Management of Skin Abscesses. NEJM review article

From this week's NEJM... some guidelines in how to treat this common problem.

Clinical Pearls

How does ultrasound enhance the diagnostic accuracy of physical exam in detection of an abscess?

Studies in adults and children suggest that soft-tissue ultrasonography enhances the diagnostic accuracy of abscess detection and alters plans for management that are based on physical examination alone. In a prospective study involving 126 adults with clinical cellulitis in whom an emergency physician believed an abscess was not obvious on physical examination but might be present, ultrasonography resulted in a change in projected management in 56% of the patients. Ultrasonographic images showed fluid collection that was consistent with an abscess in half these patients, and approximately 80% of patients who underwent additional diagnostic testing had pus or other fluid collections. Management was also altered in three quarters of patients in whom drainage had been thought to be required on the basis of physical examination alone (e.g., it was decided that drainage was not needed, that further imaging was required, or that the incision and drainage approach should be altered).

What are the general principles of incision and drainage of an abscess in the office setting?

Many abscesses can be managed in the office setting by a general practitioner. Large, complex, or recalcitrant abscesses, especially those over sensitive areas (e.g., the hands or face), should prompt consideration of referral to a specialist or an emergency department, where additional resources can be brought to bear. The primary treatment for skin abscesses is incision and drainage. A single incision is made; the incision should be long enough to ensure complete drainage, allow lysis of loculations with a blunt instrument, and follow tension lines in order to minimize scarring. A common mistake is to make an incision that is not deep enough to reach and fully drain the abscess cavity. Particular care should be taken before incising the skin over critical structures, such as major vessels and nerves. A recent small study among adults suggested that many abscesses can be adequately drained through a short incision (median length, 1 cm).

Q. According to the authors, when should primary closure of drained abscesses be considered?

A. Primary closure of drained abscesses should be considered for large incisions (i.e., >2 cm), especially over cosmetically important areas, and may warrant referral to a specialist. Primary closure should not be performed in patients with infected sebaceous cysts or lymph nodes or similar disease processes, patients in whom the adequacy of drainage is in doubt, and patients who have systemic infection or a strong risk factor for systemic infection (e.g., diabetes).

Q. When is antibiotic treatment recommended in addition to incision and drainage of an abscess, and in such cases, what is the appropriate antibiotic regimen?

A. The Infectious Diseases Society of America (IDSA) recommends systemic antibiotic treatment, in addition to incision and drainage, for patients with severe or extensive disease (e.g., multiple sites of infection) or with rapid disease progression and associated cellulitis, signs and symptoms of systemic illness, associated coexisting conditions or immunosuppression, very young age or advanced age, an abscess in an area difficult to drain (e.g., face, hands, or genitalia), associated septic phlebitis, or an abscess that does not respond to incision and drainage alone. Empirical antibiotic therapy, if prescribed, should have in vitro activity against community-associated MRSA. Most patients who have a minor abscess can be treated as outpatients with inexpensive oral antibiotics. TMP-SMX, clindamycin, and tetracycline have been shown to have in vitro activity against 94% to nearly 100% of more than 300 MRSA isolates tested in a 2008 U.S. emergency department–based surveillance study. Other antibiotics with anti-MRSA activity that have been approved by the Food and Drug Administration for the treatment of skin and soft-tissue infection include vancomycin, linezolid, daptomycin, telavancin, tigecycline, and ceftaroline.

Worth emphasizing:
1) Incision and drainage is the primary treatment for skin and soft tissue abscess.
2) Consider referring if abscess is located in complicated or cosmetically sensitive areas.
3) Antibiotics ONLY for complicated or high risk cases.
4) Cheap antibiotics are just fine.

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In another note… I want to thank my new friends at Cho Ray Hospital in Ho Chi Minh City for hosting such a great event. I look forward to next year’s conference.