Bronchiolitis is a childhood disease that affects the lungs. It occurs when a virus enters the breathing system. The virus causes the tiny airways in the lungs to become swollen. As a result, a thick fluid called mucus collects in the airways. This makes it hard for air to flow freely in the lungs.

Usually, the infection goes away after 7-10 days. Some children show very mild symptoms. In others, the disease can be severe. Older children are less at risk. If they get bronchiolitis, they don’t get as sick as younger children.


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This infection is caused by several kinds of viruses. It easily spreads from person to person in the same way a common cold does. This most often happens when an infected person coughs or sneezes. Droplets of moisture are released into the air. When a noninfected person breathes the air they can become infected.

Risk Factors

Bronchiolitis can affect anyone, but it most often strikes:

  • Children under the age of two, especially between 3-6 months old
  • During the winter months
  • Adults most at risk are those who are:
    • Immunocompromised
    • Exposed to toxic fumes
  • Children most at risk are those who:
    • Were never breastfed
    • Were born prematurely
    • Are exposed to tobacco smoke
    • Are often in groups of children (as in day care) or live in crowded conditions


Symptoms of bronchiolitis occur in two stages:

During the first 2-3 days the child will probably have a:

  • Runny or stuffy nose
  • Slight fever

During the next 2-3 days, the symptoms increase to include:

  • Cough (dry)
  • Fever
  • Sneezing
  • Rash
  • Red eyes
  • Fast rate of breathing
  • Difficulty breathing
  • Wheezing (making a whistling noise during breathing)
  • Bluish color in the skin, especially around the lips or nails
  • Poor feeding
  • Restlessness


To diagnose bronchiolitis, the doctor may do one or more of the following:

  • Listen to the child’s lungs to check for abnormal breathing, such as wheezing
  • Chest x-ray to check for swelling in the airways and signs of pneumonia (severe case)
  • Sample mucus from nose or throat to test for the virus that may be causing the infection
  • Blood test to determine the level of oxygen in the blood
  • Blood test for complete blood count


There is no medication to cure viral infections. Doctors sometimes prescribe corticosteroids. These may help to reduce swelling and mucus in the airways. But, there is limited evidence showing its benefits.

This infection usually clears on its own after a week or ten days. There are several ways to make the child more comfortable while he or she is experiencing symptoms:

  • Have the child drink clear liquids.
  • Use a vaporizer in the bedroom.
  • When the child is coughing or having difficulty breathing, steam the bathroom using hot water from the shower. Sit in there with the child.
  • Advise smoking parents to not smoke in front of child.
  • Use acetaminophen (eg, Children’s or Infant’s Tylenol) if a fever is present.

In severe cases, medical treatment may be needed. The doctor will check for dehydration and pneumonia. The doctor will also make sure the child is getting enough oxygen. Medications may be as well.

Call the doctor if the child:

  • Is vomiting and can’t keep liquids down
  • Is breathing very fast (more than 40 breaths in one minute)
  • Has bluish skin, especially around the lips or on the fingertips
  • Has to sit up to breathe
  • Was born prematurely or has a history of heart disease
  • Appears dehydrated


Bronchiolitis can spread easily from one person to another. Children should be kept home until they are well to prevent giving the infection to others. There is no vaccine to prevent bronchiolitis. There are medications that may lessen the risk of infection by respiratory syncytial virus (RSV) . RSV is a virus which causes more than half of all cases of bronchiolitis. This medication is usually given to high-risk babies.

Proper handwashing habits can help to prevent the spread of illness. Make sure to wash your hands before touching a baby or after being in contact with an infected one.