Acid Reflux and Chronic Cough
Acid gastroesophageal reflux commonlycauses chronic cough, and response to acidsuppression therapy generally is lower thanit is in patients with heartburn. Improvementafter antireflux surgery suggests involvementof a nonacidic gastric component in therefluxate. As reported in the April 2005 issueof Gut, in a study involving 28 patients whowere evaluated using 24-hour ambulatorypressure-pH-impedance monitoring, DanielSifrim, MD, PhD, and colleagues investigatedwhether chronic cough is associated withweakly acidic reflux. Manometry for preciserecognition of cough and impedance-pHmetrywere used to detect acidic (pH <4),weakly acidic (pH 4-7), and weakly alkaline(pH ≥7) reflux.
Most coughs (69.4%) were consideredindependent of reflux, and 31% occurredwithin 2 minutes of a reflux episode; 49%of these were reflux-cough sequencesinvolving acidic (65%), weakly acidic(29%), and weakly alkaline (6%) reflux.Positive symptom association probabilitybetween reflux and cough was observed in10 patients (45%; 5 acidic, 2 acidic andweakly acidic, 3 weakly acidic). Thismethodology allowed for the precise determinationof temporal associations betweencough and gastroesophageal reflux andidentified a subgroup of patients who hadchronic cough associated with weaklyacidic gastroesophageal reflux.