Definition: Bronchiolitis is similar to bronchitis, but is an inflammation of the small airways, the bronchioles, rather than the larger bronchial tubes. It usually affects children under the age of 2, with a peak age of 3 - 6 months.
Bronchiolitis is caused by a virus, commonly the RSV virus, and can be severe, especially in infants. It is most common in fall and winter.
Bronchiolitis symptoms such as wheezing are sometimes confused with asthma symptoms. However, the symptoms usually get better quickly and are completely gone within a week or so. (See also Bronchitis)
