Bacterial Vaginosis

Female pt with h/o smoking, vaginal douching, presents with thin, malodorous discharge that is worse after intercourse. Reports unprotected sexual encounters with multiple sexual partners, including women. Speculum exam reveals thin, homogeneous discharge with fishy odor. Vaginal pH >4.5, positive whiff test and multiple clue cells present on microscopy.

Clue cells indicated by yellow boxes

Clue cells indicated by yellow boxes

  • Start oral metronidazole 500 mg PO BID x 7 days

  • Pt advised to return for treatment if symptoms recur

Notes

  • Epidemiology

    • 50% of vaginitis cases

    • Often caused by Gardnerella vaginalis

    • Higher risk among women who have sex with women

    • Infected patients are at increased risk for HIV, gonorrhea/chlamydia

  • Diagnosis based on Amsel criteria

    • Criteria include

      • Thin, homogeneous discharge

      • Vaginal pH >4.5

      • Positive whiff test with 10% KOH solution

      • Clue cells on microscopy

    • 3 of 4 criteria required for diagnosis

  • Pregnancy

    • Treatment during pregnancy improves symptoms, but does not prevent preterm birth

    • Vaginal metronidazole can be used in non-pregnant women, but oral metronidazole must be used in pregnancy