NEW ORLEANS, LA—Trimethoprim-sulfamethoxazole (TMP-SMX) or clindamycin treatment following small abscess incision and drainage (I&D) improves outcomes, suggest findings presented at IDWeek 2016.
“Clindamycin or TMP-SMX, in conjunction with I&D, improves outcomes of subjects with a small abscess compared with I&D alone, in both children and adults,” reported Robert S. Daum, MD, FIDSA, of the Department of Pediatric Infectious Disease, University of Chicago, in Chicago, IL, and coauthors.
Cure rates for both antibiotics “exceeded placebo but were similar to each other,” the authors noted.
Among study participants with clindamycin-resistant Staphylococcus aureus, cure rates were lower, the researchers cautioned.
Small and uncomplicated skin abscesses are common but optimal treatment remains unclear “in the era of community-acquired methicillin-resistant Staphylococcus aureus (MRSA),” the team noted.
The researchers therefore undertook a multicenter, prospective, placebo-controlled, double-blind study of adult and pediatric outpatients presenting with uncomplicated skin abscesses smaller than 5cm diameter (or ≤3cm for infants <12 months and ≤4cm for children aged 1 to 8 years).
Patients underwent abscess I&D and were randomly assigned (1:1:1) to receive TMP-SMX, clindamycin, or a placebo. A total of 786 patients were enrolled in the study, of whom 36% were children and 57% were males.
“S. aureus was isolated from 527 subjects (67.0%) and MRSA was isolated from 388 (49.4%),” the authors reported. “At the 10-day, post-therapy, test of cure (TOC) visit, in the intention-to-treat population, mean cure rates among subjects receiving clindamycin (221/266, 83.1%) or TMP-SMX (215/263, 81.7%) were similar (P=0.73, n.s.) and each was greater than placebo (177/257, 68.9%; P=0.0001 and P=0.0008, respectively).”
Seven of 13 patients (54%) with clindamycin-resistant S. aureus lesions were cured and 145 of 170 patients (85%) with clindamycin-susceptible S. aureus lesions were cured.
Adverse events occurred in 22% of clindamycin-group participants, 11% of TMP-SMX group patients, and 12.5% of patients administered placebo. All of these adverse events resolved with sequelae, the team noted.
Patients who were initially cured following clindamycin treatment had fewer new skin infections than those treated with TMP-SMX or placebo, at their 1-month followup visits.