Bronchiolitis is an infection in the small breathing passages, called bronchioles, that lead to the lungs. It can be caused by many viruses, but in the winter and early spring, most bronchiolitis is the work of respiratory syncytial virus (RSV).
Of course, not every child who gets RSV will develop bronchiolitis. It typically affects children under age 2, probably because their airways are smaller and more easily blocked, and appears to be more common, Dr. Kolls says, among kids who were premature or exposed to cigarette smoke, or whose mothers have allergies or asthma. Indeed, RSV-related bronchiolitis may also set children up for asthma later on. "There's some evidence that the viruses destroy the cells that line the lungs, and when they regrow, it's thought that the new cells are more susceptible to changes in environmental conditions that make the lungs twitchy," Dr. Kolls says.
Bronchiolitis starts like a cold with a low-grade fever (below 102 degrees F.). Then it moves from the upper respiratory tract into the lower respiratory tract, the cough gets worse, and the wheezing starts.
Wash your hands and your child's, and keep him away from cigarette smoke and people with respiratory infections. If your baby was premature or has chronic lung disease or congenital heart disease, he should also get monthly injections of a medication called Synagis to prevent RSV until he's no longer at risk. Injections are given every RSV season (October to March or November to April, depending on where you live).
"One of the main reasons children end up in the hospital with bronchiolitis is because they're breathing so rapidly, they can't eat and get dehydrated," says Robert J. Giusti, MD, vice chairman of pediatrics at Long Island College Hospital, in Brooklyn, New York. That's why parents should focus on making kids feel comfortable, which in turn eases breathing. Nothing else is needed, because bronchiolitis typically clears up on its own.
Like many other respiratory ailments, bronchiolitis can lead to pneumonia, so watch your child's symptoms, and go to the ER if she has trouble breathing, seems dehydrated (cries without tears, has few wet diapers or a dry mouth), or has a bluish tint around her lips or nails.