Chronic Cough

What is Cough?

chronic-coughA cough is your body’s way of responding when something irritates your throat or airways. An irritant stimulates nerves that send a message to your brain. The brain then tells muscles in your chest and abdomen to push air out of your lungs to force out the irritant. An occasional cough is normal and healthy., but sometimes a cough can become a chronic condition. 

 

Constant irritation and trauma to the voice box can cause a pattern of over-reaction of the vocal folds with a cough response which is more easily triggered, and the chronic feeling of needing to cough when there isn’t actually anything to cough out.

 

There are multiple chronic cough causes which will be discussed in greater detail below by our chronic cough specialist, including the chronic cough definition.

How are coughs classified? Chronic cough vs acute cough? what is the chronic cough definition?

Coughs are usually classified according to their duration:

 

Acute: 

An acute cough typically last up to about three weeks. This cough may be dry or produce mucous, but it is usually caused by cold, flu or infection of some kind.

 

Subacute: 

Subacute coughs often last between three to eight weeks. A subacute cough can heal on its own, but patients may want to see a doctor depending on the severity of symptoms.

 

Chronic: 

This cough lasts longer than eight weeks, and is often caused by smoking, post-nasal drip, reflux or asthma. This cough can involve multiple factors and can be tougher to diagnose. Lung conditions such as chronic obstructive pulmonary disease (COPD), pulmonary fibrosis, and interstitial lung diseases can also cause a chronic cough.

What are the chronic cough causes?

Beyond smoking, which is a very common cause of chronic coughing, there are three primary chronic cough causes which are responsible for >90% of chronic coughs – postnasal drainage, acid reflux, and asthma.

 

Postnasal Drip

post nasal dripPost-nasal drainage occurs when mucous created in the nose and sinuses drains backwards into the throat, with some of it dripping onto the vocal cords. One of the vocal cords’ functions is to keep liquid out of the lungs, so they respond appropriately to this drainage by trying to cough it away. As long as phlegm from the nose and sinuses continues to drain backwards to the vocal cords, the coughing will continue. The postnasal draining that causes chronic cough is usually caused by allergy or sinus issues. A good exam of the nose, throat, and vocal cords can usually confirm the diagnosis of post-nasal drainage as the cause of the cough.

 

Acid Reflux

A chronic cough caused by reflux happens when acid from the stomach travels up high enough that it spills onto the back ends of the vocal cords. The acid irritates the vocal cords, which respond by coughing. This is often accompanied by heartburn, an acidic or sour taste in the back of your throat, or some indigestion.

 

Asthma

asthmaMild asthma can cause a consistent cough, but it is almost always associated with the usual symptoms of asthma including some difficulty breathing or wheezing. A trial of a “rescue” inhaler prescribed for mild asthma can sometimes help in the diagnosis.

 

Neurogenic cough

This is also known as sensory neuropathic cough, is a diagnosis of exclusion. It is thought that it may be due to damaged nerve endings in a person’s throat leading to “misfiring” and causing cough-provoking tickling or similar sensations. The patient may have had a chronic cough for years. In such cases, nerve medications can be used, for example gabapentin for chronic cough.

How do Allergy and Sinus Issues Cause Chronic Cough?

Any irritation inside the nose can cause drainage, which can cause coughing. Some of the most common reasons for drainage are allergies, sinus infections or a deviated septum. Other sinus problems such as enlarged turbinates can also cause excess mucous or postnasal drainage, leading to chronic cough. Often, chronic coughing is caused by a combination of these factors which can make the diagnosis difficult. As a result, most people with a chronic cough have gone for long periods of time and have seen many other doctors without finding a solution.

How does an ENT specialist decide on the chronic cough diagnosis and treatment plan?

Your ENT chronic cough specialist will perform a comprehensive chronic cough history taking from you – chronologically from the beginning of the symptoms, all the way to the current symptoms. Other history such as current medications and smoking history will also be elicited. 

 

This will be followed by a comprehensive ear, nose and throat examination which may include flexible nasoendoscopy for evaluation of the upper airways. This is a simple and quick procedure that can be done under local anaesthesia in both adults and children, and is important in assessing sinus and allergy-related chronic cough, as well as reflux-related chronic cough; following which a treatment plan can be instituted by your chronic cough specialist.

 

If a lung-related cause is suspected, imaging studies such as chest X-rays may be ordered. Other sub-specialists such as a pulmonologist (lung doctor) may also need to be involved in your care should the need arise.

