Treat smaller skin abscesses with antibiotics after surgical drainage? Yes.
Daum RS, Miller LG, Immergluck L, et al; for the DMID 07-0051 Team. A placebo-controlled trial of antibiotics for smaller skin abscesses. N Engl J Med. 2017;376(26):2545-2555.
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For treatment of subcutaneous abscesses that were 5 cm or smaller in diameter, investigators sought to determine if surgical drainage alone was equivalent to surgical drainage plus systemic antibiotics. After their abscess was drained, patients were randomly assigned to receive either clindamycin (300 mg 3 times daily) or trimethoprim-sulfamethoxazole (80 mg/400 mg twice daily) or placebo for 10 days. The primary outcome was clinical cure 7 to 10 days after treatment.
Details of the study
Daum and colleagues enrolled 786 participants (505 adults, 281 children) in the prospective double-blind study. Staphylococcus aureus was isolated from 527 patients (67.0%); methicillin-resistant S aureus (MRSA) was isolated from 388 (49.4%). The cure rate was similar in patients in the clindamycin group (83.1%) and the trimethoprim-sulfamethoxazole group (81.7%), and the cure rate in each antibiotic group was significantly higher than that in the placebo group (68.9%; P<.001 for both comparisons). The difference in treatment effect was specifically limited to patients who had S aureus isolated from their lesions.
Findings at follow-up. At 1 month of follow-up, new infections were less common in the clindamycin group (6.8%) than in the trimethoprim-sulfamethoxazole group (13.5%; P = .03) or the placebo group (12.4%; P = .06). However, the highest frequency of adverse effects occurred in the patients who received clindamycin (21.9% vs 11.1% vs 12.5%). No adverse effects were judged to be serious, and all resolved without sequela.
Controversy remains on antibiotic use after drainage
This study is important for 2 major reasons. First, soft tissue infections are quite commonand can evolve into serious problems, especially when the offending pathogen is MRSA. Second, controversy exists about whether systemic antibiotics are indicated if the subcutaneous abscess is relatively small and is adequately drained. For example, Talan and colleagues demonstrated that, in settings with a high prevalence of MRSA, surgical drainage combined with trimethoprim-sulfamethoxazole (1 double-strength tablet orally twice daily) was superior to drainage plus placebo.8 However, Daum and Gold recently debated the issue of drainage plus antibiotics in a case vignette and reached opposite conclusions.9
WHAT THIS EVIDENCE MEANS FOR PRACTICE
In my opinion, this investigation by Daum and colleagues supports a role for consistent use of systemic antibiotics following surgical drainage of clinically significant subcutaneous abscesses that have a 5 cm or smaller diameter. Several oral antibiotics are effective against S aureus, including MRSA.10 These drugs include trimethoprim-sulfamethoxazole (1 double-strength tablet orally twice daily), clindamycin (300-450 mg 3 times daily), doxycycline (100 mg twice daily), and minocycline (200 mg initially, then 100 mg every 12 hours).
Of these drugs, I prefer trimethoprim-sulfamethoxazole, provided that the patient does not have an allergy to sulfonamides. Trimethoprim-sulfamethoxazole is significantly less expensive than the other 3 drugs and usually is better tolerated. In particular, compared with clindamycin, trimethoprim-sulfamethoxazole is less likely to cause antibiotic-associated diarrhea, including Clostridium difficile infection. Trimethoprim-sulfamethoxazole should not be used in the first trimester of pregnancy because of concerns about fetal teratogenicity.
Read how to avoid C difficile infections in pregnant patients