Effect of reflux on cough sensitivity and bronchial responsiveness

Gastroesophageal reflux is an extremely common condition often associated with chronic cough, dyspnea, laryngeal discomfort, and other extraesophageal symptoms. A considerable body of evidence has established an association of reflux with the presence of cough reflex hypersensitivity and/or bronchial hyperresponsiveness. However, the demonstration of such airway hyperreactivity does not uniformly predict the presence of underlying pathology nor the occurrence of symptoms. Furthermore, treatment aimed at suppressing cough reflex sensitivity or bronchial responsiveness, even when successful, often fails to ameliorate associated symptoms. Given that reflux, cough, and asthma are all very common conditions, the association of reflux with cough reflex hypersensitivity and bronchial hyperresponsiveness is likely causal in some individuals and coincidental in others. Adequately performed clinical trials evaluating the presence of pathological reflux, its effect on cough reflex sensitivity, airway responsiveness and pulmonary symptoms, as well as objective and symptomatic response to therapeutic interventions, will be most useful in elucidating the pathophysiologic manifestations of reflux on the respiratory system.