The hacking that won't go away: Vancouver doctor's new research on post-infectious cough

While the weather in Metro Vancouver has been mild this winter, the cold and flu season has been anything but.

Vancouver family physician Dr. Kevin Liang says he’s seeing a lot of patients with the same complaint: they have recovered from a respiratory illness, but they have a lingering cough.

"The idea behind a post-infectious cough – which is quite common, about a quarter of patients can get this – is that there is an inflammation cascade that’s going on between your lungs, a lot of mucus build up. And your body is just taking its time to get rid of those things," said Liang.

He and two colleagues decided to research post-infectious cough, and the best ways to treat it. Their findings were published Monday in the Canadian Medical Association Journal.

“The answer, surprisingly, is time and patience. So in almost all patients, the cough will resolve on its own around the 20-day mark. And some of the medication used to treat this cough is quite expensive and they don’t work as well,” said Liang.

Doctors know that “wait it out” is not what many patients with a lingering cough want to hear. But Liang says there is an upside to his research.

"It can also be reassuring knowing this is something that resolves on its own. You don’t need to go out to the grocery store or the pharmacy and buy an expensive medication that can have some nasty side effects when this is something your body just needs to take its time and recover,” said Liang, who added there are some red flags that could be a sign there something more serious going on, and the patients should speak to their doctor.

They include persistent fever, coughing up blood, difficulty swallowing, a tight throat and a hoarse voice. It’s also concerning if the cough has persisted for longer than eight weeks.

But for the majority of people who feel better, except for their nagging cough, Liang says you don’t have to worry about being contagious. “You’re no longer going to pass that on to someone else.”

The doctors found post-infectious cough is more of a nuisance than a danger to the patient or those around them. And in most cases, it will eventually go away.