Lichen Sclerosus

Lichen sclerosus is a chronic relapsing inflammatory mucocutaneous disease with a predilection for anogenital skin, causing white atrophic plaques, scarring and architectural distortion. It carries a small but important risk of squamous cell carcinoma.

• It is substantially more common in women, with peaks in prepubertal girls and postmenopausal women.
• Pathogenesis is probably autoimmune with genetic predisposition and association with autoimmune thyroid disease, vitiligo, alopecia areata, pernicious anaemia and type 1 diabetes.
• Histology shows hyperkeratosis, epidermal atrophy, basal cell degeneration, a homogenised collagen band in the upper dermis and a band-like lymphocytic infiltrate.

Complications

• Vulval squamous cell carcinoma develops in a minority of patients over time.
• Scarring can cause labial resorption, clitoral hood fusion, introital stenosis, dyspareunia, meatal stenosis, urethral stricture and phimosis.
• Extragenital disease may affect the trunk, thighs, wrists and neck.

Women

• Intense vulval itching, burning, soreness, dyspareunia, dysuria and pain with defecation.
• Ivory-white or porcelain atrophic plaques, often in a figure-of-eight pattern around the vulva and anus, with fissures, purpura and erosions.
• Loss of labia minora, labial fusion, clitoral phimosis and narrowed introitus may develop.
• Persistent hyperkeratotic plaques, ulcers, erosions or a lump raise concern for malignancy.

Girls

• Itching, soreness, constipation, bleeding from fissures and dysuria, often with a perianal and vulval hourglass distribution.

Men

• White indurated plaques on the foreskin and glans, phimosis, erosions, meatal stenosis, weak urinary stream, frenulum tightening and painful erections.

Differential diagnosis includes lichen planus, vitiligo, lichen simplex chronicus, psoriasis, candidiasis, contact dermatitis, vulval intraepithelial neoplasia, cicatricial pemphigoid and Paget disease.

Red flags are non-healing ulcer, firm nodule, bleeding, hyperkeratotic plaque, fixed groin nodes and new pigmented lesions.

Diagnosis is clinical in typical cases.

Biopsy is indicated for

• Uncertain diagnosis or atypical features.
• Persistent ulcers, hyperkeratosis or lesions that fail to respond after about 3 months of treatment.
• Suspected malignancy or intraepithelial neoplasia.
• Before second-line treatment in unclear cases.

A 3 to 4 mm punch biopsy is taken from the edge of the lesion under local anaesthesia.

Additional evaluation

• Consider thyroid function and thyroid peroxidase antibodies, HbA1c, CBC and vitamin B12 testing according to associated autoimmune disease.
• Swab for candida, herpes or bacterial infection when erosions and fissures do not heal.
• Inspect for extragenital disease and examine oral mucosa if lichen planus is considered.
• Vulvoscopy or colposcopy for suspicious areas.

First-line treatment

• Clobetasol propionate 0.05% ointment once daily at night for 4 weeks, then alternate days for 4 weeks, then twice weekly for 4 weeks, followed by long-term maintenance 1 to 2 times weekly or as required.
• Long-term topical corticosteroid treatment suppresses inflammation, reduces scarring progression and lowers cancer risk.
• In children, clobetasol 0.05% once daily initially or mometasone furoate 0.1% may be used.
• In men, clobetasol 0.05% daily for 2 to 3 months, with circumcision for persistent phimosis or foreskin-confined disease.

Supportive care

• Emollients and soap substitutes, avoidance of fragranced products, tight clothing and irritants.
• Hydroxyzine 10 to 25 mg at night or chlorphenamine 4 mg for nocturnal itch when needed.
• Treat candidiasis, bacterial infection or herpes if present.
• Lubricants, vaginal dilators and pelvic floor physiotherapy for dyspareunia.
• Topical vaginal oestrogen for coexisting genitourinary syndrome of menopause.

Refractory disease

• Tacrolimus 0.1% ointment or pimecrolimus 1% can be used after steroid failure.
• Intralesional triamcinolone for thick plaques.
• Systemic options for severe or extragenital disease include methotrexate, acitretin, ciclosporin and hydroxychloroquine in selected patients.

Surgery

• Release of clitoral phimosis or adhesions, perineoplasty for introital stenosis, meatotomy or urethral reconstruction for urinary obstruction, and oncological excision when neoplasia develops.

Follow-up

• Review at about 3 months after starting treatment, then every 6 to 12 months lifelong.
• Biopsy any non-responsive erosion, ulcer, nodule or hyperkeratotic area.