Smaller Skin Abscess Healing Rates May Be Improved with Course of Antibiotics

The results of a new study out of the University of Chicago show that antibiotic treatment may help improve recovery for minor skin abscesses.

Most minor abscesses are lanced and drained by a physician in an outpatient setting. The infections are usually caused by Staphylococcus aureus, “which can include the drug-resistant methicillin-resistant Staphylococcus aureus (MRSA),” according to a press release on the study. Therefore, the University of Chicago researchers posited that adding an antibiotic to the treatment regimen could improve rates of recovery.

For their study, a team of researchers led by Robert Daum, MD, a professor of pediatrics at the University of Chicago, conducted a multicenter, prospective, double-blind trial between 2009 and 2015 of 786 patients treated in the outpatient setting with abscesses. A total of 505 of the participants were adults, and 281 were children. Four hundred forty-eight of the participants were male. The “patients were stratified according to the presence of a surgically drainable abscess, abscess size, the number of sites of skin infection, and the presence of nonpurulent cellulitis,” according to the study. Those participants who had an abscess diameter of 5 cm or smaller were enrolled.

A total of 388 patients had MRSA isolates, and 527 had Staphylococcus aureus. Two antibiotics, clindamycin and trimethoprim-sulfamethoxazole (TMP-SMX), have been shown to be effective against MRSA infections. As such, after completing incision and draining on all of the patients, “one-third of the patients were prescribed clindamycin. Another third received TMP-SMX. The remaining one-third received a placebo (inactive drug).” Clinical cure 7 to 10 days after the end of treatment was the primary outcome.

The results of the study showed that after 10 days of therapy, “the cure rate among participants in the clindamycin group was similar to that in the TMP-SMX group (221 of 266 participants [83.1%] and 215 of 263 participants [81.7%], respectively; P = .73), and the cure rate in each active-treatment group was higher than that in the placebo group (177 of 257 participants [68.9%], P<.001 for both comparisons).”

In addition, “among the participants who were initially cured, new infections at 1 month of follow-up were less common in the clindamycin group (15 of 221, 6.8%) than in the TMP-SMX group (29 of 215 [13.5%], P = .03) or the placebo group (22 of 177 [12.4%], P = .06).”

According to the researchers, mild or moderate diarrhea and nausea were the most common side effects.

Kenneth Bromberg, MD, a professor of clinical pediatrics with the Icahn School of Medicine at Mount Sinai in New York City, who was not involved in the study, stated in the press release that the findings of the study, “will cause those physicians who only use drainage to reconsider [that position]. I think doctors should adopt the use of antibiotics in most patients based on this study.” In addition, Dr. Bromberg remarked that most practitioners are already following this practice in patients who have diabetes or immune issues.

The study was funded by the US National Institutes of Health and has a ClinicalTrials.gov number of NCT00730028.