What are the differential diagnoses for a patient presenting with depigmented, burning, and painful areas in the vulvovaginal region?

Differential Diagnoses for Depigmented, Burning, and Painful Vulvovaginal Areas

Lichen sclerosus is the most likely diagnosis in a patient presenting with depigmented areas, burning, and pain in the vulvovaginal region, particularly if postmenopausal, and should be the primary consideration. 1

Primary Differential Diagnoses

Lichen Sclerosus (Most Likely)

• Lichen sclerosus presents with porcelain-white plaques, fragile atrophic skin, and characteristic fissures in a figure-eight pattern around the vulva and anus, which is pathognomonic for this condition. 2, 1
• Occurs most commonly in postmenopausal women (85-98% affect the anogenital area) and is characterized by intractable pruritus, vulvar soreness, dyspareunia, and fissures with bleeding 1
• The depigmentation is accompanied by architectural changes including labial fusion, buried clitoris, or introital narrowing in advanced cases 1
• Burning and pain are prominent symptoms, often with ecchymosis and purpura on examination 2, 3

Lichen Planus

• Presents with vulvar burning, soreness, and dyspareunia similar to lichen sclerosus, but is distinguished by erosive lesions rather than white plaques 1
• Erosive lichen planus shows well-demarcated, glazed red macules or patches at the labia minora, vestibule, and/or vagina, affecting hairless skin and mucocutaneous junctions 4
• May involve vaginal mucosa with potential introital stenosis, which helps differentiate it from lichen sclerosus 1
• The depigmentation is less prominent than in lichen sclerosus, with erythema and erosions being the dominant features 4

Vulvar Vitiligo

• Presents with well-demarcated depigmented patches but is asymptomatic (no burning, pain, or architectural changes) 2, 3
• Dermoscopy shows reduced pigment network or pigment absence with intralesional spots of residual pigmentation 3
• Can coexist with lichen sclerosus, making diagnosis more challenging 2, 3
• The absence of symptoms (burning/pain) in pure vitiligo is the key distinguishing feature 2

Vulvovaginal Candidiasis (Less Likely Given Depigmentation)

• Characterized by intense pruritus, external dysuria, and vulvar burning, but typically presents with thick white discharge and erythema rather than depigmentation 2, 1
• Normal vaginal pH (≤4.5) helps distinguish from other causes 1
• Diagnosis requires visualization of yeasts or pseudohyphae on wet preparation with 10% KOH 2
• Depigmentation is not a feature of candidiasis, making this less likely in this presentation 2

Other Considerations

• Inflammatory vaginitis may present with burning but typically shows erythema and purulent discharge rather than depigmentation 5
• Atrophic vaginitis in postmenopausal women causes burning and dryness but presents with pale, thin mucosa rather than discrete depigmented plaques 5
• Vulvodynia/dysesthetic vulvodynia causes burning pain but without visible depigmentation or structural changes 2, 6

Diagnostic Approach

Physical Examination Findings to Assess

• Look specifically for porcelain-white plaques, fissures, ecchymosis, and architectural changes including labial fusion, buried clitoris, or introital narrowing 1
• Assess for erosive lesions, vaginal involvement, and introital stenosis that would suggest lichen planus 1, 4
• Examine for figure-eight pattern of involvement around vulva and anus (pathognomonic for lichen sclerosus) 2, 1
• Check vaginal pH: normal (<4.5) suggests candidiasis; elevated (>4.5) suggests bacterial vaginosis or trichomoniasis 1

When to Biopsy

• Biopsy is mandatory if diagnosis is uncertain, disease fails to respond to treatment, or there is suspicion of neoplastic change 2, 1
• Biopsy all morphologically distinct areas, as disease appearance overlaps with other dermatologic, infectious, and neoplastic entities 4
• For lichen sclerosus, look for basal layer damage, band-like lymphocytic infiltrate, and absent subepithelial sclerosis 4

Critical Pitfall to Avoid

Do not assume vitiligo based solely on depigmentation—if burning and pain are present, lichen sclerosus must be ruled out, as vitiligo is asymptomatic and does not cause architectural changes 2, 3. The presence of symptoms with depigmentation strongly favors lichen sclerosus over vitiligo.