title: Randomized, double-blind, placebo-controlled trial of cephalexin for treatment of uncomplicated skin abscesses in a population at risk for community-acquired methicillin-resistant Staphylococcus aureus infection.
abstract: Empirical use of beta-lactam antibiotics, the preferred agents for treating uncomplicated skin and soft tissue infections, may no longer be appropriate for these infections because of the increasing prevalence of community strains of methicillin-resistant Staphylococcus aureus (MRSA). Retrospective studies, however, suggest that outcomes are good even when beta-lactams are used. We conducted a randomized, double-blind trial of 166 outpatient subjects comparing placebo to cephalexin at 500 mg orally four times for 7 days after incision and drainage of skin and soft tissue abscesses. The primary outcome was clinical cure or failure 7 days after incision and drainage. S. aureus was isolated from 70.4% of abscess cultures. Of the isolates tested 87.8% were MRSA, 93% of which were positive for Panton-Valentine leucocidin genes. Clinical cure rates were 90.5% (95% confidence interval, 0.82 to 0.96) in the 84 placebo recipients and 84.1% (95% confidence interval, 0.74 to 0.91) in the 82 cephalexin recipients (difference in the two proportions, 0.0006; 95% confidence interval, -0.0461 to 0.0472; P = 0.25). The 90.5% cure rate observed in the placebo arm and 84.1% cure rate observed in the cephalexin arm provide strong evidence that antibiotics may be unnecessary after surgical drainage of uncomplicated skin and soft tissue abscesses caused by community strains of MRSA.
authors.affiliation: Department of Dermatology, University of California, San Francisco, San Francisco, CA 94143-0807, USA.
authors.forename: Priya M
authors.initials: PM
authors.lastname: Rajendran
authors.forename: David
authors.initials: D
authors.lastname: Young
authors.forename: Toby
authors.initials: T
authors.lastname: Maurer
authors.forename: Henry
authors.initials: H
authors.lastname: Chambers
authors.forename: Francoise
authors.initials: F
authors.lastname: Perdreau-Remington
authors.forename: Peter
authors.initials: P
authors.lastname: Ro
authors.forename: Hobart
authors.initials: H
authors.lastname: Harris
mesh_terms: D000038:Abscess / Q000188:drug therapy / Q000473:pathology; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002506:Cephalexin / Q000627:therapeutic use*; D017714:Community-Acquired Infections / Q000188:drug therapy* / Q000382:microbiology / Q000473:pathology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D013203:Staphylococcal Infections / Q000188:drug therapy* / Q000473:pathology; D013207:Staphylococcal Skin Infections / Q000188:drug therapy / Q000473:pathology; D013211:Staphylococcus aureus / Q000187:drug effects*; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D002506:Cephalexin