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.

Re: Trimethoprim-sulfamethoxazole or Clindamycin for Community-Associated MRSA (CA-MRSA) Skin Infections

“…2 Lastly, a study previously published by myself and my colleague demonstrated a high treatment success rate (85%) using cephalexin among patients with skin abscesses who were undergoing I&D despite that 70% of the cultures grew CA-MRSA, which were resistant to cephalexin. 2 This finding is consistent with the findings from the study by Rajendran et al, 6 which with the authors contrasted their data.…”

Community-Associated Methicillin-ResistantStaphylococcus aureus: Epidemiology and Clinical Consequences of an Emerging Epidemic

“…This contention is supported by studies in which patients received MRSA-inappropriate antimicrobials for MRSA SSTIs and, nevertheless, did well. In 2002 to 2003 in Dallas, 58/62 (94%) children with SSTIs treated with an MRSA-inappropriate antimicrobial (i.e., antimicrobial drugs to which the cultured isolate was not susceptible in vitro) had improvement at a 1-to 6-day follow-up: 37/62 (60%) patients continued on the original drug regimen, while 21/62 (34%) patients were changed to an MRSA-appropriate agent; no difference in outcome was observed (520 (744). In 2004 to 2005, a subset of 166 outpatients attending a San Francisco wound clinic were randomized after incision, drainage, and packing of a skin abscess Ͼ2 cm in diameter to receive cephalexin or placebo.…”

Infecciones de piel y partes blandas en pediatría: consenso sobre diagnóstico y tratamiento

“…Se sugiere cefalosporina de 1 a generación, como la cefalexina (100 mg/kg/día, 4 veces al día) o TMP-SMZ+ amoxicilina. 22,[42][43][44][45] Para los pacientes que no responden al tratamiento con b-lactámicos, se recomienda la cobertura para el SARM-co con clindamicina. Dosis en pediatría bajo estudio: niños, 5 mg/kg (12-17 años), 7 mg/kg (7-11 años), 9 mg/kg (2-6 años).…”

“…Se requieren datos adicionales para definir mejor el papel de los antibióticos en este contexto. [42][43][44] Se sugiere el acompañamiento con antibióticos con cobertura del SAMR-co en aquellos casos graves o extensos o asociados a comorbilidades. 22,25 En las celulitis purulentas sin abscesos drenables, se tendrá en cuenta la cobertura contra el SAMR-co en el tratamiento empírico inicial con antibióticos, como clindamicina, TMP-SMZ, minociclina, doxiciclina, linezolid.…”