Lichen Simplex, Planus and Sclerosis

Question 1

Definition of lichen simplex

Answer 1

Also called chronic vulval dermatitis. Localised plaque of eczematous inflammation created by repeated scratching/rubbing of skin

Question 2

Four main underlying causes of lichen simplex

Answer 2

Underlying dermatoses- atopic dermatitis, allergic contact dermatitis, superficial fungal (tinea and candidiasis) infections
Systemic conditions causing pruritis- RF, obstructive biliary disease (PBC, PSC), polycythaemia
Environmental factors- heat, sweat, rubbing of clothing and other irritants such as harsh skincare products
Psychiatric disorders- anxiety, depression, OCD and dissociative experiences, emotional tensions

Question 3

Presentation of lichen simplex

Answer 3

• Vulval itch and soreness. Severe intractable pruritis, especially at night
• Skin will show lichenification (thickened, slightly scaly, pale or earthy-coloured skin with accentuated markings, may be more marked on opposite side to dominant hand), erosions and fissuring, excoriations, loss of pubic hair
• Labia majora may be inflamed and thickened
• Can be complicated by secondary infection

Question 4

Investigations for lichen simplex

Answer 4

Clinical diagnosis and history including MSE where indicated.
General examination of the skin to look for psoriasis and lichen simplex elsewhere
Screen for infection including Staphylococcus aureus, Candida albicans
Dermatology referral for consideration of patch testing

Question 5

Management of lichen simplex

Answer 5

• Identify and avoid precipitating factors, CBT may be useful where there is underlying anxiety etc.
• Consider prescribing a potent topical corticosteroid ointment (such as betamethasone), for 1–2 weeks to break the itch scratch cycle and bring the condition under control.
• Consider prescribing a mildly anxiolytic antihistamine (for example hydroxyzine) for use at night
• Recommend an emollient as a soap substitute.
• Follow up as required (within 1 month for severe disease)

Question 6

Definition of lichen planus

Answer 6

An inflammatory condition with manifestations on the skin, genital and oral mucous membranes. Appears as erosive glazed or glossy erythematous plaques. Also more rarely affects the lacrimal duct, oesophagus and external auditory meatus.

Question 7

Pathogensis of lichen planus

Answer 7

• The pathogenesis is unknown but it is an autoimmune disease, likely caused by the immunological response of T cell to an unknown antigen. Weak circulating basement membrane zone antibodies are present in 61% of erosive lichen planus of the vulva
• Affects all ages and is not linked to hormonal status
• Associated with loss of vulval architecture and increased incidence of SCC

Question 8

Presentation of lichen planus

Answer 8

• Pruritis, irritation and soreness of the vulva, may be associated lesions in the mouth
• Superficial dyspareunia
• Vaginal discharge
• Urinary symptoms
• Typical papules are itchy, shiny, purle and flat topped. Typical plaques are erosive glazed or glossy and erythmatous.

Question 9

Appearance of classical lichen planus

Answer 9

• Typical papules (itchy, shiny, purple, flat-topped papules) will be found on the keratinised anogenital skin, with or without striae on the inner aspect of the vulva.
• Hyperpigmentation frequently follows their resolution, particularly those with dark-skin. This type of lichen planus may be asymptomatic.

Question 10

Appearance of hypertrophic lichen planus

Answer 10

These lesions are relatively rare and can be difficult to diagnose. They particularly affect the perineum and perianal area, presenting as thickened warty plaques which may become ulcerated, infected and painful. Because of these features, they can mimic malignancy. They do not appear to be accompanied by vaginal lesions.

Question 11

Appearance of erosive lichen planus

Answer 11

• The most common subtype to cause vulval symptoms. The mucosal surfaces are eroded.
• At the edges of the erosions the epithelium is mauve and a pale network (Wickham’s striae) is sometimes seen.
• The lesions consist of friable telangiectasia (dilated blood vessels) with patchy erythema which are responsible for the common symptoms of postcoital bleeding, dyspareunia and a variable discharge which is often serosanguinous.

Question 12

Histological findings of a vulvar biopsy in lichen planus

Answer 12

Irregular saw-tooth acanthosis, increased granular layer and basal cell liquefaction

Question 13

Investigations for lichen planus

Answer 13

• Biopsy is necessary if the diagnosis is uncertain or if there is coexistent VIN/ SCC is suspected
• Screening for other autoimmune disease, especially in the thyroid
• Skin swab- to exclude any secondary infection, especially in excoriated lesions

Question 14

Management of lichen planus

Answer 14

• Patients should be made aware of the small risk of neoplastic change.
• Ultra-potent topical steroids e.g. Clobetasol proprionate (specialist care)- may also give maintenance regimen of weaker steroid preperations
• Patients should be followed up after 2-3 months to assess the response to treatment (requires long term specialist follow-up)

Question 15

Lichen sclerosis definition

Answer 15

A destructive inflammatory condition affecting the anogenital area, most often in people aged >50. Can occur anywhere between the vagina and anus can be affected (the vagina is spared)

Question 16

Pathogenesis of lichen sclerosus

Answer 16

Auto-immune factors may be involved in its pathogenesis and recent evidence has shown autoantibodies to extracellular matrix protein 1. There is an increased frequency of other autoimmune disorders in females with lichen sclerosus (particularly vitiligo and thyroid disease)

Question 17

Presentation of lichen sclerosus

Answer 17

• Severe pruritis, which is worse at night
• Scratching leads to trauma and bleeding, discomfort, pain, dyspareunia and sexual dysfunction
• Constipation can occur as a result of perianal involvement

O/E:
* Pale, white atrophic areas of affected vulva
* Pink white papules which coalesce to form parchment-like skin with fissures
* Inflammatory adhesions which can lead to fusion of the labia and narrowing of the introitus
* Loss of architecture may be manifest as loss of the labia minora and/or midline fusion. The clitoral hood may be sealed over the clitoris so that it is buried

Question 18

Main complication of lichen sclerosus

Answer 18

Leads to vulval carcinoma in 5% of cases

Question 19

Investigations for lichen sclerosus

Answer 19

• Clinical diagnosis
• Biopsy is mandatory if the diagnosis is uncertain or there are features or coexistant VIN/SCHistology will show: thinned epidermis with sub-epidermal hyalinization and deeper inflammatory infiltrate
• Investigation for autoimmune disease if clinically indicated, especially thyroid dysfunction
• Skin swab: only useful to exclude co-existing infection