Antibiotic therapy after surgical drainage of abscesses improves cure rates, even in the presence of methicillin-resistant Staphylococcus aureus (MRSA), according to results of a recent US study.
Eighty percent of individuals given trimethoprim and sulfamethoxazole achieved clinical cure compared to 73.6 percent of patients given placebo after surgical drainage of a cutaneous abscess.
Adjunct antibiotic treatment also reduced the need for subsequent drainage (3.4 percent in the treatment group vs 8.6 percent in the placebo group), skin infections at a different site (3.1 vs 10.3 percent) and infections among household members (1.7 vs 4.1 percent) 7 to 14 days post-treatment.
There was a higher incidence of adverse events in the treatment arm, though these were mostly mild gastrointestinal problems.
“Adjunctive oral treatment with trimethoprim-sulfamethoxazole, which is inexpensive, appears to be safe, and is associated with a high cure rate of the primary lesion, offers the possibility of lower rates of costly subsequent medical visits, surgeries, and hospitalizations and of new infections among patients and their household contacts,” said the study authors.
Participants of this double-blind, randomized trial were 1,265 patients aged >12 years who presented at 5 US Emergency Departments (EDs) with uncomplicated cutaneous abscesses which were treated with drainage. Among them, 45.3 percent had wound cultures that were positive for MRSA. Participants were given a combination of trimethoprim (320 mg) and sulfamethoxazole (1600 mg) twice daily for 7 days or a placebo.
While previous small studies have shown that adjuvant therapy with trimethoprim-sulfamethoxazole helped prevent the formation of new lesions in the short-term, they were not recommended for widespread use.
“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,” said Dr. Gregory Moran, Clinical Professor of Emergency Medicine at the David Geffen School of Medicine, University of California, Los Angeles (UCLA), California, US, and one of the authors of the present study. He hoped that the results would help guide doctors in treating abscesses.
According to the authors, adjunctive antibiotics are recommended for patients with coexisting conditions such as diabetes and cellulitis and those who have infected lesions that are larger than 5 cm. In the case of this study, many participants met the criteria for the use of antibiotics, said the authors.