You’re working in a busy suburban ED when a patient presents with an abscess of the forearm that’s been growing for three days. The patient denies any IV drug use, significant comorbidities, or prior abscesses. You determine that the patient has an uncomplicated (no overlying cellulitis) 4cm abscess that would benefit from I&D, which is completed with irrigation and gauze packing. The patient asks you if you think they need antibiotics…
1. The patient doesn’t need antibiotics (in addition to daily packing care).
2. The patient does need antibiotics for standard skin flora.
3. The patient needs antibiotics to cover standard skin flora, as well as the possibility of MRSA.
Hankin, A., Everett, W.W. Are Antibiotics Necessary After Incision and Drainage of a Cutaneous Abscess? Annals Emerg Med 2007 50(1), 49-51.
The authors reviewed the literature (MEDLINE, EMBASE) for English-language articles from 1966 to current, using human subjects. The initial search found 1396 articles, which were limited to five original randomized trials and one abstract dealing specifically with this question.
The results of three randomized trials, two prospective cohorts and one retrospective cohort study all suggest that antibiotics were not necessary after an appropriate I&D and packing. More importantly, significant proportions of the more recent studies had MRSA in the patient populations, and even these patients did not need antibiotics. No adverse events were noted in either treatment or placebo arms.
Of note, the abstract study of Rajendran et al enrolled 166 patients in an inner city hospital-based clinic with patients having comorbidities of diabetes, HIV and hepatitis, and a 52% MRSA prevalence. Even in this “higher risk” population, there was no difference between groups treated with or without antibiotics.
There is very little high quality evidence surrounding this field, which is mildly surprising given the prevalence of this condition in North America ED’s. The six studies with <1000 total enrolled patients do not constitute the total body of evidence for this clinical question. BEEM’s independent search identified at least three additional randomized controlled trials (Stewart 1985, Blick 1980, Rutherford 1970) of an additional 752 subjects also refuting the need for antibiotics in abscess management. No study clearly defined “abscess”. There are no comments about treatment choices when there is an overlying cellulitis.
A limited body of evidence suggests that antibiotics are not needed after I&D and packing of cutaneous abscesses, even in an era of increasingly prevalent MRSA. The current review offers no guidance on treating in the presence of overlying cellulitis. The choice to treat/not treat with antibiotics may need to be balanced between guidelines from IDSA and CDC suggesting treatment when increased MRSA risk (don’t treat otherwise), versus concerns about antibiotic misuse, increasing resistance and MRSA proliferation. Individual clinicians may also want to factor in specific patient comorbidities and history in this decision. Those at increased risk for MRSA would include household contacts of know MRSA cases, recent antibiotic use (<1 month), patients in institutional care (day care, prison) or other high risk contacts (IV drug abusers, contact sports, MSM sexual partners, native populations). One should suspect MRSA in patients with recurrent cellulitis, purulent necrotic lesions (swab them!!), and failure to resolve with beta lactams.
MRSA is now an established issue in most North American ED’s, in both urban and community hospitals. Recent studies and reviews in the New England Journal of Medicine and other EM journals highlight the prevalence and resistance issues with MRSA in the ED. If choosing to treat suspected MRSA patients, the key issue to remember is to avoid cephalexin (which doesn’t treat MRSA effectively), and to use clindamycin or trimethoprim-sulfamethoxazole + cephalexin (to cover the 10-25% strep species present).
After completing the I&D procedure and packing, you engage in a discussion with the patient, and both of you agree that antibiotics are not needed. The patient will complete the prescribed follow-up plans to ensure optimal care of this abscess. The patient also is agreeable to return to ED if anything changes or gets worse. The patient leaves satisfied with this care plan.
Suneel Upadhye, Md, MSc, is an Assistant Clinical Professor of Emergency Medicine & Clin Epi-Biostats at McMaster University