Lichen sclerosus

Lichen sclerosus is a chronic, progressive skin disorder that most commonly affects the genitalia and perianal area.

Lichen sclerosus is a chronic dermatological condition that is characterised by pruritus and irritation in the anogenital area. The condition is ten times more common in women and classically affects the labia minora and/or majora with development of white atrophic plaques that may lead to architecture destruction overtime.

Other terms:

• Lichen sclerosus et atrophicus (old term used in women)
• Balanitis xerotica obliterans (used to describe lichen sclerosus of the gland penis in men)

Lichen sclerosus is much more common in woman.

Lichen sclerosus is up to ten times more common in women and has two peaks of onset in prepubertal girls and peri- or post-menopausal woman. It may co-exist with other skin conditions and is thought to occur in 1 in 30 older woman.

The cause of lichen sclerosus is unknown.

The exact cause of lichen sclerosus is not completely understood, but it is thought to occur due to a combination of factors:

• Genetic: lichen sclerosus may be seen in family members of patients with the condition
• Immunological: lichen sclerosus is associated with other autoimmune conditions including alopecia areata, vitiligo, pernicious anaemia and diabetes mellitus. In addition, there is evidence of antibody formation against extracellular matrix protein 1 (ECM-1), which is a key dermal protein.
• Hormonal: increased incidence during low oestrogen states
• Infections: some infectious agents have been postulated to induce lichen sclerosis

In men, if circumcised in infancy, Lichen sclerosus is rare.

Lichen sclerosus predominantly affects the anogenital region in 85-98% of patients.

Lichen sclerosus is characterised by areas of thin, white skin over the anogenital region with or without distortion to the anatomy.

Symptoms

• Asymptomatic
• Pruritus
• Soreness or irritation
• Dysuria
• Dyspareunia (painful sexual intercourse)
• Anal symptoms: bleeding, fissures, painful defecation, pruritus ani.
• Painful erections (men)

Signs

Observed lesions commonly involve the labia minora and/or labia majora in woman and glans penis in men. Lesions may extend to involve the perineum and perianal region. It never involves the vaginal mucosa.

A variety of lesions may occur in lichen sclerosis.

• White atrophic plaques (typical change)
• Haemorrhagic lesions (i.e. blood blister)
• Bullae (fluid filled lesion >5mm)
• Ulcers
• Lichenification: thickening of skin due to excoriation (i.e. damage to skin surface due to scratching)
• Adhesions and scarring: can lead to distortion of the labia minora, buried clitoris or introital stenosis (narrowing of vaginal entrance)
• Phimosis: difficulty retracting foreskin in men
• Meatal stenosis: narrowing of the external urethral meatus in men

Extragenital lichen sclerosus

This may occur in up to 15% of cases (may be underestimate). Lesions tend to be asymptomatic.

• Typical sites: thighs, breasts, wrists, shoulders, back, neck.
• Appearance (white skin): typically white papules or atrophic papules
• Appearance (dark skin): hypo- or hyperpigmentatory papules

A formal diagnosis of lichen sclerosus is made from punch biopsy of the affected area.

The diagnosis of lichen sclerosus is usually suspected based on the characteristic appearance in the anogenital region, which can then be confirmed on biopsy. Biopsy is also useful at excluding dysplasia or neoplasia (see malignant risk).

Punch biopsy

A small punch biopsy from the vulva, or affected area, is usually sufficient to make the diagnosis. This may be completed in vulval or dermatology clinic.

Histology

The classic appearance of lichen sclerosus is thinning of the epidermis with or without areas of hyperkeratosis (abnormal thickening).

Other autoimmune diseases

Due to the association with autoimmune diseases, patients should be assessed for other conditions and investigations requested as appropriate.

There are a number of disorders that affect the vulva that may be confused with lichen sclerosus.

All patients should be assessed for alternative diagnoses. Some conditions may coexist with lichen sclerosus.

Other vulval lesions include:

• Lichen planus: a similar pruritic vulval disorder that is characterised by well-demarcated, erythematous patches or erosions with a white lace-like pattern. Anal involvement is rare and this condition can involve the vagina.
• Vulval dermatitis: refers to chronic irritation and pruritus of the vulva with associated erythema, fissuring and lichenification. Often involves the labia majora. Different types including contact dermatitis or atopic dermatitis.
• Lichen simplex chronicus: this refers to squamous cell hyperplasia (increased cell growth) due to chronic vulval irritation. Typically develops due to vulval dermatitis and subsequent persistent rubbing and scratching.
• Vulval psoriasis: usually appears as scaly erythematous plaques rather than white lesions.
• Vulvovaginal candidiasis: refers to vaginal thrush that can cause an intensely itchy vulva with characteristic white discharge.

Lichen sclerosus increases the risk of developing both vulval and penile squamous cell carcinoma.

In women, there is an increased risk of vulval squamous cell carcinoma, which is estimated to be <5%. There may be evidence of an early precursor lesion to squamous cell carcinoma known as vulvar intraepithelial neoplasia (VIN). VIN is also associated with human papilloma virus infection (HPV) and can be diagnosed on biopsy.

Women with lichen sclerosus should have the area of skin examined at least annually and non-resolving lesions biopsied, particularly hyperkeratotic areas.

In men, there is an increased risk of penile squamous cell carcinoma, but this is rare (~1%). Extragenital sites of lichen sclerosus do not seem to predispose to cancer.

Lichen sclerosus is a chronic, progressive condition that can significantly impair quality of life.

All patients with anogenital lichen sclerosus should be considered for treatment to prevent progression, which can result is sexual dysfunction and disfigurement. This includes asymptomatic patients.

Conservative management

Patient education and support is vital and patients should be referred to a clinician with a specialist interest. Basic management such as good hygiene (wash gently at least once a day), use of non-soap cleaners, avoidance of tight clothing and reduce scratching/rubbing is pertinent for all patients.

Medical management

The main treatment is topical steroids with emollients to manage dryness.

• Emollients: this refers to moisturisers that soften the skin and reduce irritation (e.g. E45, diprobase, ZeroAQS, Cetraben). Emollients may come as lotions, creams or ointments that differ in the proportion of oil to water. Can be applied multiple times.
• Topical corticosteroids: potent topical steroids (e.g. clobetasol propionate 0.05% ointment) may be prescribed initially once a day for 6-12 weeks and then reassess. Long-term treatment may be required.
• Intralesional corticosteroids: injection of some preparations of corticosteroids may be used for thickened areas that fail to respond to topical therapy.
• Topical calcineurin inhibitors: this is an immunosuppressive agent that is second-line treatment.
• Other therapies: oral/topical retinoids and UVA1 phototherapy can both be used. Oestrogen pessaries or creams may be used to reduce symptoms of atrophic vulvovaginitis in post-menopausal women that may be contributing to symptoms.

Corticosteroids are highly effective for lichen sclerosus, therefore, treatment failure should warrant investigation for an alternative cause. This is particularly true before moving to second-line therapies.

Reasons for treatment failure:

• Poor adherence or technique with topical steroids
• Superinfection: commonly bacterial or fungal (e.g. candida)
• Alternative diagnosis
• Underlying malignancy
• Atrophic vulvovaginitis due to menopause

Surgical management

Surgery is generally reserved for patients with evidence of high-grade dysplasia, malignancy or significant adhesions/scarring. In men, circumcision is highly effective with prepuce involvement or phimosis.

Patients with lichen sclerosus require long-term follow-up.

Due to the progressive nature of the disease, patients with lichen sclerosus are at risk of malignancy, chronic adhesions and scarring. They require long-term follow-up and ongoing treatment as needed.