Bacterial vaginosis

Background

• Accounts for up to 50% of cases of vaginitis
• Associated with preterm labor and premature rupture of membranes

Clinical Features

• whitish-gray discharge and odor
  • Lack of discharge makes diagnosis less likely
• May have history of "physiologic whiff test" after contact with male ejaculate which is alkaline (like KOH)

Differential Diagnosis

Vulvovaginitis

• Bacterial vaginosis
• Candida vaginitis
• Trichomonas vaginalis
• Contact vulvovaginitis
• Atrophic vaginitis
• Lichen sclerosus
• Tinea cruris
• Chlamydia/Gonorrhea infection

Evaluation

Work-up

• Wet mount shows clue cells: bacteria that line the borders of the vaginal epithelial cells
• Whiff Test: fishy odor with 10% KOH prep
• CDC recommends testing all women with BV for HIV and other STDs

Amsel criteria for diagnosis (3/4 must be present)

• Homogeneous, thin, gray-white discharge
• Positive whiff test
• Vaginal pH>4.5
• Clue cells on wet mount (at least 20% of epithelial cells)

Management

• No need to treat if asymptomatic (even if pregnant)
• Do NOT need to treat sexual partner

Antibiotics

First Line Therapy

• Metronidazole 500 mg PO BID for 7 days OR
• Metronidazole gel 0.75%, one full applicator (5 g) intravaginally, qd for 5 days OR
• Clindamycin cream 2%, one full applicator (5 g) intravaginally qHS for 7 days

Alternative Regimin

• Tinidazole 2 g PO qd for 2 days OR
• Tinidazole 1 g PO qd for 5 days OR
• Clindamycin 300 mg PO BID for 7 days OR
• Clindamycin ovules 100 mg intravaginally qHS for 3 days (do not use if patient has used latex condom in last 72 hrs)

Pregnant

• Metronidazole 250mg PO q8h x 7 days
• Metronidazole 2g PO x 1 dose is also acceptable
• Multiple studies have not demonstrated teratogenicity from metronidazole use

Prophylaxis (Sexual Assault)

• Metronidazole 2 g PO x 1 OR
• Tinidazole 2 g PO x 1

Disposition

• Discharge

See Also

• Vulvovaginitis

References

Authors

Ross Donaldson