What are the causes of vulvar burning in a 46-year-old woman?

Vulvar Burning in a 46-Year-Old Woman: Causes

Vulvar burning in a 46-year-old woman is most commonly caused by vulvovaginal candidiasis, followed by contact dermatitis, lichen simplex chronicus, and less frequently by inflammatory dermatoses like lichen sclerosus or lichen planus.

Primary Infectious Causes

Vulvovaginal Candidiasis (Most Common)

Vulvovaginal candidiasis is the leading cause of vulvar burning, affecting approximately 75% of women at least once in their lifetime 1, 2. In this age group, VVC presents with vulvar burning, pruritus, vaginal soreness, dyspareunia, and external dysuria 2. The diagnosis requires:

• Clinical signs: vulvar erythema with or without white discharge
• Vaginal pH ≤4.5 (normal)
• Microscopy showing yeasts or pseudohyphae on wet prep or Gram stain
• Culture confirmation when microscopy is negative

Important caveat: 10-20% of asymptomatic women harbor Candida species, so identifying yeast without symptoms does not warrant treatment 1, 2.

Trichomoniasis

While less common as a sole cause of burning, trichomoniasis can present with vulvar burning, external dysuria, and vaginal soreness 1, 2. This should be considered especially if there's associated vaginal discharge and pH >4.5.

Non-Infectious Inflammatory Causes

Contact Dermatitis

Contact dermatitis from irritants or allergens (soaps, detergents, hygiene products, tight clothing) causes vulvar burning, swelling, and irritation 3. This is particularly common in perimenopausal women due to declining estrogen affecting skin barrier function.

Lichen Simplex Chronicus

LSC results from chronic itch-scratch cycles causing skin thickening (lichenification) and burning sensations 4, 3. It's the second most common cause in geriatric populations (42.5% in one study) 4 and can develop at any age.

Lichen Sclerosus

LS causes vulvar burning, pruritus, dyspareunia, and progressive scarring 5, 6. This is critical to diagnose early as it carries a 4-5% risk of squamous cell carcinoma 5. Biopsy is essential for confirmation.

Lichen Planus

LP presents with vulvar burning, erosions, and can cause severe dyspareunia 6, 7. It requires biopsy for diagnosis and aggressive treatment to prevent scarring.

Age-Specific Considerations at 46 Years

At 46, this patient may be perimenopausal, which introduces additional factors:

• Declining estrogen causes vulvovaginal atrophy, thinning of vulvar skin, loss of elasticity and moisture, and altered vaginal pH 8, 4
• Altered vaginal flora from pH changes increases susceptibility to infections 4
• Compromised skin barrier function increases vulnerability to irritants 9

Diagnostic Algorithm

1. Obtain vaginal pH:

   • pH ≤4.5 suggests VVC
   • pH >4.5 suggests trichomoniasis or bacterial vaginosis

2. Perform wet mount microscopy with KOH prep:

   • Yeasts/pseudohyphae = VVC
   • Motile trichomonads = trichomoniasis
   • Clue cells = bacterial vaginosis

3. If microscopy negative but symptoms persist:

   • Culture for Candida and trichomonas
   • Examine for dermatological changes (lichenification, erosions, white plaques, scarring)

4. If no infection identified or symptoms persist after treatment:

   • Biopsy is mandatory to exclude lichen sclerosus, lichen planus, or malignancy 5, 6
   • Consider vulvodynia (neuropathic pain without identifiable cause) 8

Critical Pitfalls to Avoid

• Do not treat Candida identified on culture in asymptomatic women 1, 2
• Do not delay biopsy when empiric treatments fail—this can result in progression to scarring or malignancy 6
• Do not assume all burning is infectious—inflammatory dermatoses require different management 6, 7
• Do not overlook vulvodynia in patients who remain symptomatic despite resolution of visible lesions 5, 8

Less Common But Important Causes

• Dermatographism with vulvar symptoms (easily diagnosed with scratch test, responds to antihistamines) 10
• Vulvar psoriasis (well-demarcated erythematous plaques) 6
• Atrophic vaginitis (especially if perimenopausal/menopausal) 4
• Behçet's syndrome, pemphigus/pemphigoid (rare but serious) 7

The key to diagnosis is systematic evaluation starting with pH and microscopy, followed by culture if needed, and biopsy when dermatological findings are present or empiric treatment fails 6, 9.