Dermatological disorders

The vulval skin is part of the body integument and is therefore subject to all the disorders that can affect the skin elsewhere, although their appearance may differ from that on other parts of the body; for example, lichen planus, psoriasis or pemphigus, as well as those conditions that affect mucous membranes. Lichen simplex, lichen sclerosus and lichen planus merit special attention because they occur with some frequency in the skin of the vulva. The first two disorders were previously termed ‘vulval dystrophies’, a form of nomenclature now obsolete.

LICHEN SIMPLEX

Previously classed as ‘hyperplastic dystrophy’, lichen simplex appears as circumscribed areas of ill-defined, thickened red, white or brown coloured skin, usually on the labia majora. Histologically, the squamous epithelium is thickened and shows acanthosis, elongation of the rete pegs, parakeratosis and hyperkeratosis with a non-specific chronic inflammatory cell infiltrate of the dermis. Figure 1.1 shows these epithelial changes in the absence of an inflammatory cell infiltrate of the dermis: such epithelial changes alone are simply classed as ‘squamous hyperplasia’ or ‘squamous epithelial hyperplasia’. Lichen simplex alone is not associated with any increased risk of vulval carcinoma. The term lichenification is applied to similar epidermal changes superimposed on an underlying dermatological disorder such as eczema and may clinically mask the underlying condition.

LICHEN SCLEROSUS

Lichen sclerosus can occur in any part of the skin: (about 11% of women have extragenital lesions) but it has a particular predilection for the genital area. The skin lesions are papular and occur singly or in confluent patches.