Patients will be enrolled in a multi-center study to prospectively evaluate outcome after treatment for an uncomplicated skin abscess. All patients will receive incision and drainage and wound cultures. Patients will then be randomized to 1)no antibiotic or 2) bacterium double strength (DS) (800/160) two tablets per oral (PO) twice a day x 7 days. This is the dose recommended for treating skin and soft tissue infections. (Ellis et al. Current Opinion in Infectious Diseases. 18(6):496-501, December 2005) Patients will then return to the emergency room (ER) on days 3 and 7 for wound repacking and evaluation. The primary outcome is clinical cure of abscess at 7 days after incision and drainage and recurrence rates within 30 days of treatment. Patients who are not improving at the following visit will then be treated with additional antibiotics or admission if needed. Data will be analyzed both by initial randomization and intention to treat. This serves as the pilot for the full placebo controlled randomized trial.

Inclusion Criteria:

• all patients age 18-55 who present to the emergency department with a skin abscess that requires incision and drainage.

Exclusion Criteria:

• patients with diabetes, HIV, cancer or other immunocompromised patients
• patients who received antibiotics within one week of presentation or were hospitalized in previous month will be excluded to minimize potential confounding variables
• pregnant and breastfeeding patients will also be excluded due to possible safety concerns with antibiotic treatment
• basic Military Trainees will also be excluded from participation
• patients with abscesses on head, face, perirectal, or periananal regions, abscesses with known tracks or fistulas to deeper structures, or abscesses requiring surgical drainage in an operating room are excluded
• patients with sulfa allergy will be excluded.