How should I evaluate and manage a woman with vaginal discharge to diagnose and treat bacterial vaginosis, vulvovaginal candidiasis, trichomoniasis, and atrophic vaginitis?

Diagnosis and Treatment of Vaginitis

Immediate Diagnostic Approach

Order a wet prep with pH testing at the point of care, combined with NAAT testing for Chlamydia trachomatis, Neisseria gonorrhoeae, and Trichomonas vaginalis to ensure comprehensive diagnosis. 1

Critical Timing for Wet Prep

• Examine the wet prep within 30 minutes to 2 hours of collection, as motile trichomonads lose viability and become undetectable after this window 2, 1
• Collect vaginal swabs from pooled vaginal discharge or lateral vaginal walls, avoiding cervical mucus contamination 2

Three-Component Wet Prep Examination

Saline Wet Mount:

• Look for clue cells (bacterial-covered epithelial cells indicating bacterial vaginosis) 3, 1
• Identify motile flagellated trichomonads (though sensitivity is only 40-80%, hence the need for NAAT) 2
• Count white blood cells (elevated in trichomoniasis and inflammatory conditions) 1

10% KOH Preparation:

• Visualize pseudohyphae and budding yeast for candidiasis diagnosis 1, 4
• Perform the "whiff test" - a fishy amine odor indicates bacterial vaginosis 3, 1

Vaginal pH Testing:

• pH <4.5 suggests vulvovaginal candidiasis 2, 1
• pH >4.5 indicates bacterial vaginosis or trichomoniasis 3, 2, 1

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Bacterial Vaginosis

Diagnosis

Use the Amsel criteria, requiring 3 of 4 findings: 3, 5, 4

• Homogeneous white discharge that smoothly coats vaginal walls 3
• Vaginal pH >4.5 3
• Positive whiff test (fishy odor with 10% KOH) 3
• Clue cells on microscopy 3

While Gram stain (Nugent criteria) is the gold standard laboratory method, it is not required for routine clinical diagnosis when Amsel criteria can be applied 3, 1

Treatment for Non-Pregnant Women

First-line therapy: Oral metronidazole 500 mg twice daily for 7 days 6, 5, 4

Alternative regimens: 6, 5

• Intravaginal metronidazole gel
• Oral or intravaginal clindamycin cream

For recurrent bacterial vaginosis (multiple documented recurrences):

• Use longer courses of therapy 5

Follow-up:

• Unnecessary if symptoms resolve 6
• Patients should return only if symptoms recur 6

Treatment in Pregnancy

All symptomatic pregnant women must be tested and treated because bacterial vaginosis is associated with premature rupture of membranes, preterm labor, preterm birth, and postpartum endometritis 6

Recommended treatment: 6

• Oral metronidazole or clindamycin

Mandatory follow-up:

• Perform follow-up evaluation one month after treatment completion to verify therapeutic effectiveness due to risk of adverse pregnancy outcomes 6

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Vulvovaginal Candidiasis (VVC)

Classification

Uncomplicated VVC: 6

• Sporadic or infrequent episodes
• Mild to moderate symptoms
• Likely caused by Candida albicans
• Present in nonimmunocompromised women

Complicated VVC: 6

• Recurrent (4 or more episodes per year) 5
• Severe symptoms
• Caused by non-albicans Candida species
• Present in pregnant women or those with uncontrolled diabetes, debilitation, or immunosuppression

Diagnosis

• Clinical presentation: pruritus, erythema in vulvovaginal area, white discharge 6
• Vaginal pH <4.5 (normal) 6, 2
• 10% KOH preparation showing yeasts or pseudohyphae 6, 1
• Culture is mandatory for recurrent infections to identify non-albicans species requiring different treatment 2, 1

Treatment for Uncomplicated VVC

Short-course topical azoles (single dose or 1-3 days) achieve 80-90% cure rates: 6

Intravaginal options include: 6

• Clotrimazole 1% cream 5g for 7-14 days
• Clotrimazole 100mg tablet for 7 days
• Clotrimazole 500mg tablet, single dose
• Miconazole 2% cream 5g for 7 days
• Terconazole 0.4% cream 5g for 7 days
• Terconazole 0.8% cream 5g for 3 days

Oral option:

• Fluconazole 150mg single dose 6

Important caveat: Oil-based creams and suppositories may weaken latex condoms and diaphragms 6

Treatment for Complicated/Recurrent VVC

Initial therapy:

• Longer duration of therapy required to achieve remission 6

Maintenance therapy (after initial remission):

• Weekly oral fluconazole for up to 6 months 5
• Alternative maintenance regimens include clotrimazole, ketoconazole, or itraconazole for 6 months 6

Treatment in Pregnancy

Only 7-day topical azole therapies are recommended for pregnant women 6

• Oral fluconazole is contraindicated in pregnancy 6

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Trichomoniasis

Diagnosis

NAAT testing is essential because wet mount microscopy has only 40-80% sensitivity and requires examination within 30 minutes to 2 hours 2, 1

Recommended diagnostic approach: 2, 1, 4

• NAAT for Trichomonas vaginalis (superior sensitivity)
• Antigen testing using immunoassay
• DNA probe testing

Clinical findings: 6

• Diffuse, malodorous, yellow-green discharge
• Vulvar irritation
• Vaginal pH >4.5 2
• Red punctate lesions on cervix (strawberry cervix) 1

Treatment for Non-Pregnant Women

Recommended regimens (90-95% cure rates): 6, 5

• Oral metronidazole 2g single dose
• OR oral metronidazole 500mg twice daily for 7 days

Both regimens are equally effective 5

Partner treatment:

• Treat all sex partners, even without screening, to enhance cure rates 6, 5
• Patients should avoid sex until both partners are cured 6

For treatment-resistant cases:

• Higher-dose therapy may be needed 5

Follow-up:

• Test of cure is not recommended for initially asymptomatic patients who become asymptomatic after treatment 6, 5

Treatment in Pregnancy

Symptomatic pregnant women should be treated to relieve symptoms and prevent preterm birth, premature rupture of membranes, and low birthweight 6

Recommended treatment:

• Oral metronidazole 2g single dose 6

Safety note:

• Multiple studies and meta-analyses have not demonstrated consistent association between metronidazole use during pregnancy and teratogenic or mutagenic effects 6

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Atrophic Vaginitis

Diagnosis

• Results from estrogen deficiency 7
• Presents with vaginal dryness, irritation, dyspareunia 4
• Vaginal pH typically elevated 4

Treatment

• Topical estrogen therapy is effective 7
• Nonhormonal therapies are alternative options 4

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Critical Pitfalls to Avoid

Never rely solely on wet mount for Trichomonas - sensitivity is only 40-80% and requires living organisms examined within 30 minutes to 2 hours 2

Don't assume normal pH excludes all infections - yeast typically has pH <4.5, while bacterial vaginosis and trichomoniasis have pH >4.5 2

Don't delay wet mount examination beyond 2 hours if using this method, as organisms lose motility and become undetectable 2, 1

Culture is not recommended for bacterial vaginosis diagnosis because G. vaginalis can be isolated from half of normal women, lacking specificity 3

Always order NAAT testing simultaneously with wet prep - microscopy alone has significant limitations for detecting all three major causes of infectious vaginitis 2, 1