The purpose of this clinical trial is to evaluate 2 different antibiotics, drugs that fight bacteria, [clindamycin (CLINDA) and trimethoprim-sulfamethoxazole (TMP-SMX)] and wound care for the outpatient management of uncomplicated skin and soft tissue infections (uSSTIs) in children and adults. The study will occur in areas where community associated methicillin-resistant Staphylococcus (S.) aureus are common. S. aureus is a type of bacteria. A total of 1310 volunteers, greater than or equal to 6 months of age and adults 85 years or younger, non-immunocompromised, with uSSTIs (in particular abscess and/or cellulitis) will be enrolled in this study. Subjects will be treated with one of the following: CLINDA, TMP-SMX, or placebo (contains no medication). Volunteers will be grouped based on the presence of cellulitis or abscess, whether the abscess can be surgically drained, and its size. The subject participation duration for this study is about 6 weeks.