Despite major advances in understanding the etiology and pathophysiology of asthma and the development of new therapeutic modalities to control symptoms and prevent exacerbations, effective therapies are not widely used in the pediatric health care community. Further, the long term effects and side effects of asthma medications in children, especially children under the age of 12 years, are not well understood. Much remains to be learned about the impact of asthma therapy at different ages and at different points in the natural history of the asthma in altering the progression, chronicity, or severity of the disease.