Lichen Sclerosus (Genital)

Risk factors

• Female sex (10:1)
• Postmenopausal or prepubertal age
• Personal or family history of autoimmune disease
• HLA-DQ7 and HLA-DR12 associations
• Chronic irritation, occlusion, urine exposure
• Lack of circumcision in males (most cases occur in uncircumcised individuals)

Pathophysiology

Likely autoimmune, T-cell mediated dermatitis with epidermal atrophy, basement membrane thickening, and a homogenized hyalinized upper dermal collagen zone overlying a lichenoid lymphocytic infiltrate. Anti-extracellular matrix protein 1 (ECM1) antibodies have been described. The result is loss of elasticity, fibrosis, and scarring.

Clinical presentation

Differential diagnosis

• Vitiligo — Depigmented macules without atrophy, scarring, or symptoms; loss of melanocytes on biopsy
• Lichen planus (erosive) — Painful violaceous papules with Wickham striae; oral involvement common; lichenoid inflammation without homogenized dermis
• Atrophic vulvovaginitis (genitourinary syndrome of menopause) — Diffuse thinning and dryness without porcelain plaques or architectural loss; responds to topical estrogen
• Candidiasis — Erythema, satellite pustules, white curdy discharge; KOH positive; responds to antifungals
• Sexual abuse (in pediatric patients) — Must be considered; LS can mimic; appropriate history, exam, and reporting required
• Vulvar intraepithelial neoplasia / SCC — Persistent leukoplakia, erosion, or nodularity within LS; biopsy any non-healing or new lesion

Diagnostic workup

Diagnostic algorithm

flowchart TD
  A[Genital pruritus<br/>and white plaques] --> B[Clinical exam<br/>± biopsy if atypical]
  B --> C{Lichen sclerosus<br/>confirmed?}
  C -->|Yes| D[Clobetasol 0.05% oint<br/>QHS x 4-12 wk]
  C -->|No| E[Reassess differential]
  D --> F[Taper to maintenance<br/>1-3x/wk]
  F --> G[Annual surveillance<br/>for SCC]
  D --> H{Refractory or<br/>steroid-intolerant?}
  H -->|Yes| I[Tacrolimus 0.1% oint]
  H -->|No| J[Continue maintenance]
  G --> K{New nodule,<br/>ulcer, or<br/>hyperkeratosis?}
  K -->|Yes| L[Biopsy to exclude<br/>VIN / SCC]
  K -->|No| F

Treatment

Complications

• Permanent architectural change (clitoral burying, labial resorption, introital stenosis, phimosis, meatal stenosis)
• Sexual dysfunction, painful intercourse, voiding difficulty
• Squamous cell carcinoma of the vulva or penis (lifetime risk 4-6% in women with LS; lower but increased in men) — necessitates lifelong dermatologic/gynecologic surveillance
• Skin atrophy from prolonged ultrapotent topical steroid use, particularly when not tapered to maintenance
• Psychological burden: anxiety, depression, body image distress

PANCE pearls

• Lichen sclerosus is the only chronic vulvar disease in which adequately treated patients have a substantially reduced risk of progression to vulvar SCC — undertreatment is the main danger, not overtreatment.
• Ultrapotent topical steroids (clobetasol) are safe long-term in this disease when properly used; do not under-dose for fear of atrophy in genital LS.
• Always biopsy persistent ulcers, eroded plaques, or new nodules — SCC arises on a background of LS.
• Consider sexual abuse on the differential in pediatric LS, but recognize that LS itself can mimic abuse and a multidisciplinary evaluation is appropriate.
• Circumcision is often curative in male LS limited to the foreskin.
• Reassure patients that LS does not have to mean inevitable scarring — early, aggressive, sustained therapy can preserve architecture.

References

• BAD 2018 — Lewis FM et al. British Association of Dermatologists guidelines for the management of lichen sclerosus (BJD 2018)
• ACOG — ACOG Practice Bulletin No. 224: Diagnosis and Management of Vulvar Skin Disorders (Obstet Gynecol 2020)
• European Academy — Kirtschig G et al. Evidence-based (S3) guideline on (anogenital) lichen sclerosus (EADV 2015)