NEW ORLEANS – Both clindamycin and trimethoprim-sulfamethoxazole (TMP-SMX) were superior to placebo when used after incision and drainage for the treatment of small, uncomplicated abscesses in children and adults in a prospective, randomized, placebo-controlled study.
Further, the cure rates were similar with both antibiotics, except in subjects with a clindamycin-resistant Staphylococcus aureus isolate, in whom the cure rate was lower, Robert S. Daum, MD, of the University of Chicago reported at an annual scientific meeting on infectious diseases.
Small, uncomplicated skin abscesses are common in ambulatory settings, but the optimal treatment strategy in the era of community-acquired methicillin-resistant S. aureus has been unclear. A prior study showed that clindamycin and TMP-SMX are both of benefit in the setting of large skin abscesses. The current findings further demonstrate that they also are of benefit when used in conjunction with incision and drainage for the treatment of small abscesses.
In 786 outpatient subjects, including 505 adults and 281 children who were randomized to receive 10 days of treatment with either clindamycin, TMP-SMX, or placebo following incision and drainage, mean cure rates at the 10-day posttherapy test of cure visit were 83% in the clindamycin group, 82% in the TMP-SMX group, and 69% in the placebo group, he said, noting that the differences were statistically significant for both treatments vs. placebo.
Study participants had a single skin abscess of 5 cm or less in diameter. Those with significant comorbidity, such as diabetes, were excluded.
S. aureus was isolated from 527 subjects (67%), and methicillin-resistant S. aureus was isolated from 388 (49%).
In clindamycin-treated subjects with an S. aureus lesion, 54% with a clindamycin-resistant isolate were cured, compared with 85% with a clindamycin-susceptible isolate.
Of note, subjects without S. aureus did not do better with antibiotics vs. placebo, Dr. Daum said.
“Staph aureus matters,” he said. People who did not grow Staph aureus did not do better with placebo than with antibiotic ... incision and drainage was basically all that was needed [in those patients],” he said.
Adverse events were more common in the clindamycin group (22% vs. 11% with TMP-SMX and 12.5% with placebo), but all events were mild and resolved without sequelae, and among those who were cured initially, fewer new skin infections were noted at a 1-month follow-up visit among clindamycin recipients, compared with those who received TMP-SMX or placebo, he noted at the combined annual meetings of the Infectious Diseases Society of America, the Society of Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.
No cases of Clostridium difficile-associated diarrhea were reported among study subjects.
Dr. Daum reported having no disclosures.