Dear Doctors: I caught a cold and was sick for about a week. Now, I have a dry cough that won’t go away. It gets triggered by cold air and gets worse at night. I was in a sauna recently, and it stopped. How can I get rid of it?
Dear Reader: You’re dealing with a post-infectious cough, also referred to as a post-viral cough. This can occur in someone recovering from infection with a respiratory virus.
The trajectory of a cold, from onset to recovery, typically takes from one to two weeks. Symptoms include a stuffy or runny nose, sneezing, coughing, sore throat and post-nasal drip due to the body’s response to a virus and the immune system’s efforts to stop it.
With some people, the inflammation that accompanies a cold or the flu persists even after the viral infection has ended. This can lead to a post-infectious cough. It can last for several weeks, even up to two months, after other cold symptoms have faded.
It’s the body’s effort to ease the constricted air passages and move moist air out from the lungs.
Breathing cold air can trigger it. Cold air causes the moist and delicate tissues of the airways to contract. Also, cold air is drier than warmer air and acts as an irritant.
Lying down when your body is producing excess mucus also can trigger a dry cough because the mucus can more easily enter and irritate the airways in that position.
A post-infectious cough often can be irritating, but it is not usually dangerous.
The symptoms can be managed with over-the-counter medications and home remedies: sucking on a hard candy or cough drop to keep the throat moist and lubricated. Menthol varieties, which cause mucus membranes to shrink, will briefly slow mucus production. Honey mixed into a warm beverage also soothes irritated throat tissues.
Studies have shown the warm air of a sauna can ease the constriction associated with a persistent cough. So a sauna might bring some relief, as can a humidifier to aid moisture to the air that can give the irritated tissues of the airways a break.
Elevating your upper body with extra pillows at night can keep mucus flowing down the throat rather than into the airways.
If this cough persists more than a month, see your doctor. The immune system can get overwhelmed when dealing with a virus, and some people develop a secondary infection.
Dr. Eve Glazier and Dr. Elizabeth Ko are UCLA Health internists.
