“Chronic cough that is left untreated can result in permanent lung damage,” Schultz said by email.
Bacterial infections, for example, can cause progressive damage to the lungs and eventually permanent scarring if children don’t receive proper treatment,” Schultz said. This type of infection is often the culprit of chronic wet coughs when kids don’t have asthma.

“Respiratory infections could also be an indication of an underlying lung disease not yet diagnosed,” said Dr. Lilly Verhagen, a researcher at Wilhelmina Children’s Hospital in Utrecht, the Netherlands, who wasn’t involved in the study.

Because the study only included kids treated in the ED for respiratory problems, the results might not be the same for all kids treated by primary care providers, Verhagen, said by email.

But parents should still be aware that a chronic cough needs to be checked out, Verhagen said.

“If a child has a persistent cough lasting at least four weeks after a respiratory infection that was severe enough to require a hospital visit, parents should return for physician review and consideration of underlying lung disease,” Verhagen advised.