Lichen Sclerosus

Synonyms: White spot disease, Csillag's disease, Lichen albus, Lichen sclerosus et atrophicus, Balanitis Xerotica Obliterans, Kraurosis vulvae

This chronic inflammatory dermatosis usually affects the skin of the anogenital region in women, and the glans penis and foreskin in men (balanitis xerotica obliterans - BXO). It occurs less commonly in extra-genital areas. It does not cause any systemic disease outside the skin. Its aetiology is unknown.

There are no reliable figures for population incidence or prevalence. Rates of BXO vary depending on whether or not circumcision is practised in a society (it is exceedingly rare in circumcised men).
It most often affects adult women in their fifth and sixth decade.¹
Female: Male ratio is about 7:1. Children may also be affected (about 15% of cases) and it is an important differential diagnosis of the signs of suspected sexual abuse.²

The primary histological abnormality is inflammation, with abnormally active fibroblasts in the papillary dermis. Genetic, autoimmune and infective mechanisms have been postulated but no definitive proof has ever been found. Latest theories focus on the role of oxidative damage to lipids, DNA and proteins within the epidermis.³

The condition may be asymptomatic and discovered during assessment for another problem. Usually intractable itching and soreness of the genitals (85% of cases). White polygonal plaques develop on the skin and merge to form shiny, white plaques. There are also comedo-like plugs and 'dells' seen before the plaque formation has occurred.

Female

• There may be an hourglass shape of inflamed/damaged skin around the vulva and anus.
• Dysuria, dyspareunia and pain on defecation are common.
• There may be traumatic tearing of the skin during intercourse or defecation.
• Destructive scarring is common; the labia minora may fuse making micturition difficult, and the introitus can become very narrow.
• Occasionally it presents before puberty, where the 'bruised' red, purpuric signs appear to suggest abuse to the unwary, particularly if there are bullae, erosions, and ulcerations.

Male

• Lichen sclerosus (BXO) usually affects the glans penis and foreskin - but generally not the perianal region.
• As well as soreness and itching, there may be difficulty in retracting the foreskin and a poor urinary stream.
• Pale atrophic or sclerotic plaques and accompanying balanitis.
• Often a non-retractile foreskin necessitating circumcision.
• Lichen sclerosus commonly recurs in the circumcision scar.

Extra-genital disease

Lichen sclerosus affects extra-genital sites in 15-20%. The Koebner phenomenon may occur. Disease arises in scars, burned or repeatedly traumatised skin. Rarely, it may affect the oral mucosa. Pruritus of extra-genital form is unusual. Extra-genital lesions may require no therapy if asymptomatic or not causing significant cosmetic effect. There is no increased risk of squamous cell carcinoma in extra-genital lesions.

Skin punch biopsy is useful to confirm the diagnosis and exclude malignancy. Histology typically shows degeneration of the basal cells and a pale-staining homogeneous zone in the epidermo-dermal junction, with a band of mainly monocytic inflammation beneath.
Check:

• FBC
• Glucose
• Thyroid function
• Swab skin if infection is suspected

• Localised scleroderma (morphoea)
• Vitiligo
• Lichen planus
• Benign leucoplakia
• Pemphigus/pemphigoid
• Graft-versus-host disease
• Amyloidosis
• Post-radiation dermatitis
• Squamous cell carcinoma
• Discoid lupus erythematosus
• Lichen simplex
• Pityriasis versicolor
• Other causes of balanitis

Non-Drug

Advise patients to wash with bland emollients e.g. aqueous cream, to avoid topical irritants and tight clothing, to use lubricants if necessary and give details of support groups. Warn patients that non-healing erosive or warty lesions may indicate cancerous change.
Patients may suffer psychosexual problems; get help to overcome these from a psychologist/psychiatrist or appropriate counsellor.

Drug

• Judicious use of carefully-applied potent topical steroid e.g. Clobetasol propionate 0?05% ointment. Given once daily for 1-2 months, gradually reducing to zero. There is no evidence to support the use of a particular potent steroid or any given regimen. Pharmacodynamic studies have shown that the ointment does not need to be given more than once daily.⁴
• A 6-8 week course of ultrapotent topical corticosteroid is a safe and effective treatment for genital lichen sclerosus in paediatric patients,⁵ although spontaneous resolution may occur.² Care must be taken to use potent steroids as judiciously as possible in children to avoid growth suppression.
• Potent steroids should always be used with caution.
• Treatment then usually given on a PRN basis, certainly <30g per 3 months.
• The British Society of Dermatologists suggest that ideally all women with ano-genital lichen sclerosus should be seen by a dermatologist at least once,⁶ although this recommendation pre-dates GPs with special interest.
• GPs have an important role in monitoring the condition and referring back to dermatologist when there is reason to suspect recurrence.
• Cyclosporin has been shown to be of no benefit.
• Retinoids appear to help in complex cases.
• Potassium para-aminobenzoate has been shown to help anecdotally in severe cases.⁴
• Testosterone cream, once the mainstay of therapy, has been shown to be no more effective than simple emollients.^7,4

Surgery

Surgical procedures are sometimes warranted, although vulvectomy is not indicated unless there is a tumour. Phimosis needs circumcision. Surgery may be needed in women to repair damage by scarring (e.g. division of fused labia or enlargement of introitus). Follow-up with topical steroids and dilators is needed to prevent recurrence.
BXO involving anterior urethra is a devastating disease, and patients often require several complex surgical procedures to control it. An alternative approach is to accept that damage is inevitable and to form a perineal urethrostomy to allow seated voiding.⁸

With early and careful management in conjunction with dermatology/gynaecology/urology, the extreme burden of this disease is lessening and many patients lead happy lives with normal urinary and sexual function. However, the course is highly variable and some patients will inevitably be severely affected. There is a 4-5% risk of squamous-cell carcinoma (SCC) of the vulva, and there may be a slightly increased risk of SCC of the penis. Long term follow-up is advisable, biopsy any suspicious lesions. Extra-genital lesions do not appear to have any increased risk.