MedicalResearch.com Interview with: Gregory John Moran, MD, FACEP Emergency Medicine Dept. & Infectious Diseases Service UCLA Medical Center MedicalResearch.com: What is the background for this study? What are the main findings? Response: The bacterial etiology of cellulitis is difficult to determine because there is usually no material for culture, but streptococci are believed to be the most common etiology. Since the emergence of MRSA as a common cause of skin infections in the community, many clinicians add a second antibiotic with MRSA activity to an oral cephalosporin, such as a combination of cephalexin plus trimethoprim-sulfamethoxazole. It is unknown if there is an additional benefit to adding MRSA activity for treatment of cellulitis. This randomized, blinded trial compared cephalexin plus placebo to cephalexin plus trimethoprim-sulfamethoxazole for outpatient treatment of cellulitis without an abscess or wound. Bottom line: We did not find a benefit from addition of trimethoprim-sulfamethoxazole.