Because postinfectious cough is so common, doctors have long worked to determine how many people have a cough that persists after their other symptoms go away. Those estimates vary among studies. One small study in Japan found that of people who have a sub-acute and chronic cough, 12% resulted from a respiratory tract infection.
When it comes to COVID-19, the best evidence to date shows that only 2.5% of the people who have gotten it have also developed a chronic cough after infection. That number may seem small, but it translates to a lot of people coughing, given that the U.S. has more than 280,000 new cases of COVID-19 per week, as of early this month. The actual number, though, is unclear because the studies that look at postinfectious cough are often small and only account for the people who got COVID-19 and showed up in their doctor’s office or in a telehealth visit for evaluation.
No Simple Fix
The American College of Chest Physicians and the European Respiratory Society have published guidelines to help clinicians navigate these uncertainties and the dearth of data available on the diagnosis and treatment of coughing. Although the U.S. guidelines were published in 2006, they still represent the best evidence available for clinicians and their patients.
About half of patients recover from their cough without any treatment. For those who don’t, the limited data available suggests that inhalers, steroids, narcotics and certain over-the-counter medications may provide relief for some people.
In adults, the evidence for the efficacy of various treatments is mixed and limited. In my practice, I often prescribe a non-narcotic cough suppressant called benzonatate, sold under the brand name Tessalon Perles. It works by numbing the nerves in the lungs and airways, calming the cough reflex. Data for treatments in children is equally lacking, and studies have shown that over-the-counter cough suppressants and antihistamines were no more effective than a placebo.
Home remedies can also play an important role for some patients. Many people swear by honey, and there is some limited supporting evidence behind its benefits. One trial showed that honey was more effective at soothing a cough than a placebo over a three-day period.
When in Doubt, Ask a Doctor
Being worried about a persistent cough is understandable – a quick Google search can present plenty of reasons to worry. Though not a very satisfying answer, most coughs really will eventually resolve on their own. However, if you lose weight rapidly, cough up blood, have night sweats or produce lots of sputum, you should talk to your primary care provider. In rare cases, sub-acute and chronic cough can be a sign of lung cancer or various forms of chronic pulmonary disease.
If you are simply nervous about it and want more information and advice, that is reason enough to check in with your doctor. After all, a cough is the reason behind millions of office visits every year.