Pruritus Vulvae

Vulval dermatitis

Vulval dermatitis encompasses atopic dermatitis, contact dermatitis and seborrhoeic dermatitis. Collectively, these are the most common cause of pruritus vulvae. Vulval dermatitis is frequently seen in women with eczema or a history of atopy; iron deficiency is also associated with vulval dermatitis. In addition, the vulval skin can become sensitized to a wide variety of products acting as either irritants or allergens (Box 2). In particular, urinary and faecal incontinence are irritating to vulval skin and may not be disclosed automatically, so ask specifically about this.

Severe vulval itching is the main symptom. On examination, there is swelling and redness of the vulva; the inner thighs and mons pubis may also be inflamed. Scratching exacerbates the problem further, leading to lichen simplex chronicus, with thickening and whitening of the skin, and exaggerated skin markings.

Management is aimed at avoidance of potential allergens and irritants and general care of the vulva (Box 3). Topical steroids are helpful in breaking the itch-scratch cycle, and sedating antihistamines at night are useful if nighttime scratching is a problem.

The potency of steroid chosen depends on the severity of symptoms. In milder cases, 1% hydrocortisone can be used for 2–4 weeks and then reviewed. In cases of lichenification or severe itching, potent steroids (e.g. betamethasone valerate 0.1%) may be needed for 1–2 weeks initially to break the itch-scratch cycle. The patient can then be stepped down to moderate steroids once symptoms are controlled. If symptoms persist despite avoidance measures and topical treatment, consider referral to dermatology for patch testing.

Lichen sclerosus

Lichen sclerosus is an inflammatory dermatosis mainly affecting the genital skin. It is thought to have an autoimmune basis, and approximately 30% of women with lichen sclerosus have, or will develop, another autoimmune disease, especially thyroid disease. Lichen sclerosus can affect women of any age, but peaks of incidence are seen in childhood and in postmenopausal women.

The typical symptom is intractable itching, but fissures and erosions may cause soreness. As well as affecting the vulva, lichen sclerosus can extend to involve the perianal skin, giving a figure-of-eight pattern. Affected skin appears white and wrinkled, with areas of telangiectasia and purpura (Fig. 1). Ongoing inflammation results in scarring and loss of normal architecture, giving rise to symptoms of dyspareunia and difficulty with micturition. The clitoris may become buried; there may be fusion and then loss of the labia minora and introital narrowing. Perianal disease can cause constipation.

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Figure 1.

Vulval lichen sclerosus.

Treatment is with very potent topical steroids (e.g. clobetasol propionate), which are commonly initiated in primary care based on a clinical diagnosis of lichen sclerosus. There is usually a rapid response to topical steroids. Patients who fail to respond to treatment within 2–3 weeks or those with atypical features should be referred to secondary care for confirmation of the diagnosis, which may involve a vulval biopsy. A small proportion of women do not respond to very potent topical steroids, in which case topical tacrolimus may be started in secondary care.

Lichen sclerosus has a chronic relapsing course, and women often need to use topical steroids for many years. There may be an increased risk of squamous cell carcinoma in areas of lichen sclerosus (Carli et al., 1995), and patients should be made aware of this risk. Thus, women with lichen sclerosus should have an annual review and be advised to report any change in the appearance of the vulval skin in between review visits.

Lichen planus

Lichen planus is an inflammatory skin disorder of unknown cause that can affect any part of the skin, including the vulva. Affected women may complain of vulval soreness or pain in addition to itching. The classical appearance of purple polygonal papules seen on keratinized skin is seen less commonly on the vulva. Instead, vulval lichen planus tends to be erosive with discrete erythematous edges (Fig. 2). Unlike lichen sclerosus, lichen planus can involve genital mucosa, often with a white lacy appearance.

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Figure 2.

Vulval lichen planus.

