 Children between the ages of 2 and 8 years inclusive who have a history of asthma are eligible for enrollment if they present to the pediatric emergency department with an asthma exacerbation that is believed would not require admission to the hospital. All eligible children will be enrolled whenever there are study personnel available after obtaining informed written consent. Children less than 2 years of age will not be enrolled as their wheezing may be due to bronchiolitis. Children will also be excluded if they have been on an oral or inhaled corticosteroid in the last week, have a history of a chronic lung disease e.g. cystic fibrosis, non-corrected congenital heart disease, are pregnant, or unavailable for follow-up. 