Bronchiolitis is swelling and mucus buildup in the smallest air passages in the lungs (bronchioles), usually due to a viral infection.
Bronchiolitis usually affects children under the age of 2, with a peak age of 3 - 6 months. It is a common, and sometimes severe illness. Respiratory syncytial virus (RSV) is the most common cause. More than half of all infants are exposed to this virus by their first birthday.
Other viruses that can cause bronchiolitis include:
You can catch the virus if you come into direct contact with nasal fluids or airborne droplets from someone who has the illness. This may happen if the person sneezes or coughs near you.
Bronchiolitis is seasonal and appears more often in the fall and winter months. It is a very common reason for infants to be hospitalized during winter and early spring.
Risk factors for bronchiolitis include:
Some children may have few or minor symptoms.
Bronchiolitis begins as a mild upper respiratory infection. Over a period of 2 - 3 days, the child develops more breathing problems, including wheezing and a "tight" wheezy cough.
The health care provider will perform a physical exam and listen to the lungs. This may reveal:
Tests that may be done include:
Sometimes, no treatment is necessary. Antibiotics do not work against viral infections. Most medications do not help treat bronchiolitis.
Supportive therapy can include:
Children in the hospital may need oxygen therapy and fluids given through a vein (IV).
Rarely, antiviral medications, such as ribavirin, may be used to treat extremely ill children.
Usually, the symptoms get better within a week. Breathing difficulty usually gets better by the third day.
Call your health care provider immediately, or go to the emergency room if the child with bronchiolitis:
Most cases of bronchiolitis are not easily preventable because the viruses that cause the disorder are common in the environment. Careful attention to hand washing, especially around infants, can help prevent the spread of respiratory viruses.
Family members with an upper respiratory infection should be especially careful around infants. Wash your hands often, especially before handling the child.
At this date, there is no RSV vaccine available. However, there is an effective product, called palivizumab (Synagis), for infants who are at high risk of developing severe disease from RSV. Ask your child's doctor whether this medication is right for your child.
Watts KD, Goodman DM. Wheezing, bronchiolitis, and bronchitis. In: Kliegman RM, Behrman RE, Jenson HB, Stanton BF, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 383.
American Academy of Pediatrics Subcommittee on the Diagnosis and Management of Bronchiolitis. Diagnosis and management of bronchiolitis. Pediatrics. 2006;118:1774-1793.
Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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