 Bronchiolitis is the most common lower respiratory infection in infants, and the respiratory condition leading to the most hospital admissions in young children. It is also probably the most common serious illness of childhood lacking evidence-based treatment. Evidence both for and against the effectiveness of corticosteroids such as dexamethasone has been published. Editorials, expert reviews, and a recent report from the Agency for Healthcare Research and Quality recommend a study such as this one. 