Bacterial vaginosis

Background

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

Evaluation

Work-up

A "clue cell": note effacement of borders by bacteria, as compared to normal epithelial cells below.
Normal vaginal epithelial cells on wet mount: note clean borders. Presence of lactobacilli (tiny rods) is normal.
  • Wet mount shows clue cells: vaginal epithelial cells with "stippled appearance" due to coverage by bacteria
  • Whiff Test: fishy odor with 10% KOH prep
  • CDC recommends testing all women with BV for HIV and other STDs [1]

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
    • In pregnant patients, consider treating to prevent preterm birth, though evidence is conflicting[2]
  • Do NOT need to treat sexual partner

Antibiotics

First Line Therapy[3]

  • 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

Prophylaxis (Sexual Assault)

Disposition

  • Discharge

See Also

References

  1. 1.0 1.1 1.2 1.3 CDC Pregnancy BV Treatment Guidelines.cdc.gov
  2. Cochrane Database of Systemic REviews. January 2013. Antibiotics for treating bacterial vaginosis in pregnancy. https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0010584/
  3. Workoski KA and Bolan GA. Sexually transmitted diseases treatment guidelines, 2015. MMWR Recommen and Reports. 2015; 64(3):1-140.