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VULVA

The vulva may be affected by a variety of dermatoses, such as psoriasis, lichen planus, some immunobullous disorders, and eczemas (lichen simplex, contact dermatitis, seborrhoeic dermatitis, and others). Hidradenitis suppurativa and Crohn disease may present with vulval skin lesions. Infections and infestations that affect the vulva include viral warts, candidiasis, threadworms, scabies, and pediculosis pubis.

Lichen sclerosus, vulvar

Etiology and pathogenesis

The etiology is uncertain and may be multifactorial. There are well-documented associations with a variety of autoimmune and other conditions (discussed in more detail in Ch.22). A series of patients with vulvar lichen sclerosus (LS) and lichenoid oral lesions has been reported.

    Vulvar LS tends to affect either prepubescent girls or perimenopausal women. It may rarely be familial in children. In one study of lesions in children, 50% resolved within 7 years. The adult form may be more persistent and problematic. Trauma may induce LS via koebnerization.

Clinical

White, atrophic, crinkled, shiny areas with follicular plugging develop symmetrically about the vagina and rectum in vulvar LS (Fig.20.62). Pruritus, burning pain, dyspareunia, dysuria, vaginal discharge, anal or genital bleeding, labial stenosis or fusion (Figs 20.63 and 20.64), constipation (especially in children), erosion, contraction, and SCC may occur.

Differential diagnosis

The only likely differentials are as follows.

    Squamous cell carcinoma within LS may also need to be excluded if there are thickened or chronically eroded areas. Any suspicious areas should be biopsied.

Figure 20.68 Allergic contact dermatitis due to a fragrance in an antipruritic cream. The white areas are macerated keratin, not leukoplakia.

Figure 20.69 Tinea cruris.

Figure 20.70 Primary herpes genitalis. (Courtesy of Michael O. Murphy, M.D.)

Figure 20.71 Squamous cell carcinoma of the vulva.

Figure 20.72 Lymphedema. Kidney transplant patient with leg scrotal edema. Note: the papillomatous surface is similar to that seen in elephantiasis.

Treatment

Clobetasol propionate (twice daily for 1 month, every day for 2 months, then twice a week) is dramatically effective in most cases. Within a week, the pruritus is greatly reduced, but the clobetasol should be continued to reduce progressive scarring. Less potent topical corticosteroids have also been used. The wearing of underwear helps prevent exposure of the thighs to the effects of the steroid, as the skin of the inner thigh by comparison to the vulval skin is more prone to the atrophy that steroids can produce. Petrolatum alone is beneficial.

Figure 20.73 A red scrotum may be caused by a variety of conditions. See text below.

    Follow-up may vary according to the healthcare system and whether the patient is also under the care of a primary care physician. Those with troublesome symptoms or erosive disease require closer monitoring, as SCC will be more difficult to detect than in those with quiescent disease.

PRACTICE POINTS

Lichen simplex chronicus

Etiology and pathogenesis

Lichen simplex chronicus (LSC) is due to chronic scratching. The patient usually presents with intractable itching that has been present for months to years. Often the scratching is worse at night. Although the problem self-perpetuates, it is important to realize that there may be initial or ongoing reasons for itch (see under Differential diagnosis ). Some have used the term hyperplastic dystrophy in the past, or more recently squamous cell hyperplasia.

Figure 20.74 Perianal dermatitis.

Clinical

Lichenied areas in the vulva that the patient constantly scratches are characteristic (Fig.20.66). It is analogous to scrotal LSC in men (Fig.20.67). Examination of mild cases may show only erythema. Moderately severe cases usually have some sort of lichenification. Severe disease is marked by erythema, lichenification, and erosions from vigorous scratching. In darker-skinned patients, postinflammatory hypopigmentation may occur. Lichenification in the moist folds appears white secondary to the hydration of the hyperkeratotic skin.

Differential diagnosis

Most of the following either may initiate LSC or may be in the differential diagnosis. Biopsy may be required to exclude some of these, especially if the patient does not respond well to the therapy outlined here. Patch testing or other investigations may also be appropriate. Differential diagnoses and initiating factors include the following.

Treatment

Patients should be told clearly but with sensitivity that, unless they stop scratching, the problem will persist. Any trigger factors (e.g. heat, excessive bathing, scrubbing, over-the-counter preparations, and candidal infection) should be eliminated. A medium-potency topical steroid (e.g. triamcinolone 0.1% cream) should be prescribed initially for most cases, although in severe cases a high-potency topical steroid (e.g. clobetasol) for a very limited period of time may be needed. Sometimes, when there is chronic lichenification, it is only by aggressive treatment of ongoing itch and subsequent self-inflicted damage that a primary cause can be identified. The risk of striae from topical steroids should be discussed. The patient should be instructed to wear underwear to prevent the steroid from coming in contact with the thighs. As the itch remits over 2–4 weeks, the patient should be switched over to an emolliating cream as tolerated. Some patients require nighttime sedation to stop scratching. One should start initially with an antihistamine (e.g. hydroxyzine, 25 mg at supper time or before sleeping). If this fails, doxepin or amitriptyline may be tried. In some patients, emotional and psychologic factors play a key role. Techniques to reduce stress and in some cases anxiolytics may be helpful.

Allergic contact dermatitis

Allergic contact dermatitis is discussed in detail in Chapter 6. Allergens of importance on vulval skin include latex (condoms), nickel (possibly by transfer from the hands), and a variety of perfumes and preservatives. The latter two groups of chemicals may be present in soaps, in toilet tissue and wet wipes, and in medicaments. Self-medication of pruritus vulvae may therefore inadvertently increase the problem. Allergic contact dermatitis to a topically applied cream is shown in Figure 20.68.

Tinea cruris

A dermatophyte infection is uncommon in the groin of a woman but does occur (see Ch.26 and Fig. 20.69).

Herpes simplex

See Chapter 25 and Figure 20.70.

Skin cancers

Rarely, skin cancers may arise in vulval skin (Fig. 20.71), usually in older women. SCC is most frequent, and may arise on a background of preexisting LS. Basal cell carcinomas, and rarely melanoma, may also occur. The genital skin in either sex may be affected by extramammary Paget disease (see Ch.33), which may clinically resemble eczema. A variety of benign skin appendage tumors also occur on vulval skin.

Disorders of the vulval introitus

Conditions affecting the mucosal surface of the vulva may be treated primarily by gynecologists, dermatologists, or both together as a multidisciplinary clinic. Disorders at this site include plasma cell vulvitis (the female equivalent of Zoon plasma cell balanitis), vulvar vestibulitis, and vulvodynia (or ‘burning vulva' syndrome). The last may be caused by infections such as candidiasis, eczematous processes, LS or lichen planus, or vestibulitis; psychologic causes are also commonly implicated, and antidepressant medications may be useful if no specific underlying skin disorder can be demonstrated.

White/Cox: Diseases of the Skin, 2ed.(c) 2006, Elsevier Inc. All rights reserved.