New Study Could Alter the Way EDs Treat Abscesses in Age of MRSA

October 5th, 2016

LOS ANGELES – If you think surgical drainage alone is sufficient for treating abscesses, a new study might change your view.

A study published recently in the New England Journal of Medicine finds that using trimethoprim-sulfamethoxazole in addition to drainage improves recovery.

UCLA researchers point out that their discovery is especially important now that community-acquired methicillin-resistant Staphylococcus aureus (MRSA) has been the most common cause of skin infections in the United States since 2000.

“We found that adding in a specific antibiotic to the medical treatment also resulted in fewer recurring infections, fewer infections in other places on the body and fewer people passing on the infection to other members of the household,” explained lead author David Talan, MD. “This translates into fewer medical visits and reduced healthcare costs.”

Background information in the article notes that U.S. emergency department visits for skin infections nearly tripled from 1.2 million to 3.4 million between 1993 and 2005, with most of the increase due to a greater incidence of skin abscesses.

“Traditional teaching has been that the only treatment needed for most skin abscesses is surgical drainage — and that antibiotics don’t provide an extra benefit,” added co-author Gregory Moran, MD, in a UCLA press release. “Our findings will likely result in patients more often being recommended to take antibiotics in addition to having surgical drainage when they get a skin abscess.”

For the study, researchers examined treatment for more than 1,200 patients at five hospital EDs in Los Angeles, Baltimore, Kansas City, Philadelphia, and Phoenix to determine whether trimethoprim–sulfamethoxazole (at doses of 320 mg and 1600 mg, respectively, twice daily, for seven days) would be superior to placebo in outpatients older than 12 years of age with uncomplicated abscess treated with drainage. The median age of the participants was 35, and 45.3% had wound cultures that were positive for MRSA.

The primary outcome was defined as clinical cure of the abscess, assessed 7 to 14 days after the end of the treatment period.

Results for the modified intention-to-treat population indicate that clinical cure of the abscess occurred in 80.5% of participants in the trimethoprim–sulfamethoxazole group vs. 73.6% in the placebo group. In the per-protocol population, meanwhile, clinical cure occurred in 92.9% in the trimethoprim–sulfamethoxazole group vs. 85.7% in the placebo group.

“Trimethoprim–sulfamethoxazole was superior to placebo with respect to most secondary outcomes in the per-protocol population, resulting in lower rates of subsequent surgical drainage procedures (3.4% vs. 8.6%; difference, −5.2 percentage points; 95% CI, −8.2 to −2.2), skin infections at new sites (3.1% vs. 10.3%; difference, −7.2 percentage points; 95% CI, −10.4 to −4.1), and infections in household members (1.7% vs. 4.1%; difference, −2.4 percentage points; 95% CI, −4.6 to −0.2) 7 to 14 days after the treatment period,” study authors point out.