Chronic cough: What are the causes, and how is it treated?

A cough is an automatic reflex from the body that removes mucus and irritants from the airways. While most coughs usually go away on their own, some can linger for weeks – even lasting several months.

Here, Mr Nick Hamilton, renowned consultant ENT surgeon and laryngologist based in London, provides an expert insight into a chronic cough.

How is a chronic cough defined?

A chronic cough describes a persisting cough that lasts for eight weeks or longer in adults, and for four weeks or longer in children. It can be dry or productive of phlegm.

What are the most common causes of a chronic cough?

The causes of a chronic cough are multiple. They can be broadly divided into lower airway causes, such as asthma or smoking-related chest diseases, and upper airway causes.

Within the upper airway, the most common cause for a chronic cough is believed to be allergy within the nose and throat, and reflux of stomach contents into the throat. The voice box can also become hypersensitive, and initiate coughing secondary to environmental stimuli such as cooking or smoke that would normally not induce coughing.

Coughing can also become habitual, and the act of coughing can drive inflammatory changes in the throat that create a cycle of irritation and more coughing.

Another common cause that should be considered is the use of ACE inhibitor medication for hypertension that can cause a chronic dry cough.

Can it be a sign of something serious? When should you see a doctor about a chronic cough?

While most chronic coughs turn out not to be something serious, serious health conditions can cause a chronic cough. It is therefore advisable to seek medical attention if you have a chronic cough to exclude a serious cause.

Which tests are usually performed to establish the cause of a chronic cough?

Tests are usually guided to identify the underlying cause. These can be initiated either by a respiratory physician or an ENT doctor.

Respiratory physicians focus on lower airway causes, and may perform imaging of the chest with an x-ray or a CT scan. Tests to look for reactive airway disease, such as lung function testing, are also useful.

In contrast, ENT doctors will examine the upper airway with a flexible endoscope to look for signs of allergy and to assess for signs of acid reflux. This test can also exclude lesions and problems with vocal cord movement that can cause a chronic cough. ENT doctors may also request allergy tests to support the diagnosis of upper airway allergy, and may consider referral to a gastroenterology specialist for assessment of acid reflux in certain circumstances.

How is a chronic cough treated?

A chronic cough is treated by addressing the underlying cause.

Within the upper airway, this can involve the use of nasal steroid and saline antihistamines, and the use of alginate liquids to control acid reflux. Within the lower airway, asthma inhalers may be given.

A number of cases are resistant to treatment, especially if there is a good history of hypersensitivity within the throat. These patients often benefit from cough control therapy to help overcome the urge to cough which is driving part of the sensitivity. If this does not work, medication such as amitriptyline can be given to try and reduce sensitivity.

In certain circumstances, an injection of local anaesthetic and steroid can be given to block the nerve that provides sensation to the voice box. This is particularly helpful if the irritation that is driving the cough is felt on one side around the voice box.

Mr Nick Hamilton is a highly distinguished consultant ENT specialist with over 15 years’ experience.

If you require expert assessment and treatment for a chronic cough, do not hesitate to book an appointment with Mr Hamilton via his Top Doctors profile today.