Step-up Yellow Zone Inhaled Corticosteroids to Prevent Exacerbations

Inclusion Criteria: * Physician-diagnosed asthma * At least 1 exacerbation treated with systemic (oral or injectable) corticosteroids in the past 12 months * Able to perform reproducible spirometry * Current treatment with step 2 controller therapy \[low-dose ICS, leukotriene receptor antagonist (LTRA)\] OR current treatment with step 3 controller therapy \[low-dose ICS + long-acting beta agonist (LABA), low-dose ICS + LTRA, or medium dose ICS\] with a childhood Asthma Control Test (c-ACT) score of \>19, no more than 2 prednisone treated exacerbations in the past 6 months, prebronchodilator Forced Expiratory Volume at 1 second (FEV1) ≥ 80% predicted and willing to step down therapy OR controller naïve and qualifying for step 2 controller therapy \[asthma symptoms or short acting beta agonist (SABA) use \> 2 days per week or night-time awakenings due to asthma \> 2 nights per month\] * Prebronchodilator FEV1 ≥ 60% predicted * Ability and willingness to provide informed assent * For females of childbearing potential: not pregnant, non-lactating, and agree to practice an adequate birth control method. * History of clinical varicella or varicella vaccine Exclusion Criteria: * Systemic (oral or injectable) corticosteroids within previous 2-week period * Current or recent (previous 2-weeks) use of medications known to significantly interact with corticosteroid disposition, including but not limited to carbamazepine, erythromycin, phenobarbital, phenytoin, rifampin, and ketoconazole * Presence of chronic or active lung disease other than asthma * Significant medical illness other than asthma, including thyroid disease, diabetes mellitus, Cushing's disease, Addison's disease, hepatic disease, or concurrent medical problems that could require oral corticosteroids during the study * A history of cataracts, glaucoma, or any other medical disorder associated with an adverse effect to corticosteroids * History of a life-threatening asthma exacerbation requiring intubation, mechanical ventilation, or resulting in a hypoxic seizure * More than 5 prednisone treated exacerbations in the past 12 months * More than 1 hospitalizations lasting \>24 hours for asthma in the past 12 months * History of adverse reactions to ICS preparations or any of their ingredients * Receiving hyposensitization therapy other than an established maintenance regimen (On maintenance regimen for ≥ 3 months) * History of premature birth before 35 weeks gestation