What are the causes of vaginal burning?

Common Causes of Vaginal Burning

Vaginal burning is most commonly caused by infectious conditions such as vulvovaginal candidiasis, bacterial vaginosis, and trichomoniasis, with noninfectious causes like atrophic, irritant, allergic, and inflammatory vaginitis accounting for a smaller percentage of cases. 1, 2

Infectious Causes

1. Vulvovaginal Candidiasis (VVC)

• Key symptoms: Intense itching, vulvar burning, vaginal soreness, dyspareunia, external dysuria 3, 1
• Physical findings: White, thick, "cottage cheese-like" discharge, erythema in vulvovaginal area 1
• Diagnostic characteristics:
  • pH ≤4.5 (normal)
  • Minimal or no odor
  • Presence of yeast or pseudohyphae on microscopy with 10% KOH preparation 1

2. Bacterial Vaginosis (BV)

• Key symptoms: Vaginal discharge and fishy odor (often worse after intercourse) 1
• Physical findings: Homogeneous, white, thin discharge 1
• Diagnostic characteristics:
  • pH >4.5
  • Positive whiff test (fishy odor with 10% KOH)
  • Clue cells on microscopy 3, 4

3. Trichomoniasis

• Key symptoms: Diffuse vaginal burning/irritation, sometimes minimal symptoms 3
• Physical findings: Malodorous, yellow-green discharge 3
• Diagnostic characteristics:
  • pH >5.4
  • Trichomonads visible on saline wet mount
  • More leukocytes than epithelial cells 4

Noninfectious Causes

1. Atrophic Vaginitis

• Key symptoms: Vaginal dryness, itching, irritation, burning, dyspareunia 4
• Physical findings: Thin, pale vaginal mucosa with decreased rugae
• Associated factors: Estrogen deficiency (menopause, postpartum, breastfeeding) 2, 4

2. Contact Dermatitis (Irritant or Allergic)

• Key symptoms: Burning, itching, irritation 4
• Physical findings: Erythema, sometimes with edema
• Associated factors: Soaps, douches, spermicides, latex condoms, feminine hygiene products 2

3. Inflammatory Vaginitis

• Key symptoms: Burning, discharge, dyspareunia
• Physical findings: Purulent discharge, erythema
• Diagnostic characteristics: Increased parabasal cells, increased neutrophils 5

Diagnostic Approach

When evaluating vaginal burning, consider these key diagnostic tests:

• Vaginal pH measurement (>4.5 suggests BV or trichomoniasis; ≤4.5 suggests candidiasis) 1
• Microscopy with saline wet mount and 10% KOH preparation 1
• Whiff test (fishy odor with 10% KOH application suggests BV) 4
• Nucleic acid amplification testing for trichomoniasis in symptomatic women 2

Treatment Considerations

For Vulvovaginal Candidiasis:

• Topical azoles (clotrimazole, miconazole, tioconazole, terconazole) for 1-14 days OR
• Oral fluconazole 150mg single dose 1
• Note: Only topical azoles should be used during pregnancy 1

For Bacterial Vaginosis:

• Metronidazole 500mg orally twice daily for 7 days OR
• Metronidazole gel 0.75% intravaginally once daily for 5 days OR
• Clindamycin cream 2% intravaginally at bedtime for 7 days 1

For Trichomoniasis:

• Metronidazole orally (recommended regimen) 3
• Treatment of sex partners is essential to prevent reinfection 3

For Atrophic Vaginitis:

• Topical or systemic estrogen therapy 4

Important Clinical Pearls

• Recurrent vulvovaginal candidiasis (≥4 episodes per year) requires longer initial therapy followed by maintenance antifungal regimen for 6 months 3
• Women with HIV should receive the same treatment regimens as those without HIV for VVC, BV, and trichomoniasis 3
• Patients should avoid sexual intercourse until treatment is complete and symptoms resolve, particularly with trichomoniasis 3
• Clindamycin cream and ovules are oil-based and may weaken latex condoms and diaphragms 1
• Metronidazole may cause disulfiram-like reactions with alcohol consumption 1
• Follow-up is generally unnecessary if symptoms resolve after treatment 1