Bronchiolitis is one of the most common respiratory illnesses among young children. It's caused by a viral infection that affects the tiny airways in the lung called the bronchioles. As these airways become inflamed, they swell and fill with mucus which can make breathing difficult. Bronchiolitis is not the same as bronchitis which is an infection of the larger airway that typically causes health issues in adults.

What causes bronchiolitis?

Bronchiolitis is usually caused by a viral infection, most commonly respiratory syncytial virus (RSV), and is prevalent between the months of October through March. Other viruses can also cause bronchiolitis. RSV is spread by contact with an affected person’s mucus or saliva. It often spreads through families and child care centers. Exposure to cigarette smoke can also increase a child’s risk for bronchiolitis.

What are the signs and symptoms of bronchiolitis?

The early symptoms of bronchiolitis are usually the same as those of a common cold including a stuffy nose, congestion, running nose, cough and fever. These symptoms last two to three days and are followed by worsening of the cough and wheezing (high-pitched whistling noises when exhaling). Sometimes more severe respiratory difficulties gradually develop. These symptoms can lead to dehydration.

Less commonly, babies (especially preemies) may have episodes where they briefly stop breathing (called apnea) before developing other symptoms. In severe cases, symptoms may worsen quickly. A child with severe bronchiolitis may get very tired from the work of breathing and have poor air movement in and out of the lungs due to the clogging of the small airways. The skin can turn blue (called cyanosis) which is especially noticeable in the lips and fingernails.

Some babies are at risk for severe bronchiolitis. They can develop a chronic heart or lung disease or have a weakened immune system due to the illness or medicines.

What’s the treatment?

Fortunately, most cases of bronchiolitis are mild and only need supportive care at home. Antibiotics aren't useful because bronchiolitis is caused by a viral infection. Infants who have trouble breathing, are dehydrated or appear fatigued should be checked by a doctor. Those who are moderately or severely ill may need to be hospitalized, watched closely and given fluids or humidified oxygen. In very severe cases, some babies are placed on respirators to help them breathe until they start to get better.

What can we do at home?

The best treatment for most children is to make sure they have plenty of fluids to drink and they have time to rest. Additionally, a cool-mist vaporizer or humidifier in the child's room can help loosen mucus in the airway and relieve cough and congestion.

To clear nasal congestion, try a bulb syringe and saline (saltwater) nose drops. This can be especially helpful just before feeding and sleeping. Sometimes, keeping a child in a slightly upright position may help ease labored breathing. Acetaminophen or ibuprofen can be given to reduce fever and make a child more comfortable. Be sure to give the appropriate dose based on your child's weight.

Call your doctor if your child is breathing fast (especially with retraction or wheezing), vomiting, experiencing a high fever or appears very tired or lethargic. Immediate care is highly suggested if your child is having difficulty breathing and the cough, retractions, or wheezing episodes are getting worse, or if the child’s lips or fingernails appear blue.