with non-severe COPD, and this predicted lung function decline independently of other factors.^[2] In asthma it tends to be reversible with bronchodilator therapy, while this is not the case in COPD.

Footnotes

1. ^ Postma DS, Kerstjens HA (November 1998). "Characteristics of airway hyperresponsiveness in asthma and chronic obstructive pulmonary disease". Am. J. Respir. Crit. Care Med. 158 (5 Pt 3): S187–92.  
2. ^ Tashkin DP, Altose MD, Connett JE, Kanner RE, Lee WW, Wise RA (June 1996). "Methacholine reactivity predicts changes in lung function over time in smokers with early chronic obstructive pulmonary disease. The Lung Health Study Research Group". Am. J. Respir. Crit. Care Med. 153 (6 Pt 1): 1802–11.