Objective: To review the literature on the most common causes of chronic cough.
Methods: MEDLINE was searched (through May 2004) for studies published in the English language since 1980 on human subjects using the medical subject heading terms "cough," "causes of cough," and "etiology of cough." Case series and prospective descriptive clinical trials were selected for review. Also obtained were any references from these studies that were pertinent to the topic
Results: Upper airway cough syndrome (UACS) due to a variety of rhinosinus conditions, previously referred to as postnasal drip syndrome, asthma, nonasthmatic eosinophilic bronchitis (NAEB), and gastroesophageal reflux disease (GERD) are the most common causes of chronic cough. Each of these diagnoses may be present alone or in combination and may be clinically silent apart from the cough itself.
Conclusion: In the absence of evidence for the presence of another disorder, an approach focused on detecting the presence of UACS, asthma, NAEB, or GERD, alone or in combination, is likely to have a far higher yield than routinely searching for relatively uncommon or obscure diagnoses.