NEW YORK (Reuters Health) – Despite the fact that methicillin-resistant Staphylococcus aureus (MRSA) is usually isolated nowadays from purulent skin and soft tissue infections in children, treatment with an antibiotic active against MRSA doesn’t improve outcomes any more than a traditional anti-staphylococcal antibiotic.
That finding is reported in the March issue of Pediatrics by Dr. Aaron E. Chen, at Johns Hopkins University, Baltimore, Maryland, and colleagues. They note that the majority of community-associated MRSA infections in healthy, non-hospitalized children are purulent skin and soft tissue infections. Observational studies have been inconsistent regarding the advantage of treating such infections with antibiotics selected for their in vitro activity.
The team hypothesized that clindamycin (an antibiotic with high clinical activity against community-associated MRSA in the researchers’ area) would be better than cephalexin (a traditional antistaphylococcal antibiotic without activity against MRSA) for treating children with purulent uncomplicated skin and soft tissue infections not requiring hospitalization.
They randomly assigned 200 eligible children to 7 days of cephalexin 40 mg/kg per day in divided doses administered 3 times per day, or clindamycin 20 mg/kg per day also taken in divided doses 3 times per day.
The primary and secondary outcomes were clinical improvement at 48 to 72 hours and resolution at 7 days.
Wounds were treated with incision and drainage or drained spontaneously in 97% of cases. Wound cultures were obtained and demonstrated MRSA in 69% of cases. Three subjects in each arm were lost to follow-up.
Within 2-3 days, improvement or resolution of infection was seen in 94% of patients in the cephalexin arm and 97% of those in the clindamycin arm (p=0.50), the researchers report. “For the subset of subjects whose initial wound cultures grew MRSA and were not lost to follow-up (135), 9% (6 of 64) in the cephalexin arm and 3% (2 of 71) in the clindamycin arm had worsened by the 48-to-72– hour visit (p=0.15).”
Clinical resolution rates at 7 days were 97% and 94% in the cephalexin and clindamycin groups, respectively (p=0.33), according to the report.
Dr. Chen and colleagues stress that almost all the children in the study had spontaneous drainage or a drainage procedure, “the cornerstone of management of purulent infections.”
Contrary to their initial hypothesis, they conclude: “Until additional studies confirm that adjuvant antibiotics offer no benefit in the management of children with uncomplicated, purulent skin and soft tissue infections, cephalexin remains a viable empiric antibiotic choice (even in areas with a high prevalence of community associated-MRSA) in the context of management that already includes careful drainage of purulent collections, attention to wound care, and appropriate follow-up.”
Randomized Controlled Trial of Cephalexin Versus Clindamycin for Uncomplicated Pediatric Skin Infections
Pediatrics 2011; 127:e573–e580.