What is the best course of treatment for a malodorous vaginal smell with no abnormal discharge, burning, or itching, that has shown partial relief with boric acid capsules and over-the-counter (OTC) Canesten (clotrimazole)?

Treatment for Malodorous Vaginal Smell Without Other Symptoms

For malodorous vaginal smell without abnormal discharge, burning, or itching that has shown partial response to boric acid and clotrimazole, bacterial vaginosis is the most likely diagnosis and should be treated with oral metronidazole 500 mg twice daily for 7 days or intravaginal metronidazole gel for 5 days.

Differential Diagnosis

When evaluating malodorous vaginal smell with no abnormal discharge, burning, or itching, consider:

1. Bacterial vaginosis (BV) - Most common cause of vaginal malodor

   • Characterized by fishy odor, often with minimal discharge
   • pH typically >4.5
   • Often responds partially to boric acid

2. Non-albicans Candida species - Particularly C. glabrata

   • May present with minimal symptoms besides odor
   • Partial response to clotrimazole (Canesten)
   • Often requires different treatment than typical candidiasis

3. Trichomoniasis - Less likely with absence of discharge

   • Can sometimes present with minimal symptoms besides odor

Diagnostic Approach

Before definitive treatment, the following diagnostic tests are recommended:

• Vaginal pH measurement (BV typically >4.5)
• Microscopic examination with saline and 10% KOH
• Whiff test (fishy odor with KOH)
• Assessment for clue cells

Treatment Algorithm

First-line Treatment (Most Likely Bacterial Vaginosis)

Given the malodorous smell without other symptoms and partial response to boric acid:

1. Oral metronidazole 500 mg twice daily for 7 days 1 OR
2. Metronidazole gel 0.75%, one applicator intravaginally daily for 5 days 1 OR
3. Clindamycin cream 2%, one applicator intravaginally at bedtime for 7 days 1

For Non-albicans Candida (if confirmed)

If microscopy or culture confirms non-albicans Candida species:

1. Boric acid 600 mg in gelatin capsule intravaginally daily for 14 days 1

   • This is particularly effective for C. glabrata infections unresponsive to azoles
   • Continue this treatment since it has already shown partial response

2. Alternative for non-albicans Candida:

   • Nystatin intravaginal suppositories 100,000 units daily for 14 days 1

For Recurrent Issues

If symptoms recur after initial treatment:

1. For recurrent BV: Consider maintenance therapy with metronidazole gel twice weekly for 4-6 months
2. For recurrent candidiasis: Fluconazole 150 mg weekly for 6 months after initial 10-14 days of induction therapy 1

Important Considerations

• Self-diagnosis is unreliable - Incorrect diagnosis can result in overuse of antifungal agents with subsequent risk of contact and irritant dermatitis 1

• Boric acid effectiveness - While boric acid has shown efficacy for non-albicans Candida species and some cases of BV, its effectiveness ends with the suspension of therapy 2

• Avoid douching - Despite being commonly used, douching is not recommended for treatment of vaginal infections due to associated risks without well-documented benefits 3

• Partner treatment - Not typically required for BV or candidiasis, but should be considered if symptoms persist or recur

• Follow-up - Reevaluation is necessary if no improvement is seen after 72 hours of appropriate therapy

Pitfalls to Avoid

1. Assuming all malodor is candidiasis - The most common cause of vaginal malodor is actually bacterial vaginosis

2. Continuing ineffective treatment - If partial response with boric acid and clotrimazole hasn't led to complete resolution, a different approach is needed

3. Missing other diagnoses - While rare with minimal symptoms, trichomoniasis should be considered if standard treatments fail (boric acid has shown some efficacy for resistant cases) 4, 5

4. Neglecting pH testing - This simple test can help distinguish between BV (pH >4.5) and candidiasis (pH typically 4.0-4.5)