Sour Milk: Antibiotic Coverage For a Breast Abscess
Clinical scenario:
Your patient is a middle-aged female who was brought in from home for altered mental status. As EMS is moving her over to the stretcher, they say: "this lady has some kind of infection on her breast ... I saw it when I went to do her EKG". The patient is febrile to 39.3, tachycardic in the 120’s, but maintaining a blood pressure of 150’s/80’s. She has a large, right- sided breast abscess with some spontaneous drainage. Clearly, this patient has severe sepsis and she needs IVF, antibiotics, and source control.
Contributed by Maia Dorsett, PGY-3
Your patient is a middle-aged female who was brought in from home for altered mental status. As EMS is moving her over to the stretcher, they say: "this lady has some kind of infection on her breast ... I saw it when I went to do her EKG". The patient is febrile to 39.3, tachycardic in the 120’s, but maintaining a blood pressure of 150’s/80’s. She has a large, right- sided breast abscess with some spontaneous drainage. Clearly, this patient has severe sepsis and she needs IVF, antibiotics, and source control.
Clinical Question:
What is the most appropriate antibiotic choice for coverage of a breast abscess? Obviously, the patient needs an I&D, but in the meantime, what typically is growing in there? Should anaerobic coverage be routine?
What is the most appropriate antibiotic choice for coverage of a breast abscess? Obviously, the patient needs an I&D, but in the meantime, what typically is growing in there? Should anaerobic coverage be routine?
The Literature:
There
are several articles that address culture results from breast abscesses
in the era of community acquired MRSA. Here are two:
One
article [1] reports the culture results of 189 drained breast
abscesses from both lactating (LA) and non-lactating (NL) women at a
single center from 2003-2006. In both cases, Staph
aureus was the most commonly
isolated organism (67.7% from LA, 30.5% from NL, and 42.6% of all
cultures overall) The majority of these S. aureus isolates
were
MSSA not MRSA (39 vs. 3.7%). Importantly, the second most commonly
isolated class of bacteria were mixed anaerobes (13.7% overall),
followed by anaerobic cocci (6.3% overall). The authors, therefore
strongly suggested that anaerobic coverage be a component
of all initially empiric coverage for breast abscesses.
A second article [2] similarly tracked the culture results of 46 drained breast abscesses in a community setting. Staphylococcus aureus
was again the most common aerobic organism, present in 12 cultures (32%). In contrast to the previous article, 58% of the S. aureus isolates
were MRSA. The remaining positive cultures yielded Coag-negative Staph (16%), diphtheroids (16%),
and Pseudomonas aeruginosa (8%).
This
study was severely limited for estimating the prevalence of infection
with anaerobic bacteria, as only 8/46 abscesses had swabs sent for
anaerobic culture. Of these 2/8 (25%) grew anaerobes.
Take-home:
- In addition to arranging for I&D, cover for at least Staph aureus (MRSA if you suspect it) and Anaerobes when treating breast abscesses.
- If the person is sick and septic like our clinical scenario, cover broadly for MRSA, anaerobes and pseudomonas as well. Possible options include:
- In addition to arranging for I&D, cover for at least Staph aureus (MRSA if you suspect it) and Anaerobes when treating breast abscesses.
- If the person is sick and septic like our clinical scenario, cover broadly for MRSA, anaerobes and pseudomonas as well. Possible options include:
Inpatient - Vancomycin & Zosyn OR Vancomycin & Unasyn.
Outpatient - Augmentin (if nursing) OR Bactrim/Flagyl if MRSA suspected.
References:
[1]
Dabbas, N., Chand, M., Pallett, A., Royle, G. T., & Sainsbury,
R. (2010). Have the Organisms that Cause Breast Abscess Changed With
Time?––Implications for Appropriate Antibiotic
Usage in Primary and Secondary Care. The breast journal, 16(4), 412-415.
[2] Moazzez,
A., Kelso, R. L., Towfigh, S., Sohn, H., Berne, T. V., & Mason,
R. J. (2007). Breast abscess bacteriologic features in the era of
community-acquired methicillin-resistant Staphylococcus
aureus epidemics. Archives of Surgery, 142(9), 881-884.
Contributed by Maia Dorsett, PGY-3
Faculty Reviewed by Stephen Liang