Lichen planus is also thought to be autoimmune in nature, and treatment is with very potent topical steroids to control the itching. Patients with vulval lichen planus appear to be at increased risk of developing squamous cell carcinoma (Kennedy et al., 2008), so again, annual review of affected patients is indicated.

Vulval psoriasis

Psoriasis affecting the vulval skin causes well-demarcated red patches, but the scale seen elsewhere on the body is often absent (Fig. 3). It may extend to involve the natal cleft but does not involve the vaginal mucosa. It is more common in patients with psoriasis elsewhere and those with a positive family history. Treatment is as for flexural psoriasis and includes emollients, vitamin D analogues and topical steroids. Coal tar should not be used on the vulva.

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Figure 3.

Vulval psoriasis.

Other dermatological causes

Hidradenitis suppurativa is a chronic inflammatory condition of the apocrine sweat glands, affecting the axillary and anogenital regions, including the vulva. It causes deep nodules, which can rupture to form sinus tracts, leads to widespread scarring and may present with pruritus. Treatment is with skin hygiene measures and long-term antibiotics such as doxycycline 100 mg daily for 6 months.

Behçet's syndrome is a multisystem disorder, which causes genital and oral ulceration. Genital ulcers can involve the vulval skin and tend to be painful rather than itchy. Referral for specialist treatment is required.

Vulval intraepithelial neoplasia

VIN describes a premalignant condition that has a risk of progression to squamous cell carcinoma. There are two types of VIN: usual and differentiated.

Usual type VIN tends to affect younger women (aged 35–55 years) and is particularly associated with human papilloma virus (HPV) infection. Consequently, it is more common in women who have had previous abnormal cervical cytology and is associated with intraepithelial neoplasia at other genital sites (e.g. vagina, anal skin). Other risk factors include smoking and immunosuppression. Usual type VIN has a very variable appearance and tends to affect multiple areas of the vulva. Lesions may be white, red or pigmented and warty, nodular or eroded.

Differentiated VIN affects an older age group (55–85 years) and is seen less commonly. It is not HPV related and instead is associated with chronic dermatoses such as lichen sclerosus and lichen planus. It tends to present as a single lesion, usually an ulcer or plaque.

All patients with suspected VIN should be referred to secondary care as a vulval biopsy is required for diagnosis. The gold standard for management is surgical excision. Other management options include laser and topical imiquimod cream (an immune modulator). These may be preferred as vulval anatomy can be preserved. Long-term follow-up with annual surveillance in secondary care is important, especially for those women not treated surgically.

Vulval cancer

Squamous cell carcinoma of the vulva usually presents as a lump or ulcer and in itself is not usually itchy. The National Institute for Health and Clinical Excellence (NICE) guidelines for referral for suspected vulval cancer (2005) are shown in Box 4.

Candidiasis

Acute vulvovaginal candidiasis is easily recognizable, causing vulval itching, vaginal discharge and dysuria. On examination, there is swelling and erythema of the vulva and a thick curdlike vaginal discharge. In recurrent or chronic candidiasis, however, vaginal discharge may be absent. There may be secondary sensitization of the vulval skin due to chronic application of topical antifungal creams. On examination, the vulval inflammation may be seen to extend to the thighs and mons pubis, with satellite lesions.

Where chronic vulvovaginal candidiasis is suspected, it is important to confirm the diagnosis with vaginal swabs. Treatment can be with topical or oral antifungals, with the latter having the benefit of avoiding the sensitization seen with topical therapy.

Other infective causes

Bacterial vaginosis tends to present with a fishy smelling profuse vaginal discharge, and while mild vulval irritation may be present, it is not usually the primary symptom.

Trichomoniasis can cause a vulvovaginitis and so may present with vulval itch and discharge. The diagnosis and management of these infections are covered in detail in a previous issue of Innovait (Seepana and Allamsetty, 2009).

Patients with infestations of scabies or pediculosis pubis may present with vulval irritation. Threadworms more commonly cause pruritus ani, but vulvovaginitis may also occur.