What is a Treatment for Chronic Cough which is Sinus and Allergy related?

Treating the underlying condition or root cause is the best way to reduce or eliminate chronic coughing.

 

Medications

Sometimes an aggressive course of medicines, which are meant to reduce and keep down swelling or discomfort in the nose, will decrease the post-nasal drip and allow the cough to resolve. When patients with allergies are treated to reduce their inflammation and other symptoms, for example with antihistamines, this can often help eliminate the cough stemming from postnasal drainage. Sometimes more aggressive treatment of your allergies through immunotherapy is required to eliminate the drainage, allowing the cough to go away.

 

Surgery

Some patients may have sinus issues causing their ongoing cough, such as a deviated septum or inferior turbinate hypertrophy. Undergoing a simple in-office procedure to correct the issue and open up blocked sinuses can potentially fix the problem. Your ENT chronic cough specialist will be able to give you further advice on surgical solutions.

 

On occasion, a combination of treatments may need to be done in order to permanently eliminate the cough and restore quality of life.

What is a Treatment for Chronic Cough which is reflux related?

Reflux-related chronic cough is treated through a combination of dietary and lifestyle modifications, as well as medications, as follows:

  • Dietary modifications with food low in acid levels, low in fat and spice.
  • Eat frequent, small meals.
  • Lose weight.
  • Avoid the use of alcohol, tobacco and caffeine.
  • Do not eat food less than 3-4 hours before bedtime.
  • Raise the head of your bed before sleeping. Place a strong, solid object (like a board) under the top portion of the mattress. This will help prop up your head and the upper portion of your body, which will help keep stomach acid from backing up into your throat. The alternative is to sleep on more than one pillow.
  • Avoid clearing your throat unnecessarily.
  • Medications to decrease acid reflux such as histamine-2 blockers and proton-pump inhibitors can also be used in conjunction with dietary and lifestyle modifications. 
Please see our article on laryngopharygeal reflux (LPR) for further information.
What are some warning signs of chronic cough?

In people with chronic cough, certain symptoms and characteristics are cause for concern. They include:lung cancer

  • Shortness of breath
  • Coughing up blood
  • Weight loss
  • Fever that lasts longer than about 1 week
  • Risk factors for tuberculosis, such as being exposed to tuberculosis, having human immunodeficiency virus (HIV) infection, or taking corticosteroids or other drugs that suppress the immune system
  • Risk factors for HIV infection 

Please seek attention at a chronic cough specialist as soon as possible if you exhibit any of these warning signs.

What are cough suppressants and should i use them?

Cough suppressants include the following:

  • Opiate-containing medications (e.g. Codeine, Procodin / Dhasedyl)
  • Dextromethorphan

procodin dhasedylAll opiate-containing medications suppress cough because they reduce the responsiveness of the cough center in the brain. There are patients who have had chronic cough for years, and have also been on this medication for years, which can cause addiction. Codeine is the opioid used most often for cough. Codeine and other opioid cough suppressants may cause nausea, vomiting, and constipation and may be addictive. They can also cause drowsiness, particularly when a person is taking other drugs that reduce concentration (such as alcohol, sedatives, sleep aids, antidepressants, or certain antihistamines). Thus, opioids are not always safe, and doctors usually reserve them for special situations, such as cough that persists despite other treatments and that interferes with sleep.

 

Dextromethorphan is related to codeine but is technically not an opioid. It also suppresses the cough center in the brain. Dextromethorphan is the active ingredient in many over-the-counter (OTC) and prescription cough preparations. It is not addictive and, when used correctly, causes little drowsiness. Overdose can cause hallucinations, agitation, and sometimes coma. 

 

Some doctors recommend expectorants (sometimes called mucolytics) to help loosen mucus by making bronchial secretions thinner and easier to cough up. Such a treatment for chronic cough does not suppress it, and evidence indicating effectiveness of these drugs is lacking. The most commonly used expectorants are preparations that contain guaifenesin. These are not commonly used in patients with chronic dry cough. Chronic cough specialists generally do not use cough suppressants, as they merely suppress the symptoms rather than addressing the root of the issue.

What are some other treatments for chronic cough?

Steam inhalation (for example, using a vaporizer) is commonly thought to reduce cough. Other topical treatments, such as cough drops, are also popular, but there is no convincing evidence that such forms of chronic cough treatment are effective.