No Antibiotics for Uncomplicated Skin and Soft-Tissue Infections
A randomized, placebo-controlled trial showed no benefit for antibiotic therapy after surgical incision and drainage of uncomplicated skin and soft-tissue abscesses.
Standard treatment for skin and soft-tissue abscesses has been incision and drainage and then use of an antibiotic (usually a β-lactam). Recent studies on antibiotic treatment of such infections have shown favorable outcomes even when methicillin-resistant Staphylococcus aureus (MRSA) was isolated and antibiotics without activity against MRSA were used. However, none of these studies were placebo-controlled.
Now, researchers have conducted a randomized, placebo-controlled trial of oral cephalexin (400 mg 4 times daily for 7 days) in 166 patients who were seen at a San Francisco clinic between November 2004 and March 2005 for uncomplicated skin infections. None of the patients had incisional wounds extending into visceral tissue, bone or joint involvement, infection of prosthetic materials or venous catheters, ischemic ulcers, toxic shock syndrome, full-thickness burn wounds or burn wounds involving >20% of body surface, penicillin or cephalexin allergy, shock, or renal insufficiency. Samples for culture were obtained during the incision-and-drainage procedure, performed at the initial visit. S. aureus was isolated from 70.4% of such cultures. Among tested S. aureus isolates, 87.8% were MRSA; among tested MRSA isolates, 93.0% were positive for Panton-Valentine leukocidin genes.
Seven days after incision and drainage, the clinical cure rate was similar between the cephalexin and placebo groups (84.1% vs. 90.5%; P=0.25). Follow-up information was available for 17 of the 21 patients with treatment failure; 11 cephalexin-group patients and 6 placebo-group patients were subsequently prescribed other antibiotics.
In an era of increasing bacterial resistance, restrictive use of antibiotics is warranted. The present findings suggest that uncomplicated skin and soft-tissue abscesses can be treated safely without antibiotics. If similar data emerge from investigations on other types of infections, we might be able to reduce antibiotic use, thus decreasing selection pressure and antibiotic-associated side effects. The incidence of MRSA infections in study participants is disturbing, even if the study population had a high risk for acquiring such infections, and the extremely high rate of MRSA with Panton-Valentine leukocidin genes is cause for concern.