Don't brush off your cough

Hours after a coughing fit interrupted an important speech earlier this month, British Prime Minister Theresa May posted a tweet that went viral.

It had one word - *coughs* - and was uploaded with a picture of a copy of her speech surrounded by lozenges and various herbal remedies.

Although chronic coughs are rarely life-threatening, it can pose significant distress.

A 2016 article published in the Singapore Medical Journal authored by Dr Vijo Poulose, senior consultant at the respiratory and critical care medicine at Changi General Hospital (CGH), addresses how these long-lasting coughs can be approached.

In common practice, chronic cough is defined to be a prolonged cough that lasts for more than three weeks.

In Singapore, it is one of the most common reasons for referral to a pulmonary specialist, said the article.

Coughs of different durations are common, especially when the peak flu season - usually around April to June and the end of the year - hits Singapore.

In fact, an upper respiratory tract infection (URTI) - which usually presents itself as a cough, runny nose and sore throat - is the most common ailment of patients visiting private clinics and polyclinics here, according to the Ministry of Health's Primary Care Survey 2014 published this year.

Dr Ong Kian Chung, a respiratory physician at Mount Elizabeth Hospital, recommends getting an X-ray if a cough persists for more than four weeks.

"This will rule out issues like pneumonia, tuberculosis and cancer," he explained.

If the scan is clear and there is no fever or laboured breathing, there are some common causes for the cough, stated the article.

According to unpublished local data on 200 consecutive cases of chronic cough referred to a respiratory clinic at CGH, the most common causes were:

POST-NASAL DRIP SYNDROME

Symptoms: A runny or blocked nose and an itchy throat.

Treatment: Antihistamines and a course of at least two weeks of nasal steroids if it is caused by allergies. If chronic sinusitis is suspected, the patient should be referred to an ear, nose and throat physician for further investigation.

POSTINFECTIOUS COUGH

Symptoms: Follows a viral upper respiratory tract infection and can last up to eight weeks. It is also associated with conditions including pertussis (also known as whooping cough).

Treatment: Tamiflu, an anti-viral medicine, could be prescribed after a spot test determines that the flu is caused by a virus, said Dr Ong.

GASTROESOPHAGEAL REFLUX DISEASE

Symptoms: Acid brash, heartburn and bloating.

Treatment: A therapeutic trial with acid-suppressive medication may be started.

COUGH VARIANT ASTHMA

Symptoms: A "wheezy" cough, with little or no breathing difficulty.

Treatment: Some patients respond well to standard asthma therapy, such as inhaled corticosteroids.

Dr Ong said it is important to find the cause of chronic cough as common treatments such as codeine are symptomatic.

He added: "Codeine only suppresses the cough, and habitual usage has been linked to addiction."