Antibiotics offer similar results for uncomplicated skin infections

Cure rates and side effects did not differ significantly between clindamycin and trimethoprim-sulfamethoxazole (TMP-SMX) for uncomplicated skin infections, including both cellulitis and abscesses, a study found.

Researchers enrolled 524 outpatients (369 adults and 155 children) with uncomplicated skin infections involving cellulitis, abscesses larger than 5 cm in diameter (smaller for younger children), or both in a double-blind, randomized clinical trial at 4 study sites. All abscesses underwent incision and drainage. Patients were randomly assigned 1:1 (264 in the clindamycin group and 260 in the TMP-SMX group) and observed for a primary outcome of clinical cure 7 to 10 days after the end of treatment.

Results appeared in the March 19 New England Journal of Medicine.

In the study, 160 patients (30.5%) had an abscess, 280 (53.4%) had cellulitis, and 82 (15.6%) had both. Staphylococcus aureus was isolated from the lesions of 217 patients (41.4%), and methicillin-resistant S. aureus was isolated in 167 (77.0%). The proportion of patients cured was similar in the 2 treatment groups in the intention-to-treat population (80.3% in the clindamycin group and 77.7% in the TMP-SMX group; P=0.52) and in the populations of patients who could be evaluated (466 patients; 89.5% in the clindamycin group and 88.2% in the TMP-SMX group; P=0.77).

Adverse event rates were similar between the groups (clindamycin, 18.9%; TMP-SMX, 18.6%), as were rates of treatment discontinuation due to adverse events (8.3% and 8.8%). The most common adverse events in the clindamycin and TMP-SMX groups, respectively, were diarrhea (9.7% and 10.1%), nausea (2.3% and 2.7%), vomiting (2.3% and 1.6%), pruritus (1.5% and 1.2%), and rash (1.2% and 0.8%). There were no cases of Clostridium difficile-associated diarrhea or treatment-associated serious adverse events. Most adverse events were mild or moderate and resolved without sequelae.

“This well-powered superiority trial did not show the superiority of either intervention,” the authors wrote. “Although it is not appropriate to claim that there are no differences on the basis of the negative result of the superiority test, important differences can reasonably be ruled out with the use of confidence intervals. Adverse-event rates with the 2 therapies were similar.”