INTRODUCTION

Vulvar dermatitis (also called vulvar eczema) is the most common vulvar dermatosis in women. One-third to one-half of women's vulvar complaints stem from this problem [1-3]. It can develop in isolation or may occur as part of dermatitis in other areas of the body.

Women with vulvar dermatitis experience chronic irritation and/or pruritus, which causes them to persistently rub and scratch the vulva. These activities lead to histological changes in the dermis, termed squamous hyperplasia or lichen simplex chronicus.

ENDOGENOUS VERSUS EXOGENOUS DERMATITIS

The two types of vulvar dermatitis are endogenous and exogenous.

• Endogenous vulvar dermatitis is the term used to describe atopic dermatitis of the vulva. Atopic dermatitis has a familial predisposition, often begins in childhood, and is characterized by pruritus. Although some experts feel that vulvar involvement is unusual, even when there is severe and widespread atopic dermatitis elsewhere (picture 1), others believe it is more prevalent than previously acknowledged [4,5]. In women with atopic dermatitis at nongenital periorificial sites, the occurrence of erythema in the labial folds, the perianal region, and in the skin between the buttocks probably represents endogenous vulvar dermatitis. (See "Epidemiology, clinical manifestations, and diagnosis of atopic dermatitis (eczema)".)
• Exogenous vulvar dermatitis results from external factors, and is also called contact dermatitis (picture 2A-B). In allergic contact dermatitis (20 percent of cases), the trigger (allergen) induces an immune response, while in irritant contact dermatitis (80 percent of cases), the trigger (irritant) itself directly damages the skin. Although exposure to irritants may have been the initial cause of the dermatitis, secondary sensitization to allergens can also occur.

The most common agents that cause irritant or allergic contact dermatitis of the vulva are listed in the table (table 1). Active and inert constituents of topical medications are a very common etiology of allergic dermatitis of the vulva in women with persistent vulvar symptoms [6]. Sensitivity to latex or proteins in seminal plasma are infrequent etiologies [7]. (See "Overview of dermatitis", section on 'Contact dermatitis'.)