Methicillin-resistant Staphylococcus aureus as a common cause of vulvar abscesses

To estimate the incidence of methicillin-resistant Staphylococcus aureus (MRSA) among women with vulvar abscesses and to describe clinical factors associated with inpatient compared with outpatient treatment.

We reviewed all women with a vulvar abscess who were treated with incision and drainage between October 2006 to March 2008. We reviewed the abscess cultures and evaluated clinical and laboratory variables associated with inpatient compared with outpatient treatment.

During the 80-week study period, 162 women were treated for a vulvar abscess. Methicillin-resistant S aureus was isolated from 85 of 133 (64%) cultured vulvar abscesses. No presenting signs or symptoms were more common among patients with MRSA abscesses. Women with an MRSA vulvar abscess were not more likely to require inpatient admission or experience treatment complications. Inpatient treatment occurred in 64 of 162 (40%) patients and was predicted by medical comorbidities: diabetes (45.3%, odds ratio [OR] 2.29, 95% confidence interval [CI] 1.12-4.72), hypertension (34.4%, OR 2.33, 95% CI 1.06-5.13), initial serum glucose greater than 200 (37.5%, OR 3.32, 95% CI 1.48-7.51), and signs of worse infection, ie, larger abscesses (mean 5.2 cm) (P<.001) and elevated white blood cell count of at least 12,000/mm3 (45.3%, OR 3.04, 95% CI 1.44-6.43).

Methicillin-resistant S aureus was the most common organism isolated from vulvar abscesses. Inpatient treatment is more common in women with medical comorbidities, larger abscesses, and signs of systemic illness. An antibiotic regimen with activity against MRSA, such as trimethoprim-sulfamethoxazole, should be considered in similar populations with vulvar abscesses.