What are the possible causes and treatments for a woman experiencing burning pain in the vagina?

Burning Pain in the Vagina: Causes and Treatment

Most Common Infectious Causes

The three most common infectious causes of vaginal burning are vulvovaginal candidiasis (20-25% of cases), bacterial vaginosis (40-50% of cases), and trichomoniasis (15-20% of cases), and these should be ruled out first before considering other etiologies. 1

Vulvovaginal Candidiasis (VVC)

• Characterized by pruritus, vulvovaginal erythema, white discharge resembling cottage cheese, normal vaginal pH (<4.5), and visualization of yeasts or pseudohyphae on wet mount or KOH preparation 2
• Approximately 75% of women will experience at least one episode during their lifetime 3
• Diagnosis requires both clinical signs/symptoms AND microscopic confirmation with KOH prep showing yeasts/pseudohyphae 2

Treatment for uncomplicated VVC:

• First-line: Fluconazole 150 mg oral single dose OR short-course topical azole therapy (1-3 days), achieving 80-90% cure rates 2, 4
• Alternative topical options: Clotrimazole 1% cream 5g intravaginally for 7-14 days, miconazole 2% cream 5g intravaginally for 7 days, or terconazole 0.8% cream 5g intravaginally for 3 days 2
• Pregnant women must receive ONLY topical azoles for 7 days—oral fluconazole is contraindicated in pregnancy 2, 4

Bacterial Vaginosis (BV)

• Characterized by vaginal discharge with fishy odor, elevated pH (>4.5), and clue cells on microscopy 2
• Treated with oral metronidazole, intravaginal metronidazole, or intravaginal clindamycin 1
• Cure rates of 90-95% with appropriate treatment 3

Trichomoniasis

• Presents with diffuse malodorous yellow-green discharge, vulvar irritation, and burning 2
• Treated with oral metronidazole achieving 90-95% cure rates 2
• Sex partners MUST be treated concurrently, and patients should avoid intercourse until both partners complete therapy 3

Recurrent Infections Require Different Management

For recurrent VVC (≥4 episodes per year), longer initial therapy (7-14 days topical OR fluconazole 150 mg repeated after 3 days) followed by maintenance antifungal regimen for 6 months is required 5, 2

• Maintenance options include clotrimazole, fluconazole, or other azoles continued for 6 months 5
• Obtain cultures to identify non-albicans Candida species (present in 10-20% of recurrent cases), particularly C. glabrata, which may require different treatment 5
• Evaluate for predisposing conditions: diabetes, immunosuppression, HIV infection, and recent antibiotic use 5, 2

Non-Infectious Causes (5-10% of Cases)

When infectious causes are excluded, consider:

Atrophic Vaginitis

• Common in postmenopausal women due to estrogen deficiency 1
• Treated with hormonal and nonhormonal therapies 1

Vulvodynia

• Chronic vulvar pain without identifiable cause, affecting up to 16% of women, described as burning, stinging, irritation, or rawness 6
• This is a diagnosis of exclusion after ruling out infections and dermatologic conditions 6, 7
• May be generalized or localized (vestibulodynia, clitorodynia) 6
• Requires individualized, often multidisciplinary approach including vulvar care measures, psychological approaches, local treatment, oral medications, or physical therapy 6

Contact Dermatitis and Inflammatory Conditions

• Irritant or allergic reactions to soaps, detergents, feminine hygiene products 1
• Inflammatory vaginitis may improve with topical clindamycin and steroid application 1

Diagnostic Algorithm

1. Obtain vaginal pH: Normal (<4.5) suggests VVC; elevated (>4.5) suggests BV or trichomoniasis 2
2. Perform wet mount microscopy: Look for yeasts/pseudohyphae (VVC), clue cells (BV), or motile trichomonads 2, 1
3. KOH preparation: Enhances visualization of fungal elements and produces "whiff test" for BV 3
4. If microscopy negative but symptoms persist: Consider nucleic acid amplification testing for trichomoniasis or DNA probe testing for VVC 1
5. For recurrent infections: Obtain cultures to identify specific pathogens and non-albicans species 5

Critical Pitfalls to Avoid

• Do NOT continue empiric antifungal therapy without confirmed fungal infection—this delays appropriate treatment 8
• Do NOT assume all vaginal burning is candidiasis—only 20-25% of vaginitis cases are fungal 1
• Do NOT prescribe oral fluconazole to pregnant women—use only topical azoles 2, 4
• Do NOT neglect partner treatment for trichomoniasis—reinfection rates are high without concurrent partner therapy 3
• Do NOT overlook predisposing conditions in recurrent cases—diabetes, immunosuppression, and antibiotic use significantly increase recurrence risk 5, 2

When Symptoms Persist After Treatment

• If symptoms persist or recur within 2 months, patients should return for reevaluation 3
• Consider alternative diagnoses including vulvodynia, atrophic vaginitis, or dermatologic conditions 1, 6
• For culture-documented infections that fail standard therapy with reinfection excluded, consult an expert and consider susceptibility testing 3