What if all bacterial vaginosis (BV) tests and candida tests are negative for the vaginal swab and all sexually transmitted diseases (STDs) are negative, but the patient reports a persistent vaginal odor?

Management of Persistent Vaginal Odor with Negative Test Results

When all bacterial vaginosis tests, candida tests, and STD tests are negative but the patient reports persistent vaginal odor, further evaluation for non-infectious causes is recommended, including assessment of hygiene practices, consideration of cytolytic vaginosis, and evaluation for genitourinary syndrome of menopause in appropriate age groups. 1

Diagnostic Considerations for Persistent Odor

When standard testing is negative, consider these potential causes:

• Non-infectious causes:

  • Personal hygiene practices
  • Retained foreign body (tampon, condom)
  • Cytolytic vaginosis (overgrowth of lactobacilli)
  • Desquamative inflammatory vaginitis
  • Genitourinary syndrome of menopause (in perimenopausal/menopausal women)

• Testing limitations:

  • The CDC guidelines note that despite diagnostic testing, 25%-40% of genital symptoms may not have a specific identified cause 2
  • Standard tests may miss some cases of bacterial vaginosis when using culture alone rather than Gram stain or microbiome-based assays 2

Evaluation Algorithm

1. Re-evaluate diagnosis:

   • Confirm proper specimen collection and testing methods were used
   • Consider pH testing (pH >4.5 suggests BV or trichomoniasis) 1
   • Review Amsel's criteria for BV (requires 3 of 4: homogeneous discharge, clue cells, pH >4.5, positive whiff test) 1

2. Consider less common infections:

   • Test for Mycoplasma genitalium, which is recognized as an emerging cause of genital symptoms 2
   • Consider testing for Trichomonas if not already done (NAAT preferred) 2

3. Assess hygiene practices:

   • Douching (significantly associated with BV with PR 1.17 for weekly use) 3
   • Type of underwear (nylon vs. cotton)
   • Bathing frequency
   • Use of hygiene sprays, powders, or towelettes

Management Recommendations

1. Modify hygiene practices:

   • Discontinue douching, as it is consistently associated with BV 3
   • Avoid use of perfumed products in the genital area
   • Wear cotton underwear
   • Avoid tight-fitting clothing

2. Empiric treatment considerations:

   • If clinical suspicion for BV remains high despite negative tests:
     • Metronidazole 500mg orally twice daily for 7 days (95% cure rate) 1
     • Alternative: Metronidazole gel 0.75% intravaginally once daily for 5 days 1

3. For recurrent symptoms:

   • Consider boric acid vaginal suppositories (600mg daily for 14 days) 4
   • For postmenopausal women, consider vaginal estrogen with or without lactobacillus-containing probiotics 1

Follow-up Recommendations

• Schedule follow-up in 2-4 weeks to reassess symptoms
• If symptoms persist despite interventions, consider referral to gynecology for specialized evaluation
• Consider testing sexual partners if symptoms persist, as reinfection from asymptomatic partners is common 2

Important Caveats

• Symptoms alone have limited diagnostic power - absence of perceived odor makes bacterial vaginosis unlikely (LR 0.07) 5
• The presence of a "high cheese" odor on examination is predictive of bacterial vaginosis (LR 3.2) 5
• Gardnerella vaginalis is still considered a prime suspect in BV pathogenesis, but BV is polymicrobial in nature 6
• Partner notification and treatment may be necessary to prevent reinfection, particularly if symptoms persist 1