Atrophic vaginitis

In perimenopausal and postmenopausal women, the fall in oestrogen levels causes thinning and dryness of the vulva and vagina, leading to symptoms of vulval itching, dryness and dyspareunia. On examination, the vagina appears pale and dry, and the vulva is atrophic. Treatment is with topical or intravaginal oestrogens, reviewed after 3 months.

Breastfeeding women may present with similar symptoms. In this case, low oestrogen levels are due to the antagonistic effect of raised prolactin.

Systemic causes

Any condition which causes generalized pruritus may cause vulval itching. This includes conditions such as renal or liver impairment, iron deficiency, diabetes and thyroid dysfunction.

History

When seeing patients with vulval itch, a thorough history will be helpful in establishing the likely cause of symptoms. As there is often a delay in presentation, it is important to establish why the woman is presenting now and what her concerns are. Pruritus vulvae can have a major effect on a woman's life, so ask about this specifically, especially with regards to sleep and sexual function. The key points in the history are summarized in Box 5.

Ask about duration of symptoms, any specific triggers and what she has tried already. Ask directly about urinary or faecal incontinence as women may not disclose this. Enquire about any history of skin disease and symptoms at other sites. It is important to take a sexual, gynaecological and medical history. The family history should focus on the presence of autoimmune disease and atopy in family members.

Examination

As for all intimate examinations, you should offer a chaperone and ensure the patient's privacy and dignity. The woman should ideally be examined with a good light source on an examination couch. The vulva should be examined systematically, followed by inspection of the perianal region and natal cleft. Where VIN is suspected or the patient has complained of vaginal discharge, a speculum examination should be done.

Also, examine other skin sites, especially those affected by certain skin diseases, e.g. scalp and extensor surfaces for psoriasis. The oral mucosa should be examined for lichen planus, and the nails should be examined for signs of psoriasis.

Investigations

Often, the cause of pruritus vulvae is apparent after history and examination. Further investigations may be indicated depending on the suspected cause.

If infection is suspected, take swabs. Check a fasting blood glucose if diabetes is suspected. Thyroid function tests should be done in patients with lichen sclerosus, and serum ferritin should be tested in women with vulval dermatitis.

Further investigations may be undertaken in secondary care. Patch testing for patients with contact dermatitis may help identify a specific irritant or allergen and facilitate avoidance measures. A biopsy of vulval skin may be taken if VIN is suspected, if the diagnosis is uncertain or where the patient does not respond to treatment.

Management

Management of pruritus vulvae depends on treating the underlying cause. Most patients benefit from general advice regarding care of the vulval skin. Referral to secondary care is indicated for confirmation of the diagnosis in cases of suspected VIN. In other patients, referral should be considered if the underlying diagnosis is unclear or where patients fail to respond to treatment (Box 4).

Patient education and general advice

Patients with pruritus vulvae should be given general advice on simple measures, which can help reduce itching and avoid secondary sensitization (Box 3). Patient information leaflets which summarize this advice are available from the patient.co.uk website and the British Association of Dermatologists website.

Women should be prescribed an emollient and advised to use this as a soap substitute and moisturizer. Care needs to be taken as some women may develop allergy to the preservatives in some emollients.

Topical steroids

Topical steroids are used to treat a number of vulval conditions, and patients should be given clear instructions on their use, together with written information. Very potent topical steroids (e.g. clobetasol propionate 0.05%) are used for the treatment of lichen sclerosus and lichen planus and should only be applied to the affected areas. A 30 g tube of clobetasol should last 3 months.

In order to gain symptom control, topical steroids are used daily to begin with; the frequency of application is then reduced gradually (Box 6). If symptoms flare-up when the frequency is reduced, the patient should be advised to increase application until symptoms are controlled. For patients with ongoing relapses of lichen sclerosus and lichen planus, it is safe to use clobetasol propionate as required. Most patients require 30–60 g every year.