Those of you who follow my articles know that I have written any number on the subject of cough. Cough is one of the most common complaints patients may have and is sometimes the only reason for a referral. The cause for chronic cough is often discovered and the four most common causes are upper airway cough syndrome, asthma or other lung disease, gastroesophageal reflux, and non-asthmatic eosinophilic bronchitis. There are good therapies for all of these causes and patients may have more than one of them producing their chronic cough.
Chronic cough is a source of psychological stress and can be associated with many other health complications such as cardiac dysrrythmias, vomiting and occasionally life-threatening events. It is not uncommon to have difficulty in controlling chronic cough which can be frustrating to both the patient and physician.
Recently, some researchers have found that chronic cough may result from serious neurologic dysfunction. Of course, conditions such as Parkinsonism or neurologic disorders that affect swallowing function have been identified but one investigator group has found that as much as 25% of patients with refractory chronic cough have a genetic basis for their symptoms. A discussion of the exact genetics is beyond the scope of this article but involves a gene first discovered in patients with a complicated disease abbreviated CANVAS which involves a disorder of the brain called the cerebellum.
Chronic cough needs to be thoroughly evaluated and treated but genetics may play a significant role in those unresponsive to treatment.