Coughing is a reflex of the respiratory system intended to protect the lungs from foreign bodies or irritants trying to enter the respiratory tract. It is caused when the above substances irritate sensory nerves located in the larynx, trachea, large bronchi, lung, but also in places outside the lungs such as the nasopharynx, the external auditory canal of the ear, the pleura, the pericardium, the diaphragm, the esophagus and stomach.

“Cough, based on its duration, is divided into acute, when it lasts from a few minutes to a few days (e.g. food inhalation, acute infections) and into chronic cough, when it lasts for more than 8 weeks in adults and more than 4 weeks in children” points out Mr. Dimitrios Vassos Pulmonologist – Tuberculologist,
Research Fellow Metropolitan General.

He adds that “chronic cough is a global problem as it is estimated to occur in 5-10% of adults and is more common in people over 60, mainly women. Chronic cough has serious effects both on the patient himself and on those around him. The patient has difficulty speaking and exercising, sleep disturbance and exhaustion, while severe coughing can cause vomiting and loss of urine. At the same time, it creates concern for the patient’s surroundings, his family, friends and colleagues, and in combination with anxiety about an underlying serious illness, it can lead to social isolation and the appearance of depression.”

Causes of chronic cough

Chronic cough is caused by many conditions such as:
• Use of tobacco
• Chronic bronchitis caused by smoking
• Undiagnosed or unregulated bronchial asthma
• Chronic infections such as tuberculosis and mycosis
• Bronchiectasis created by repeated respiratory infections
• Intermediate respiratory diseases such as pulmonary fibrosis and sarcoidosis
• Lung cancer that we think of mainly if we have a change in the characteristics of the chronic cough in smokers

But the cough can also be due to diseases that are not located in the lungs. Among the most common are:
• Diseases of the nose, sinuses (allergic rhinitis, postnasal drip), pharynx and larynx
• Gastroesophageal reflux and aspiration of stomach contents
• Diseases of the pleura, such as pleurisy, can irritate the nerves in the pleura and cause coughing
• Also heart diseases, such as heart failure, in which the patient coughs when lying down and forces him to get up from a sitting position
• Sometimes the cough can also be due to drugs that the patient is taking for another reason, such as some drugs to treat arterial hypertension. It occurs in about 15% of these patients and is dry and persistent mainly during the night hours
• Finally, in a group of patients the causes of cough are considered psychogenic

Diagnostic approach

History, clinical examination, and chest X-ray are essential in the investigation of chronic cough. A good history will usually lead in the right direction for investigating the cause of it. “Points that interest us are the time of onset of the cough, if it is affected by the seasons of the year, if there is something that causes it or relieves it, if the patient smokes or works in areas with irritating fumes, dusts or chemicals, if he chokes when swallowing , if he coughs during the night, if the cough subsides on sitting or standing and if there is phlegm, what quantity and quality.

A chest X-ray helps rule out underlying causes of cough and is a key step in the investigation. A CT scan is not always considered necessary. But it is necessary if we have something pathological in the x-ray or when we suspect interstitial diseases, bronchiectasis or malignancy.

Another useful tool is spirometry to help detect airway obstruction and distinguish between bronchial asthma and Chronic Obstructive Pulmonary Disease (COPD). If there is a strong suspicion of increased bronchial hyperreactivity that did not become apparent on spirometry, the patient may undergo a challenge test with a specific drug (metacholine or histamine).

Bronchoscopy can aid in diagnosis or even treatment in cases where aspiration of a foreign body or malignancy is suspected. But it has a central role in the diagnosis of other diseases such as interstitial lung diseases, infections and sarcoidosis which can also cause a chronic cough”, emphasizes the specialist doctor.

An otolaryngological examination is also an important step in order to rule out upper respiratory diseases that can manifest with a chronic cough or to identify conditions such as postnasal drip or gastroesophageal reflux. For the latter, in specific cases, a test with esophageal manometry is applied.

Treatment

“In patients whose cough seems to show asthmatic elements, the use of inhaled drugs (corticosteroids, alone or in combination with bronchodilators) for 2-4 weeks is recommended. Antacid drugs (proton pump inhibitors, H2 antagonists) appear to benefit patients with symptoms or findings of GERD. Antibiotics are a solution only in case of specific inflammation (eg tuberculosis) or contamination of bronchiectasis by specific microbes. In chronic cough that does not respond to treatment, neuromodulating drugs help to reduce the intensity of the cough and improve the quality of life. Medicines such as morphine reduce bronchial hyperreactivity, the frequency and intensity of cough, while recently new agents are being tested for patients with chronic persistent cough who do not respond to the above preparations”, concludes Mr. Dimitrios Vassos.