Childhood asthma poses a number of challenges. In many asthmatic patients, the disease begins in infancy or early childhood and aeroallergen sensitization in the first 3 years of life appears to dictate later outcomes. The airway manifestations of asthma in childhood differ from those in adults and require different therapeutic approaches. Importantly, corticosteroid treatment of childhood asthma appears to have little impact on the progressive loss of lung function in a subset of patients.