Antibiotic Treatment for Bacterial Vulvitis
For bacterial vulvitis, treat with oral metronidazole 500 mg twice daily for 7 days, which achieves a 95% cure rate and is the CDC-recommended first-line therapy. 1
Primary Treatment Approach
The distinction between vulvitis and vaginitis is important, but when bacterial infection is confirmed, the treatment algorithm follows established guidelines:
- Metronidazole 500 mg orally twice daily for 7 days is superior to single-dose regimens, with cure rates of 95% versus 84% for the 2g single dose 1, 2
- Patients must avoid alcohol during treatment and for 24 hours afterward due to disulfiram-like reactions 1, 2
- The 7-day regimen provides better symptom relief and improvement in bacterial flora disturbances 1
Alternative Regimens
If oral metronidazole is not tolerated or contraindicated:
- Clindamycin 300 mg orally twice daily for 7 days is an effective alternative 1
- Clindamycin is FDA-indicated for serious infections by susceptible anaerobes, streptococci, pneumococci, and staphylococci, though it carries a risk of colitis 3
- Topical clindamycin cream 2% (5g intravaginally at bedtime for 7 days) can be used, though this is more appropriate for vaginitis than vulvitis 1
Special Clinical Situations
Pregnancy
- Clindamycin vaginal cream is preferred in the first trimester because metronidazole is contraindicated 1
- After the first trimester, oral metronidazole can be used, though topical preparations may still be preferable to limit fetal exposure 1
Allergy or Intolerance
- Clindamycin is the preferred alternative for patients with metronidazole allergy 1
- Patients allergic to oral metronidazole should not receive metronidazole vaginally 1
Common Pitfalls to Avoid
- Do not treat asymptomatic patients unless they have risk factors such as planned invasive procedures (surgical abortion, hysterectomy, IUD placement) 1
- Partner treatment is not routinely recommended as it does not influence cure rates or recurrence in clinical trials 1
- Avoid incomplete treatment courses, as recurrence rates can reach 80% at nine months even with appropriate therapy 4
- Follow-up is unnecessary if symptoms resolve, but recurrence is common and may require retreatment with alternative regimens 1
Important Diagnostic Considerations
Before initiating antibiotics, confirm bacterial etiology rather than other causes:
- Bacterial vaginosis/vulvitis is diagnosed by Amsel criteria (pH >4.5, positive whiff test, clue cells) or Gram stain 5, 6
- Rule out vulvovaginal candidiasis (requires antifungals, not antibiotics) and trichomoniasis (requires different metronidazole dosing) 1, 5
- Non-infectious causes (atrophic, irritant, allergic vulvitis) account for 5-10% of cases and do not respond to antibiotics 7