By Will Boggs, MD

NEW YORK (Reuters Health) - Abscesses of the vulva, the area around the opening of the vagina, often contain methicillin-resistant Staphylococcus aureus (MRSA), according to a report in the journal Obstetrics & Gynecology.

As the name implies, MRSA is a microbe that is resistant to the antibiotic methicillin. Unfortunately, it is also usually resistant to a host of other antibiotics, making it difficult to treat. To prevent the spread of this organism, hospitalized patients with MRSA are usually placed in isolation until the infection has cleared.

An abscess is a large collection of pus. To effectively treat the problem, the abscess usually needs to be cut open and drained.

"We want ob-gyns to realize that vulvar abscesses, like other skin and soft tissue infections, have a high incidence of MRSA," Dr. Andrea Ries Thurman from the University of Texas Health Sciences Center, San Antonio, told Reuters Health. "You cannot predict MRSA (versus other bacteria) by looking at the patient."

Thurman and colleagues sought to determine the rate of MRSA in a large group of women with vulvar abscesses who were treated with either inpatient or outpatient surgical drainage, and to identify clinical factors associated with MRSA vulvar abscesses.

MRSA was found in 64 percent of vulvar abscesses, the investigators report, and other non-MRSA organisms were isolated from 36 percent of vulvar abscesses.

Most MRSA isolates were sensitive to clindamycin, trimethoprim-sulfamethoxazole, or doxycycline.

No presenting signs, symptoms, or patient factors significantly predicted MRSA vulvar abscesses, the report indicates, and MRSA infection was not associated with inpatient treatment or the occurrence of any short-term complication.

"Our study demonstrates that vulvar abscesses are a morbid condition, with 40 percent of women requiring inpatient treatment for an average of 3 days," the investigators say.

"Our data suggest that if an oral antibiotic is prescribed, trimethoprim-sulfamethoxazole should be the first line of treatment, because this medication covered almost all of the MRSA and non-MRSA (microbes) recovered from vulvar abscesses," the authors conclude.

SOURCE: Obstetrics and Gynecology, September 2008.

Related MedlinePlus Pages:

• MRSA
• Vulvar Disorders