What are the diagnosis and treatment options for vaginosis or yeast infection?

Diagnosis and Treatment for Vaginosis or Yeast Infection

The diagnosis of vaginosis and yeast infections requires microscopic examination of vaginal discharge with pH testing, while treatment involves metronidazole for bacterial vaginosis and fluconazole or topical azoles for yeast infections. 1

Diagnostic Approach

Bacterial Vaginosis (BV)

BV is diagnosed when 3 of the following 4 clinical criteria (Amsel criteria) are present:

• Homogeneous, white discharge that adheres to vaginal walls
• Presence of clue cells on microscopic examination
• Vaginal pH > 4.5
• Positive "whiff test" (fishy odor when 10% KOH is added to discharge) 1

Alternative diagnostic method:

• Gram stain of vaginal discharge (considered the diagnostic standard) 1, 2
• Newer laboratory tests that detect Gardnerella vaginalis DNA or vaginal fluid sialidase activity 2

Vulvovaginal Candidiasis (Yeast Infection)

Diagnosis is made by:

• Clinical signs and symptoms (itching, irritation, white discharge)
• Microscopic examination of vaginal discharge with 10% KOH showing yeast or pseudohyphae 1
• Normal vaginal pH (< 4.5) 1, 3
• Culture may be helpful for recurrent cases or when microscopy is negative 1

Trichomoniasis

Diagnosed by:

• Microscopic examination showing motile trichomonads in saline wet mount
• pH > 4.5
• Nucleic acid amplification testing (NAAT) is recommended by CDC for symptomatic or high-risk women 1, 2
• Culture is more sensitive than microscopy but less commonly used 1

Treatment Recommendations

Bacterial Vaginosis

Recommended regimen:

• Metronidazole 500 mg orally twice daily for 7 days 1, 4

Alternative regimens:

• Intravaginal metronidazole gel
• Intravaginal clindamycin cream 2, 4

For recurrent BV:

• Extended course of metronidazole (500 mg twice daily for 10-14 days)
• If ineffective, metronidazole vaginal gel 0.75% for 10 days, followed by twice weekly for 3-6 months 5
• Tinidazole has shown efficacy in clinical trials (2g once daily for 2 days or 1g once daily for 5 days) 6

Vulvovaginal Candidiasis

Recommended regimen:

• Fluconazole 150 mg oral single dose 7, 2
• Topical azole medications (equally effective to oral treatment) 2, 4

For recurrent vulvovaginal candidiasis (≥4 episodes/year):

• Initial therapy followed by maintenance with weekly oral fluconazole for up to 6 months 4
• Longer courses of topical azoles may be required for resolution 4

Note: Only topical azoles are recommended during pregnancy 2

Trichomoniasis

Recommended regimen:

• Metronidazole 2g orally in a single dose OR
• Metronidazole 500 mg twice daily for 7 days (both regimens have equal cure rates up to 88%) 4
• Tinidazole is an alternative option 6
• Treatment of sex partners is essential for cure 4

Important Clinical Considerations

1. Sample collection and transport:

   • For microscopic examination, samples should be examined within 2 hours of collection 1
   • For DNA testing, samples can be transported at room temperature for up to 7 days 1

2. Mixed infections:

   • Infections may be mixed and present with atypical manifestations 1
   • Comprehensive testing for all three common causes is recommended when symptoms are present

3. Treatment pitfalls:

   • BV: Treatment of male partners has not been shown to prevent recurrence 1
   • Trichomoniasis: Partner treatment is essential even without screening 4
   • Candidiasis: Recurrent cases may require extended therapy 4

4. Special situations:

   • Consider treatment of asymptomatic BV before invasive gynecologic procedures to reduce risk of post-procedure infections 1
   • Symptomatic trichomoniasis should be treated during pregnancy to prevent preterm birth 4

5. Diagnostic challenges:

   • Point-of-care tests vary widely in sensitivity and specificity 1
   • Laboratory testing fails to identify a cause in a substantial minority of women 1
   • Wet mount examination for trichomonads has low sensitivity (40-70%) compared to NAAT 1

By following this algorithmic approach to diagnosis and treatment, providers can effectively manage these common vaginal conditions and improve patient outcomes.