Vulvar lichen planus

Definition

• Vulvar lichen planus is a chronic autoimmune disease affecting the skin and mucous membranes, including the vulva and vagina.

Classification

• Three vulvar variants are distinguished: classic papulosquamous, hypertrophic and erosive; the erosive form is the most common.
• The hypertrophic form shows hyperkeratotic lesions that can mimic squamous cell carcinoma.

Occurrence & epidemiology

Epidemiology

• Mostly women in their fifth or sixth decade are affected; the erosive form does not occur in children.
• Up to 68 % of women with erosive vulvar lichen planus also have oral involvement; the erosive form is associated with other autoimmune diseases, most often thyroid disease.

Aetiopathogenesis

Aetiology and risk factors

• T-cell-mediated destruction of keratinocytes in the basal layer is thought to be the basis; the exact cause is unclear.

Clinical features

• The erosive form causes pain, dyspareunia and dysuria, non-erosive forms typically pruritus; vaginal involvement may cause discharge.
• Vulvar and vaginal lichen planus can also be asymptomatic.
• The erosive form can alter the normal architecture; vaginal adhesions, stenosis and, in severe cases, complete closure of the vaginal canal may develop.
• Vulvovaginal-gingival syndrome is a form of erosive lichen planus involving the vulva, vagina and mouth and often causes scarring.
• Vulvar lichen planus is associated with squamous cell carcinoma.

Diagnosis

• The classic form shows violaceous papules or plaques with white reticulation (Wickham striae), the erosive form erosions with a white lacy edge, often on the medial labia minora and vaginal orifice.
• Histology shows a lymphocytic, lichenoid dermatitis; wedge-shaped hypergranulosis, numerous cytoid bodies and pointed rete ridges favour lichen planus over lichen sclerosus.
• In the erosive form, a biopsy may be non-diagnostic because of loss of the epidermis.

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Further reading (selection)

1. Lichenoid vulvar disease: A review (Int J Womens Dermatol 2017, PubMed Central)

Cross-references