What is the appropriate diagnosis and treatment for a woman with vaginal discharge?

Management of Vaginal Discharge in Women

The appropriate approach to vaginal discharge requires measuring vaginal pH and performing microscopy to differentiate between the three most common causes—bacterial vaginosis, vulvovaginal candidiasis, and trichomoniasis—followed by targeted treatment based on the specific diagnosis. 1, 2

Diagnostic Algorithm

Initial Assessment

• Measure vaginal pH using narrow-range pH paper applied directly to vaginal secretions to guide diagnosis: pH >4.5 indicates bacterial vaginosis or trichomoniasis, while pH ≤4.5 suggests vulvovaginal candidiasis 1, 2
• Perform a saline wet mount to identify motile trichomonads (trichomoniasis) or clue cells (bacterial vaginosis) 1, 2
• Perform a KOH preparation to identify yeast or pseudohyphae (candidiasis), which also disrupts cellular material that might obscure the organisms 3, 1
• Conduct a whiff test by applying KOH to vaginal secretions—a positive fishy odor immediately confirms bacterial vaginosis or trichomoniasis 1, 2

Critical pitfall to avoid: Do not treat empirically without proper diagnosis, as 42% of women in community practice receive inappropriate treatment, and those treated empirically without confirmed infection have significantly higher rates of return visits within 90 days 4

Treatment by Specific Diagnosis

Bacterial Vaginosis

• Prescribe metronidazole 500 mg orally twice daily for 7 days as first-line therapy, which achieves a 95% cure rate 1, 5
• Alternative regimen: Clindamycin cream intravaginally 1
• Do not treat male sexual partners—this does not prevent recurrence or alter clinical course 1, 2
• Warn patients to avoid alcohol during treatment and for 24 hours after completion due to disulfiram-like reaction risk 5

Vulvovaginal Candidiasis

• Prescribe fluconazole 150 mg orally as a single dose, which achieves a 55% therapeutic cure rate 1, 6
• Alternative: Use topical azole preparations (butoconazole, clotrimazole, miconazole, or terconazole) for 1-7 days, which achieve 80-90% cure rates 3
• For recurrent vulvovaginal candidiasis (≥4 episodes per year): Initiate a longer course (7-14 days) followed by maintenance therapy with fluconazole 150 mg weekly for 6 months 1, 2
• Do not treat asymptomatic Candida colonization, which is present in 10-20% of women 3, 2
• Partner treatment is not indicated 1

Trichomoniasis

• Prescribe metronidazole 2 grams orally as a single dose, which achieves a 90-95% cure rate 1, 2
• Treat sexual partners simultaneously to prevent reinfection—this is mandatory for trichomoniasis unlike bacterial vaginosis or candidiasis 1, 2
• Instruct patients to avoid sexual contact until both patient and partner complete therapy and are asymptomatic 3

Special Populations

Pregnant Women

• Use only 7-day topical treatments for bacterial vaginosis and candidiasis in pregnancy—avoid oral agents 1, 2
• For trichomoniasis in pregnancy: Metronidazole 2 grams orally as a single dose is safe 3

HIV-Infected Women

• Treat with identical regimens as non-HIV-infected women for all three conditions 3, 1, 2

Follow-Up Recommendations

• Patients should return only if symptoms persist or recur within 2 months—routine test-of-cure is not necessary if symptoms resolve 1, 2
• Recurrence of bacterial vaginosis is common (50-80% within one year) but does not change initial management 2, 5

Critical Pitfalls to Avoid

• Do not recommend self-medication except for women previously diagnosed with candidiasis experiencing identical symptoms 2
• Do not advise vaginal douching, as it disrupts normal flora and increases infection risk 2
• Do not treat partners for bacterial vaginosis or candidiasis—only trichomoniasis requires partner treatment 1, 2
• Avoid empiric treatment without proper diagnostic testing, as this leads to inappropriate antibiotic/antifungal use and higher recurrence rates 4