Diagnosis and treatment of chronic cough due to gastro-esophageal reflux disease and postnasal drip syndrome

Gastro-esophageal reflux disease (GERD) and postnasal drip syndrome (PNDS) are common causes of chronic cough. In patients with normal chest radiographs, GERD most likely causes cough by an esophageal-bronchial reflex. When GERD causes cough, there may be no gastrointestinal symptoms up to 75% of the time. While 24-h esophageal pH monitoring is the most sensitive and specific test in linking GERD and cough in a cause and effect relationship, it has its limitations. There is no general agreement on how to best interpret the test and it cannot detect non-acid reflux events. While some patients improve with minimal medical therapy, others require intensive regimens. Surgery may be efficacious when intensive medical therapy has failed. Because there are no pathognomonic findings of PNDS, the diagnosis is inferential and is based upon a combination of clinical findings, the results of ancillary testing, and the response to specific therapy. Specific therapy depends upon the rhinosinus disease(s) causing the PND. A common error in managing PNDSs is to assume that all H(1)-antagonists are equally efficacious. The second-generation, relatively non-sedating H(1)-antagonists have been found to be less effective than the first-generation agents in treating cough due to non-histamine-mediated PNDSs.