Low hanging fruit: making antibiotic treatment of skin infections less awful

I recently posted about withholding antibiotics after drainage of uncomplicated purulent skin infections. The group at Denver Health now points to another opportunity for antimicrobial stewardship when treating skin or soft tissue infections (SSTI). Believe it or not, patients admitted with SSTI do not all require treatment with vancopime (or its close relative vancopiptaz (piptamycin?)). These investigators implemented a clinical practice guideline to standardize and simplify the management of patients hospitalized with cellulitis and/or skin abscess. The guideline encouraged more judicious use of testing and imaging, avoidance of broad spectrum gram negative and anaerobic coverage, and shorter courses of therapy with earlier IV to oral transition. You can read the details here, but the guideline resulted in improvement in all areas, significant reductions in use of broad spectrum antibiotics, and no difference in clinical failure rates. The study was single center and quasi-experimental, but clearly points out an area ripe for drastic improvement in most hospitals.

The accompanying editorial by Brad Spellberg is also well worth reading, and locates the cloud in this silver lining: even after the intervention, over one-third of the patients were receiving broad spectrum gram negative active agents and almost half were still receiving broad spectrum anaerobic coverage. And yes, the investigators did exclude those patients who had complicating features (e.g. diabetes, recurrence, fasciitis, etc.) that may have justified such broad spectrum therapy. So even though the intervention was a partial success, challenges to optimizing therapy for SSTI remain.

Just drain it

Check out this article from Hopkins on treatment of uncomplicated skin and soft tissue infections (SSTI) due to MRSA…..more evidence that antibiotic therapy makes very little difference in outcome. A previous large observational study of antibiotic treatment for MRSA SSTI demonstrated a benefit to receiving an “active” antimicrobial agent, but the response rate for the group who didn’t receive active therapy was still 87% (versus 95% in the active antibiotic group).

This new randomized controlled trial was smaller, confined to children, and showed no difference in outcome between those children treated with cephalexin versus clindamycin for MRSA SSTI. Although when the investigators looked at subgroups, they did find some slight evidence for a short-term benefit:

For the subset of subjects for whom an organism was isolated from the initial wound culture and susceptibility data were known (183), 2% (2 of 111) of those who received an antibiotic with in vitro activity against the isolate versus 10% (7 of 72) of those who received an inactive antibiotic had worsened by the 48-to-72– hour visit (P=0.02).

Treatment of uncomplicated MRSA SSTI now involves a balance between the benefits of avoiding antimicrobial therapy (individual and societal) and what appears to be a very small risk for slower response to therapy. There is also the issue of whether receipt of an “inactive” antibiotic (e.g. cephalexin for MRSA) is the same thing as receiving no antibiotic (or placebo). Another recent study of managing pediatric SSTI suggests that it is.

The bottom line? Avoid antibiotic therapy in the management of purulent (i.e. drainable) uncomplicated SSTI. Incision and drainage, and good wound care, should suffice.

And as long as we’re talking about good antimicrobial stewardship, go read this JAMA piece by Jim Hughes on preserving the power of antimicrobials….