​ It is doubtful that a day goes by in my office where no one coughs. It’s one of the most common symptoms we deal with day in and day out. Coughing is a protective reflex that helps to clear the lungs and upper airways. It is a symptom, and not a final diagnosis. There are dry coughs, wet coughs, deep coughs, light coughs, wheezing coughs, racking coughs, chronic coughs, and once in a while, whooping coughs, just to name some of the varieties. For many, it’s just a few days of a nuisance tickle. But for others, the cough just doesn’t seem to go away. Weeks or months go by, and still there is that nagging cough.
By definition, a chronic cough is typically defined as one that lasts for 8 weeks or more. What causes these persistent lingering coughs? In one study, almost half were found to have asthma and/or allergies as the cause. Often asthmatics, instead of, or in addition to, wheezing or getting short of breath, have a repetitive spasmy cough. For these folks, treating their asthma and allergies with appropriate inhalers, antihistamines, Singulair, or similar meds can bring their nagging cough under control. Likewise, allergy testing and immunotherapy can be highly effective in these situations.
Another 10% or more of persistent coughers have chronic postnasal drip (PND). This can be from chronic sinusitis or allergy as well. These folks tend to be constantly clearing their throats and “hawking up” mucous, especially first thing in the morning. Clearing these chronically inflamed or infected sinuses can be very challenging and often takes a great deal of persistence.
Chronic obstructive pulmonary disease (COPD) produces another 10% of the chronic coughers. This includes chronic bronchitis and emphysema and is most often brought about by smoking. One in twelve Americans has this disease and half don’t realize it. It can’t be cured, but can be managed. Still, the biggest help is putting down the cigarettes before the disease becomes advanced.
A trigger for yet another 10% of cough is gastroesophageal reflux disease (GERD). Here the acid from the stomach comes up the throat prompting a cough reflex. Treatment of the GERD with acid blockers and other measures will often yield substantial improvement in the cough.
Then there are medication side effects. The most common culprits are the ACE inhibitors, such as Lisinopril, a class of commonly-used blood pressure medications. They work well, but about 10% of folks on these meds develop a chronic cough or tickle in their throat that only goes away when the med is stopped.
Less common, but very important is whooping cough or pertussis. This has been called the 100 day cough, and this is no exaggeration. In infants and toddlers it can sometimes be fatal, and fully half of all infants who contract it are hospitalized. Unfortunately, by the time it has passed the “cold” stage of symptoms and shown itself for what it really is, antibiotics don’t change the course much (though they are vital to render the person non-infectious). Pertussis has been on the increase over the last couple of decades, partly due to laxity in immunization.
After certain more potent coughing illnesses there can be persistent airway inflammation that keeps the cough going after the other symptoms have passed. Air pollution or other irritant-exposure can also keep a chronic cough hanging on.
Besides these more common causes, there are rarer reasons for cough such as fungal infections, aspirated foreign bodies, cancers, cardiac asthma, habitual nervous coughs and so on.
So just saying we have a chronic cough is not enough. The real detective work comes in sifting out which of these many suspects is the actual culprit. Of course, sometimes two or more suspects are working together to allow an irritating cough to linger. At any rate, if you’ve got one of those long-running nagging coughs, get it checked out. You and everyone around you can benefit if the actual cause can be found and eliminated, or at least suppressed.
Andrew Smith, MD is board-certified in Family Medicine and practices at 1503 East Lamar Alexander Parkway, Maryville. Contact him at 982-0835