Lichen simplex of the vulva

What is lichen simplex of the vulva?

Lichen simplex of the vulva is a pruritic form of dermatitis in which excessive scratching or rubbing leads to lichenification. Characteristically, there are well-demarcated, erythematous or hyperpigmented, thickened plaques affecting one or both sides of the vulva. Lichen simplex is typically secondary to an underlying skin condition or neuropathy causing a severely itchy vulva.

Lichen simplex is also known as lichen simplex chronicus and neurodermatitis.

(See our page of vulval lichen simplex images).

Who gets lichen simplex of the vulva?

Vulvar lichen simplex is most frequently seen in adult women with atopic sensitive skin.

What causes lichen simplex of the vulva?

The mechanism of lichen simplex of the vulva is explained by the persistent itch–scratch cycle. Pre-existing itch or pruritic conditions induce habitual scratching, which gives rise to histological acanthosis (thickening of the epidermis) and hyperkeratosis (thickening of the stratum corneum). Pruritus may be associated with underlying systemic disease and/or a predisposing psychiatric condition.

Contributing factors to vulval lichen simplex may include:

• Underlying atopic dermatitis
• Another pruritic skin disorder (eg, psoriasis or lichen planus)
• Contact with an irritant (irritant contact dermatitis) — often triggered by heat, sweating, chafing from clothing, or the excessive use of cleansers or topical medicaments)
• Contact with an allergen (allergic contact dermatitis)
• Cutaneous fungal infection (candidiasis or tinea)
• Psychiatric disorder (eg, anxiety or obsessive–compulsive disorder)
• A benign or malignant skin tumour (eg, squamous cell carcinoma)
• Localised neuropathic itch
• A systemic cause of generalised itch (eg, renal failure, obstructive biliary disease, hyperthyroidism or hypothyroidism, or Hodgkin lymphoma).

What are the clinical features of lichen simplex of the vulva?

Lichen simplex of the vulva manifests as well-demarcated, markedly thickened plaques with a leathery appearance. It is often unilateral but it may also be bilateral. There may be a solitary plaque or multiple coalescing plaques or papules. There is unremitting pruritus. Other commonly observed features include:

• Excoriations or linear fissures at skin folds
• Exaggerated skin lines
• Hypopigmentation or hyperpigmentation of vulval or perianal skin
• Sparse hair or broken-off hair shafts
• Varying degrees of erythema
• Oedema.

Signs of an underlying skin disorder may also be noted adjacent to the lichen simplex of the vulva and/or on another body site.

Lichen simplex can affect other parts of the body. Common sites of involvement are the posterior-lateral neck, the scalp, the extensor surfaces of extremities, and the ankles or lower legs.

What are the complications of lichen simplex of the vulva?

Complications of lichen simplex of the vulva may include:

• Insomnia or poor quality of sleep — sleep studies have revealed sleep disturbances due to scratching when asleep
• Secondary infection (eg, impetigo or cellulitis)
• Postinflammatory hyperpigmentation or hypopigmentation and, rarely, permanent white marks (leukoderma)
• Fibrosis and scarring from repeated scratching
• Structural distortion (rarely).

Adverse effects from treatment can also arise, particularly atrophy due to the extended use of a potent topical corticosteroid on vulval skin. Topical steroids can also cause pigmentation abnormalities.

How is lichen simplex of the vulva diagnosed?

The clinical features of vulval lichen simplex are generally sufficient to establish the diagnosis. When findings are atypical, further tests can be considered to make a definitive diagnosis or to exclude other similar dermatoses; such tests to be considered include:

• A skin biopsy to rule out squamous cell carcinoma, vulval intraepithelial neoplasia or extramammary Paget disease
• A skin swab for bacteria and candida
• Fungal scraping for dermatophyte fungus
• Patch testing, if allergic contact dermatitis is suspected.

If the vulval lichen simplex is associated with generalised pruritus, a workup for systemic causes can be undertaken (as outlined on our pruritus page).

What is the differential diagnosis for lichen simplex of the vulva?

Other disorders that should be considered in a patient with lichen simplex of the vulva include:

• Lichenified atopic eczema
• Tinea cruris
• Prurigo nodularis
• Lichen planus
• Psoriasis
• Lichen sclerosus
• Mycosis fungoides
• Extramammary Paget disease
• Condyloma related to human papillomavirus (HPV)
• Skin lesions, tumours and cancers
• Lumbosacral radiculopathy.

What is the treatment for lichen simplex of the vulva?

Treatment for lichen simplex of the vulva involves:

• Avoiding exacerbating factors
• Breaking the itch–scratch cycle
• Treating any underlying dermatosis or predisposing condition
• Re-establishment of the normal skin barrier.

Short-term topical corticosteroids are used as first-line therapy to break the itch–scratch cycle. Treatment principles for lichen simplex of the vulva include using a medium–potency topical steroid (such as triamcinolone ointment) until there is a resolution of active lesions. If the disease is refractory after 2–3 weeks of an intermediate-strength corticosteroid, more potent topical steroids can be used on a short-term basis. As the condition improves, the application frequency and potency of the corticosteroid should be decreased to minimise the adverse effects.

Other treatment recommendations include those below.

• Avoid precipitating factors such as dryness, sweating or excessive moisture, and skin irritation from tight clothes and rough materials.
• Silk or cotton fabric underwear can be less irritating to vulval skin than synthetic fabrics; however modern fibres that keep moisture away from the skin may be preferred.
• Discontinue using soap and non-prescribed topical products, and avoid using wet wipes. Emollients and barrier cream can help reduce dryness and irritation.
• Identify and treat any underlying inflammatory dermatosis, infection, or systemic cause of itch.
• Psychiatric disorders, such as depression, anxiety, or obsessive–compulsive disorder, should be treated with appropriate pharmacotherapy (eg, tricyclic antidepressants or selective serotonin reuptake inhibitors) and psychological therapy.
• Radiculopathy may be managed with tricyclic antidepressants (such as amitriptyline) or antiepileptic medications.

What is the outcome for lichen simplex of the vulva?

Lichen simplex of the vulva runs a chronic clinical course with exacerbations and remissions. As recurrences occur during psychological stresses or with the flare-up of underlying dermatoses, long-term management may be required in some patients.