Diagnosis

Lichen sclerosus

Etiology

Cause [2qy]

• Unknown cause

• Multifactorial:

  • Genetic (association with other autoimmune diseases such as alopecia areata, vitiligo, autoimmune thyroiditis, and pernicious anemia)

  • Infectious trigger (spirochetes)

  • Sex hormone

  • Koebner phenomenon

Pathophysiology [2qy]

1. Infiltration of activated T cells releasing IL-4 and TGF-β

2. Activated fibroblasts producing significantly altered collagen leading to fibrosis

3. Vascular damage by the decrease in the number of capillaries

Complications [2qy]

• Vulvar or penile squamous cell carcinoma

• Loss of genital architecture:

  • Women: Introital stenosis, fusion, and resorption of the labia minora

  • Men: Phimosis, urethral stricture

Epidemiology

Incidence per 100.000 [zt7][ybc][4cb][v1t][avs][hor]

Approach

• Clinical diagnosis: [2qy]

  • Lesion: Hypopigmentation and skin atrophy

  • Location: Commonly affecting the genital skin, less often the extragenital sites

• Dermatoscopy [avs]

• Biopsy with immunofluorescence

Treatment

1. Lifestyle changes: moisturizer, silk underwear, lubrication

2. First-line therapy:

   • Potent topical steroids (clobetasol ointment) once or twice daily for 3 months [zt7][jsy]

3. Second-line therapy:

   • Calcineurin inhibitors: tacrolimus and pimecrolimus

4. Third-line therapies: [jsy]

   • Topical or oral retinoids

   • Steroid injections

   • Cyclosporin

   • Methotrexate or hydroxyurea

   • Hydroxychloroquine < 6.5 mg/kg based on ideal body weight

   • For extragenital lichen sclerosus: phototherapy

5. If topical steroids fail in male patients --> circumcision [jsy]

6. Delayed diagnosis or steroid resistance --> genital reconstruction to restore functionality

Differential diagnoses

Acrodermatitis chronica atrophicans, Albinism, Anetoderma, Atrophoderma, Balanitis circumscripta plasmacellularis, Balanitis xerotica obliterans, Basal cell carcinoma, Candidiasis, Cutaneous T-cell lymphoma, Eczema, Graft-versus-host disease, Idiopathic guttate hypomelanosis, Leukoplakia, Lichen nitidus, Lichen planus, Morphea, Paget's disease, Pinta, Psoriasis, Scleroderma, Squamous cell carcinoma, Systemic lupus erythematosus, Tinea versicolor, Vitiligo