This study seeks to compare the effectiveness of a single dose of oral dexamethasone versus 5 days of oral prednisone in the treatment of mild to moderate asthma exacerbations to prevent relapse with an unscheduled return visit to a health care provider for additional asthma treatment within 14 days. The investigators hypothesize that the two treatments will be equally effective in relapse prevention.

Dexamethasone and Prednisone are both systemic corticosteroids. The study will compare a single dose of oral dexamethasone to 5 days of oral prednisone in the treatment of asthma. Oral corticosteroids are commonly prescribed following an asthma exacerbation as it has been demonstrated that these medications prevent relapse.

Oral prednisone is the most common corticosteroid prescribed for asthma relapse prevention. The half life is around 4 hours and is typically prescribed for minimally 5 days.

The study is evaluating the efficacy of a single dose of dexmethasone. The drug's efficicacy has been shown to be longer acting and up to 72 hours. A single dose would eliminate the need for a prescription for a drug like prednisone to hopefully improve compliance.

Inclusion Criteria:

• Age 18-55yo
• History of asthma
• Requires > 1 albuterol nebulizer
• Valid phone number

Exclusion Criteria:

• declines participation
• Past allergic reaction to corticosteroids
• Use of Oral steroids in the last 2 weeks
• Pregnant
• History of COPD, pulmonary fibrosis, cystic fibrosis, or other chronic lung disease
• History of HIV
• History of CHF
• History of Diabetes mellitus
• Active chickenpox (varicella) or shingles (herpes zoster)
• Active TB
• Requires admission to the Hospital
• Requires immediate airway intervention