Understanding the Etiology and Pathophysiology of Chronic Cough and its Impact on Patient’s Quality of Life

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Dr. Dicpinigaitis:
Hello, my name is Dr. Peter Dicpinigaitis. I'm a professor of medicine at the Albert Einstein College of Medicine and director of the Cough Center at Montefiore Medical Center in New York. Our presentation today is titled, Understanding the Etiology and Pathophysiology of Chronic Cough with its Impact on the Patient's Quality of Life. In most basic terms, cough is a simple reflex where there is a peripheral afrin signal initiated in the airway that then travels through the vagus nerve to the brain stem to initiate the motor event of cough. What's not simple is the fact that there are many different possible peripheral triggers that can induce that afrin signal in the airway to induce the motor event of cough.

There are some common etiologies of chronic cough, and we, as physicians, when we meet a patient with a chronic cough, need to do a thorough evaluation looking for reversible, treatable causes of chronic cough, which are usually effective and successful. So, if we have a patient who's a non-smoker, not on an ACE inhibitor medication, and has a normal or stable chest x-ray, then it's most likely that the cough is due to one or more of three main etiologies. Those being number one, upper airway cough syndrome, also known as postnasal drip syndrome. Number two, asthma. And number three, reflux or GERD.

Although this could be the topic of an entire lecture, just very briefly, it's important that we effectively and thoroughly evaluate for underlying treatable conditions with the proper medications given at the proper doses and proper durations to rule out these top three etiologies of cough. So, for example, for upper airway cough syndrome, I found that an oral first-generation antihistamine is most effective, for asthma-inhaled steroids, but sometimes oral steroids may be needed to evaluate for a response to cough. And for reflux, high-dose acid suppression therapy with a twice-daily PPI may be needed in addition to anti-reflux lifestyle measures.

However, even after we perform a very thorough evaluation with diagnostic therapeutic treatment trials for all known underlying causes of cough, some cough will still persist. And when we get to this stage, we call that cough refractory chronic cough.

Unfortunately, refractory chronic cough can have a tremendous effect on a patient's quality of life cause by the time that diagnosis is made the patient may have been coughing for months, if not years or decades. And it's quite common, unfortunately, for patients to suffer anxiety and depression from being socially isolated because of their cough. And with physical discomfort such as chest discomfort, musculoskeletal discomfort, throat discomfort, interference with sleep, and, in women, specifically, cough-induced urinary incontinence is very common.

So, as one example, we did a study some years ago looking at patients presenting to our cough center for evaluation of cough, and we evaluated these patients with a clinical depression scale, and we found that, in fact, 53% of the patients presenting to our chronic cough center tested positive on this clinical depression scale.

We recently published a study last year looking at over 200 consecutive women presenting to our chronic cough center, and we found that, in fact, 62% of those women suffered from cough-induced stress urinary incontinence. So one really can underestimate the tremendous quality of life effect a chronic cough can have.

So, to conclude, chronic cough is a very common symptom that, in many cases, can be treated if reversible causes are identified. However, refractory chronic cough, a cough that does not respond to any of our treatment trials, can cause tremendous quality of life issues because, at the present time, we don't have any good, safe effective medications for refractory chronic cough. And let's keep in mind that refractory chronic cough takes a tremendous toll in terms of quality of life, not only in the patients, but, as you can imagine, for the patient's spouse, other family, and coworkers. Thank you very much for your attention.

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