Air normally enters the lungs through the windpipe, down larger branching tubes (known as bronchi) and then into the smallest tubes (bronchioles).

The air passes from the bronchioles into millions of tiny air sacs (alveoli) in the lung and then into the bloodstream.

A child with bronchiolitis has

 

 

 

 

 

inflammation
If your skin or some other part of your body becomes red, swollen, hot or sore, we say it is inflamed. It means that your body is trying to protect you from germs, from something in your body tissues that can hurt you (like a thorn or sliver), or from things that cause allergies (allergens). Inflammation is part of the way the body heals an infection or injury.

 

 

 

 

 

inflamed bronchioles.

 

 

 

 

 

Source:
Juan Manuel Lozano.
Bronchiolitis.
October 2007. Clinical Evidence. (Based on October 2006 search). Available at http://clinicalevidence.bmj.com/ceweb/conditions/chd/0308/0308.jsp (accessed on 20 October 2008).

 

 

 

 

 

¹ The bronchioles become swollen and full of mucus. This makes it harder for oxygen to reach the lungs and get into the bloodstream. Your child may wheeze and breathe faster to try to get the air they need.

Bronchiolitis is caused by a virus. Respiratory syncytial virus (RSV) is the most common type. It causes bronchiolitis in 7 in 10 children with the illness. In winter, nearly all bronchiolitis is caused by this virus.

RSV is also a common cause of colds, and usually causes only mild symptoms in adults. It's spread in the air by coughing and sneezing. By the age of 2 years, almost all children have had an infection caused by RSV.

 

 

 

 

 

Source:
Navas L, Wang E, de Carvalho V, et al.
Improved outcome of respiratory syncytial virus infections in a high-risk hospitalized population of Canadian children.
Journal of Pediatrics. 1992; 121: 348-354.

 

 

 

 

 

²

For most children, an RSV infection isn't serious. But in about 1 in 5 babies and young children, the virus can infect the airways lower down and cause bronchiolitis.

In early spring, a virus called parainfluenza virus type 3 is often the cause.

 

 

 

 

 

Source:
Phelan P, Olinsky A, Robertson C.
Respiratory illness in children.
4th edition. Blackwell Scientific Publications, London, UK; 1994.

 

 

 

 

 

³ This virus also causes croup. Croup is when a child's voice box or windpipe becomes inflamed. The child usually has a "barking" cough.

Some things make it more likely that your child will get bronchiolitis. They include being:

 

 

 

 

 

Source:
U.S. National Library of Medicine.
Medline Plus: bronchiolitis.
November 2007. Available at http://www.nlm.nih.gov/medlineplus/ency/article/000975.htm (accessed on 24 November 2009).

 

 

 

 

 

⁴

The symptoms of bronchiolitis aren't severe for most young children. Your child probably won't need to go to the hospital. But the illness can become serious for babies and infants who have other lung diseases or heart diseases.

Your child is more likely to get bronchiolitis severely if he or she:

 

 

 

 

 

Source:
Navas L, Wang E, de Carvalho V, et al.
Improved outcome of respiratory syncytial virus infections in a high-risk hospitalized population of Canadian children.
Journal of Pediatrics. 1992; 121: 348-354.

 

 

 

 

 

²

You can't easily prevent your baby from getting bronchiolitis. The viruses that cause it are common and all around us. There's no vaccine available yet to protect your baby against RSV.

But if you have a cold, you can try to stop the virus from spreading. You should wash your hands often, especially before you pick up or touch your child.

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