The Mystery Chronic Cough (a.k.a. habit cough, tic cough, psychogenic cough, irritable larynx syndrome)

by Dr. Christopher Chang, last modified on 1/14/12
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There are patients with a mysterious chronic dry cough (longer than 6 months) that seems to defy all explanation and resist all the usual standard treatments. Some of these patients have coughed for more than ten years resulting in frustration not only in terms of treatment, but diagnosis. Often, patients are told their cough is due to reflux, allergy, asthma, infection, aspiration, virus, etc and undergo numerous exams and studies including pulmonary function tests, chest x-rays, reflux studies, barium swallows, upper endoscopy, CT scans, MRI scans, etc. Even all medications known to cause a cough as a side effect (ie, ACE Inhibitors and Angiotensin Receptor Blockers) are removed to no avail. More often than not, all these medical studies come back normal. Furthermore, proposed treatments with antibiotics, proton pump inhibitors, allergy medications, cough suppressants, steroid inhalers, etc are not successful. Surgery may even be performed which also fails to improve the cough. Eventually, some are even told it's all in their head (psychogenic cough, habit cough, tic cough, etc) or idiopathic.

A typical patient with the chronic cough is described as follows:

Please note, a workup MUST be performed before this treatment is initiatied as laryngeal sensory neuropathy is a diagnosis of exclusion.

With careful guidance with these medications, the cough signficantly improves and even completely resolves. The medications are taken for 3 to 6+ months after which it is slowly tapered down. Of note, in certain rare situations, vocal cord dysfunction, globus pharyngeus, and chronic throat-clearing are related disorders treated in a similar manner (once reflux and other medical disorders are ruled-out or thoroughly managed).

Patients need to keep in mind that it is not unusual that a patient may have SEVERAL factors of cough as well, all of which need to be treated in order to resolve a persistent cough. For example, reflux and allergies may be present as well as laryngeal sensory neuropathy. Because this disorder results in a hypersensitized larynx, problems with reflux and allergies which ordinarily would not cause a cough in normal patients, will now cause a persistent cough. In other words, though allergy testing may reveal only mild allergies and 24 hour pH study may show reflux episodes within normal range, these "mild" problems now need to be treated aggressively along with the neuropathy. The lack of treatment for each and every known cause of cough (even if mild) is the most common reason why treatment of laryngeal sensory neuropathy fails with neuropathic medication. To reiterate... laryngeal sensory neuropathy is a hypersensitized larynx. In this hypersensitized state, even a little bit of reflux or allergies will trigger a cough which normally would not. Each and every one of these conditions need to be treated. Read more about this scenario here.

In extremely rare situations, botox injections into the vocal cords may help should the medications be found ineffective.

Of note... If it is a child with a chronic cough, there is a VERY rare disorder called PANDAS (Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcus) where strep infections can trigger motor tics including chronic cough (or throat clearing) seemingly overnight. If there is concern for this particular disorder, an evaluation with a pediatric neurologist may be warranted. Here is a link to a girl who sneezed constantly due to this disorder. Here is a New York Times article.

If you are a musician playing a wind or brass instrument... your chronic cough could be due to your instrument! Germs have been found inside such instruments that can get inhaled into your lungs causing a pneumonitis resulting in chronic cough. Read more about this here.

If laryngeal sensory neuropathy is affecting your quality of life, please contact our office for an appointment.

PLEASE HAND-BRING the most recent reports and studies listed below (show to your physicians). Even better, please MAIL the records a few weeks before your visit so they can be reviewed prior to your visit to save time.

These records are ESSENTIAL and each of these studies should be done (generally speaking, though there are exceptions) prior to determining whether you may or may not have laryngeal sensory neuropathy.

Here is an online chronic cough website that has been helpful for some people.

Watch a video lecture on this topic (Video #1 and Video #2).

References

News Article on This Topic

Dr. Chang was featured in a regional quarterly publication addressing Laryngeal Sensory Neuropathy. Click here to read the article (first 2 pages).

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