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Introduction

Lichen sclerosus (LS) is a relatively common chronic, autoimmune skin disorder involving the anogenital region, particularly in women.

  • In men, it was previously referred to balanitis xerotica obliterans (BXO), but this term should no longer be used
  • It can also exist outside of the genital area

It can occur at any age, but typically affects women over the age of 50, and to a lesser extent, children of both genders pre-puberty.

It is thought to be caused by a combination of genetic and environmental factors but the exact causes are not well understood.

Treatment typically involves a avoiding skin irritants, regular use of emollients, and topical steroids. In women, topical oestrogen may also be of benefit. Rarely, immunomodulating drugs, such as methotrexate, cyclosporine or retinoids (e.g. isotretinoin) may be used.

LS is associated with an increased risk of squamous cell carcinoma (SCC) and as such, special attention needs to be paid to skin lesions to assess their likelihood of SCC, and excision if required. The scarring caused by the lesions of LS may also result in the need for surgery – typically circumcision in men, and more complex procedures in women. In some cases, the scarring and adhesions may lead to the closing of the vagina.

Aetiology and Epidemiology

  • The cause is essentially unknown. Likely due to a combination of genetic and environmental factors
  • Genetic factors:
    • 15% of cases have a family history
  • Associated with:
    • Increased BMI
    • Coronary artery disease
    • Smoking
    • Preceding infections
    • Preceding trauma
  • About 10x more common in women
    • Affects about 3% of women and about 0.05% of men
    • Particularly rare in men circumcised in infancy
  • Usually aged >50
    • Probably related to post-menopausal reduction in oestrogen
  • Sometimes seen in pre-pubescent children
  • Associated with other autoimmune skin conditions, e.g. psoriasis, lichen planus, vitiligo
  • Assocaited with other autoimmune diseases

Pathology

  • Up to 80% of patients have extra cellular matrix protein-1 (ECM-1) antibodies
  • Not clear if these are a cause or result of the condition

Presentation

  • Lesions present as white papules and plaques
  • Affects the non-hair bearing areas of the vulva and perneum
    • Labia minora and clitoral hood can also be affected
    • ”Figure-of-8” area around the genitals and anus
  • NEVER affects the vaginal mucosa
  • Symptoms
    • Itch
      • The main symptom
      • Often worse at night and disturbs sleep
    • Dysuria
    • Dyspareunia
    • Pain when passing stool due to anal fissures
  • Can lead to adhesions and scarring
    • Scarring is permanent and destructive
    • Reduced size of opening of vagina – occasionally completely occluded
    • Reduced size of labia minora
    • Phimosis of clitoris (becomes buried by surrounding tissue)
  • In men
    • Affects the glans of the penis
    • Glans can become white, firm and scarred
    • Painful erections and/or pain on sexual intercourse
    • Urethra strictures – which may alter urinary flow
  • Extragenital manifestations
    • 10% of cases
    • >95% of extragenital cases also have genital disease
    • Small, white dry plaques – like “cigarette paper”
    • Typically on inner thigh and buttocks, but can also affect the torso and axillae
Extragenital manifestations of lichen sclerosus

Extragenital manifestations of lichen sclerosus – images taken from dermnetnz.org – licensed under a Creative Commons Attribution 3.0 Unported License

Complications

The complications of lichen sclerosis are particularly important.

Squamous cell carcinoma

  • Occurs in 5% of LS patients
  • More likely to occur if LS is poorly controlled
  • Presents as an enlarging lump that does not resolve
  • Treated either by surgical excision or cryotherapy

Diagnosis

Diagnosis is often clinical, but can be confirmed by skin biopsy if there is uncertainty.

Consider thoroughly documenting the lesions for follow-up – including with photography if the patient consents to this.

If lesions fail to respond to treatment then biopsy is essential.

Despite the association with other autoimmune diseases, there is no role for blood tests to screen for auto-antibodies or thyroid function, unless this is clinically indicated by specific symptoms of another autoimmune disorder.

Differential diagnosis

Management

Supportive measures

  • Wash gently once or twice a day
  • Use a non-soap cleanser (e.g. an emollient such as QV cream, cetaphil) or water only
  • Avoid tight clothing
  • Avoid synthetic fabrics
    • Loose fitting cotton clothing is best
  • Avoidance of certain activities
    • Cycling
    • Horse riding

Topical therapies

  • Emollients (for more about emollients in skin conditions – see eczema)
  • Topical steroids
    • Typically an ultrapotent steroid is used – such as clobetasol propionate 0.05%
    • Potent agents – e.g. mometasone fumorate 0.1% may be used in milder cases or when symptoms are under control
    • Typically once daily at night
    • A thin smear applied to the affected areas
    • Typically required for 1-3 months daily and then dose can be reduced to once or twice weekly when symptoms are under control
    • Works well to control the itch
    • Skin appearance may improve or even return to normal, but not always
    • A 30g tube should typically last 3-6 months
    • Be aware of over-use of cream
      • Red irritated skin
      • increased risk of thrush
      • Burning pain
  • Follow-up after one month to assess the effectiveness of treatment
  • Extra-genital lesions typically respond well to topical steroids
  • Topical oestrogen
    • May be tried
    • May be of some benefit in some patients
    • Of most benefit when there is also co-existing atrophic vulvovaginitis

Oral therapies

  • Reserved for resistant cases
  • Typically used under the supervision of a specialist
  • Options include:
    • Oral steroids
    • Oral retinoids – e.g. isotretinoin
    • Methotrexate
    • Ciclosporin

Surgery

  • Excision of SCCs or suspected SCCs
  • Circumcision may relieve symptoms in men
  • Surgery may be required to release adhesions and excise scar tissue in women, especially if the vaginal orifice opening is affected

Prognosis

  • Chronic and incurable
  • Most cases are well controlled with topical agents
    • Symptomatic remission is achieved in 98% of women
    • 75% men are cured by circumcision
    • 60% of men responde to ultra-potent steroids
  • Resistant cases are often associated with lichen planus
  • Extragenital lesions are less likely to be chronic and often completely resolve

Flashcard

References

  • Lichen sclerosus - patient.info
  • Murtagh’s General Practice. 6th Ed. (2015) John Murtagh, Jill Rosenblatt
  • Oxford Handbook of General Practice. 3rd Ed. (2010) Simon, C., Everitt, H., van Drop, F.
  • Beers, MH., Porter RS., Jones, TV., Kaplan JL., Berkwits, M. The Merck Manual of Diagnosis and Therapy
  • Lichen sclerosus - dermentnz

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