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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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.
