Patients age 3 months to 17 years presenting to a pediatric Emergency Department (ED) with an uncomplicated skin abscess that required surgical drainage were randomized to receive 3 or 10 days of oral trimethoprim-sulfamethoxazole. Patients were evaluated 10 to 14 days later to assess for cure. Patients were contacted 1 month later to determine if they had developed another skin infection. Outcomes were also stratified by methicillin-resistent staphylococcus aureus (MRSA) and methicillin-sensitive staphylococcus aureus (MSSA).