An Overview of Chronic Cough

Chronic cough often causing much discomfort, frustration, irritability and sleep disturbances in 10 to 20% of adults is one of the leading reasons for consultation with a physician according to a report published this month in Annals of Allergy, Asthma & Immunology, the scientific journal of the American College of Allergy, Asthma and Immunology.

Matthew A. Rank, MD, at Mayo Clinic in Rochester, MN, and his colleagues, define a chronic cough as one lasting longer than eight weeks in adults and four weeks in children.”Coughing plays an important role in the body’s defense system by clearing the airway of excess secretions and foreign bodies,” note the authors. “However, in some patients cough may be excessive and unnecessary and may lead to a general deterioration in quality of life.”From the patient’s perspective, the most prevalent problems observed in a recent survey were frustration, irritability, anger, frequent physician visits and testing, and sleep disturbances.The three leading causes of chronic cough in adults are upper airway cough syndrome (UACS, also known as postnasal drip syndrome), asthma, and gastroesophageal reflux disease (GERD). The treatment described as the most effective cough resolution involves testing for all three conditions and treating them simultaneously.”Unfortunately, less research is available in childhood cough when compared to their adult counterparts,” said co-author John Oppenheimer, M.D., UMDNJ-New Jersey Medical School, Cendar Knolls, N.J. “In one study bacterial bronchitis was identified as the most common explanation for chronic cough in children, while asthma, GERD and UACS comprised less than 10% of the diagnosis. On the other hand, in another study, asthma was found to be the most common cause of chronic cough in children, reinforcing the need for further research in identifying causes of cough in this population.”New diagnostic techniques and treatments in development may bring faster relief to cough sufferers. Measurement of exhaled nitric oxide is shown to correlate with airway inflammation for identifying asthma. A portable Aeriflux testing system has been developed that may allow easier diagnosis of GERD-associated cough.Taming the chronic cough requires a thorough evaluation. Considering the leading causes of chronic cough, authors note that allergists should be pivotal in its evaluation and management.(Source: Annals of Allergy, Asthma & Immunology : Mayo Clinic : May 2007.)