Vulvar Contact Dermatitis

Vulvar contact dermatitis is vulval skin inflammation caused by contact with an irritant or an allergen, and includes both irritant and allergic forms. It is common in women of all ages and is often chronic.

• The thin, moist, occluded vulval skin absorbs substances readily.
• Many women have more than one cause, and prior treatment creams are common culprits.
• Chronic scratching leads to lichen simplex chronicus.

Itching, burning and soreness of the vulva, with red, swollen, weeping or scaly skin on the labia majora, labia minora and perineum.

• Chronic cases have thickened, leathery, whitened skin with excoriation.
• Dyspareunia and sleep loss from itch.
• Differential diagnosis: lichen sclerosus, lichen planus, lichen simplex chronicus, psoriasis, candidiasis, tinea cruris, extramammary Paget disease, vulval intraepithelial neoplasia.
• Complications: secondary infection, lichenification, scarring if misdiagnosed lichen sclerosus, chronic pain.

Diagnosis is clinical, by history of exposure, examination and exclusion of other vulval disease.

• History of all products used on or near the vulva, including medicated creams, soaps, pads and wipes.
• Examination of the vulva, perianal area, groin and other skin sites.
• Vaginal swab and potassium hydroxide preparation to exclude candidiasis; skin scrapings for tinea.
• Random blood glucose.
• Biopsy for lesions lasting beyond 6 weeks of treatment, or white, red, ulcerated or pigmented areas.
• Patch testing when allergy is suspected.

Remove triggers, restore the skin barrier, and use a topical corticosteroid for a limited period.

• Supportive: stop all potential triggers; wash with water or a soap substitute; avoid wipes, douches, perfumed products; emollient (petroleum jelly or emulsifying ointment) 2 to 3 times daily and as a barrier; cotton underwear; short fingernails to limit scratching.
• Pharmacological: betamethasone valerate 0.1 percent cream applied thinly once or twice daily for 7 to 14 days, then reduce to alternate days for 1 to 2 weeks, then stop. Use hydrocortisone 1 percent cream for mild disease or children. Night itch: chlorphenamine 4 mg oral at night (maximum 24 mg in 24 hours) or cetirizine 10 mg oral at night. Secondary candidiasis: clotrimazole 1 percent cream twice daily for 2 weeks. Secondary bacterial infection: flucloxacillin 500 mg oral 6-hourly for 5 to 7 days (child 12.5 to 25 mg/kg 6-hourly, maximum 500 mg per dose). Do not use potent steroids beyond 4 weeks without review.
• Procedures: punch biopsy under local anaesthesia (1 percent lignocaine, maximum 3 mg/kg) for atypical or persistent lesions.
• Special groups: in children use hydrocortisone 1 percent for up to 7 days and avoid potent steroids; in diabetes control glucose to prevent recurrent candidiasis; in elderly women check for incontinence and lichen sclerosus.
• Red flags: white sclerotic plaques, ulcers, fixed or pigmented lesions, bleeding, no response in 6 weeks.
• Follow-up: review at 2 to 4 weeks; refer for patch testing or dermatology if the rash persists or recurs.