Chronic cough is a common condition that’s seen by many doctors, and in most cases, after a thorough history and exam, an answer can usually be found. However, just because a physician followed all the accepted guidelines and evidence based medicine principles to successfully address and treat a condition, it doesn’t mean that it was the right thing to do. Let me explain.
A 49 year old healthy woman presented to me with a 4 month history of chronic cough only at night. She wasn’t bothered by it, but her husband was. She had tried all the routine allergy and cough suppressing medications, with no improvement. I examined her and found that the posterior portion of her larynx was inflamed and erythematous. She had classic laryngopharyngeal reflux disease, which is responsible for most cases of chronic cough.
However, for the people that have persistent chronic cough despite aggressive medical therapy, what are your options? Increasing the dosage is one option, and changing to another brand is another. Perhaps add an H2 Blocker? Get an allergy evaluation and undergo shots? Does she have laryngeal sensory neuropathy, which would require a medication that suppresses the nervous system?
Fortunately, most people with chronic cough improve on one of the above steps, but some never do. But even if a simple PPI treatment helped, was it the right thing to do?
Upon inquiring about her life, it turns out that her husband changed jobs about 4 months ago, and he gets home much later in the evening, so they have to eat very close to bedtime. Additional relevant history includes lower jaw surgery as a teen to push back a too prominent lower jaw, and she’s peri-menopausal. She’s also gained about 10 pounds over the past few years. She normally likes to sleep on her back. Otherwise, she feels fine.
Her jaw surgery was the first clue to her problem. Upon further examination, she had a mildly arched hard palate, and she had severe dental crowding. Her tongue had small ridges on the side of her tongue. Her septum was crooked to one side and she had very flimsy nostrils. Looking at her voice box, the space behind her tongue was very narrow, even when sitting up.
What all this reveals is that her jaw is too small for her tongue. Eating later in the evening before going to sleep aggravates laryngopharyngeal reflux disease via the following mechanism: Due to gravity, her tongue will fall back partially when on her back. When you add muscle relaxation, the tongue will fall back even more and obstruct her breathing. If she just ate and had more juices lingering in her stomach, the more likely it’ll be suctioned up into her throat, causing irritation of the voice box and swelling of her tongue.
Irritation of her voice box with acid, bile, digestive enzymes or even bacteria can definitely cause a chronic cough. It can also cause impressions of her teeth on her swollen tongue. Weight gain is known to aggravate sleep-breathing problems, due to a physical narrowing of her throat. Furthermore, it’s been shown that chronic acid exposure in the throat can diminish proper function of protective chemoreceptors that help to awaken the brain and cause a swallow reflex. This is presumably to prevent aspiration. Despite all these protective mechanisms, it’s been shown that digestive enzymes and even stomach bacteria can be found in the ears or the lungs through very sensitive tests.
Having a high arched hard palate also means that the space inside her mouth is smaller than normal, and the roof of her mouth (the floor of her nose) is raised up. This causes the cartilaginous nasal septum to buckle, causing your classic deviated nasal septum. If your molars are pushed towards the middle, then even your nasal sidewalls will be pushed inwards narrowing your nasal cavity even further. Add to this the fact that people with sleep-breathing problems have extra sensitive nervous systems, and the nasal turbinates can over-react to weather changes and allergies, leading to additional swelling and congestion, causing your classic stuffy or runny nose.
Additionally, because of the vacuum effect that’s created inside the nose and the more narrow angle between the septum and the nostrils, the soft, flimsy part of the nostrils will cave in more easily. Any degree of nasal congestion can create a vacuum effect downstream in the throat, allowing the tongue to fall back easier when in deep sleep, leading to more reflux into the throat and nose.
She also underwent jaw surgery when she was much younger. Most likely, the procedure made her oral cavity slightly smaller, pushing her tongue (genioglossus–the largest upper airway dilator) backwards.
The last piece of the puzzle was her peri-menopausal status. It’s been shown experimentally that progesterone is a powerful upper airway muscle stimulant. This is one of the reasons why hormone replacement therapy or even over-the-counter progesterone creams can help some women sleep better. We know that progesterone begins to slowly drop in the early 40s. The lower your progesterone levels, the more relaxed your tongue muscles, especially when in deep sleep. This is also why some women have sore throats just before their periods, since progesterone levels drop, and sleep efficiency goes down slightly. Vacuum effects from increased obstructions and arousals lead to mild degrees of laryngeal reflex.
Since inefficient sleep can cause weight gain, it’s not surprising that she gained an extra 10 pounds. Weight gain can then aggravate sleep-breathing problems.
With this woman, having her eat much earlier, along with avoiding alcohol within 3-4 hours of bedtime (since alcohol relaxes your muscles), and trying to sleep on her side were the only recommendations that I made. I expect her to recover fully within days to weeks. Most people with these issues do improve. If her nose was stuffy to any degree, then I would address that issue more definitively. Occasionally I will give a short burst of PPIs especially if there’s significant GERD symptoms.
Notice that all the various factors added together set her up to produce a chronic cough when she started eating late all of a sudden. It’s possible that if she wasn’t going through menopause, or gained 10 pounds, or never had her jaw surgery, then her cough may not have surfaced at this point in her life.
After a few more weeks, if she doesn’t improve, then I may consider ordering a formal sleep study, in light of the fact that her father snores like a train and has cardiovascular disease.
As you can see, it’s important to look at the patient’s complaint in light of her environment, diet, family history, and life changes, in addition to picking up subtle exam findings that helps to get to the root of the problem. There’s nothing wrong with giving PPIs alone for laryngopharyngeal reflux disease, since it’s the standard of care, but just because everyone else does it, is it the right thing to do for this patient?
Steven Y. Park is Clinical Assistant Professor of Otolaryngology at the New York Eye & Ear Infirmary, and author of the book, Sleep, Interrupted: A Physician Reveals The #1 Reason Why So Many Of Us Are Sick And Tired.
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