Bacterial vaginosis
Bacterial vaginosis is a polymicrobial dysbiosis of the vagina caused by loss of lactobacilli and anaerobic overgrowth, diagnosed clinically by the Amsel criteria and treated with oral or intravaginal metronidazole or clindamycin.
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What this article covers
- Overview
Polymicrobial vaginal dysbiosis, not a single infection: bacterial vaginosis (BV) is a shift in the vaginal flora from a lactobacillus-dominant ecosystem to one overgrown with anaerobes, most…
- Epidemiology
The single most common cause of vaginitis, ahead of vulvovaginal candidiasis and trichomoniasis.
- Risk factors
New or multiple sexual partners, the strongest and most consistently identified risk factor.
- Pathophysiology
Loss of hydrogen-peroxide-producing lactobacilli removes the dominant organism that normally keeps vaginal pH low and suppresses anaerobic growth.
- Clinical features
Malodorous, thin, homogeneous white-to-gray vaginal discharge that coats the vaginal walls is the hallmark finding; this discharge, together with the Amsel criteria below, defines the recognizable clinical pattern.
- Differential diagnosis
Trichomoniasis (most important to exclude because it is sexually transmitted and partners require treatment): increased yellow-green, frothy discharge, pruritus and dysuria, "strawberry" cervix with…
- Diagnosis
BV is a clinical diagnosis established by the Amsel criteria: presence of at least three of the following four findings confirms the diagnosis: (1) thin, homogeneous white or gray vaginal discharge…
- Management
Treat every symptomatic patient, regardless of pregnancy status; asymptomatic BV in a nonpregnant patient does not require treatment.
- Complications
Increased acquisition of sexually transmitted infections, including HIV, from the disrupted vaginal epithelial barrier.
- Prognosis
Symptomatic BV responds well to a completed course of first-line therapy, with resolution of discharge and odor in most patients.
- Prevention
Avoid vaginal douching, the single most modifiable behavioral risk factor, since douching disrupts the protective lactobacillus-dominant flora.
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Candida vulvovaginitis presents with vulvar itching, burning, and thick curdy white discharge at a normal vaginal pH; uncomplicated disease clears with a single 150 mg oral fluconazole dose or a short topical azole course, while complicated or recurrent disease needs a longer induction course followed by suppressive therapy.
- Evaluation of vaginal discharge
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