Vulvar lichen simplex chronicus (VLSC), formerly referred to as vulvar squamous epithelial hyperplasia or hyperplastic dystrophy, can occur at any age and is most commonly seen in women of reproductive age. The condition is characterized by localized thickening of the skin, hypopigmented or hyperpigmented lichenified plaques, primarily caused by chronic stimuli such as scratching or friction.
Etiology
The exact cause is unknown. VLSC can be classified into primary and secondary types. Primary VLSC is often associated with neuropsychiatric factors, dysfunction of cutaneous nerves, allergic conditions, or chronic friction or scratching due to local environmental factors. Secondary VLSC may develop as a result of underlying conditions such as vulvar lichen sclerosus (VLS), vulvar lichen planus (VLP), or other vulvar disorders.
Pathology
On gross examination, the affected skin may appear as red or white patches or exhibit a lichenified texture. Histologically, the findings lack specificity. Common features include hyperkeratosis and parakeratosis of squamous epithelial surface cells, acanthosis, and fibrosis in the superficial dermis accompanied by varying degrees of inflammatory cell infiltration. The epithelial cells display orderly arrangement, preserved polarity, and normal nuclear size, shape, and staining characteristics.
Clinical Features
Symptoms
Severe pruritus is the main complaint, often intolerable. While scratching and rubbing may temporarily relieve discomfort, they disrupt the skin's barrier function, leading to epidermal thickening and chronic damage, perpetuating an itch-scratch cycle.
Signs
Lesions typically involve the labia majora, the interlabial sulci, the clitoral hood, and the posterior commissure. The lesions may be solitary, multiple, or bilaterally symmetrical. Early-stage disease is marked by dark red or pink patches, which may progress to white lesions as the condition worsens. In later stages, the skin becomes thickened with hyperpigmentation, exaggerated skin markings, and a lichenified appearance, often accompanied by scratch marks, fissures, and ulcers.
Diagnosis
Clinical Diagnosis
Diagnosis is based on patient history, symptoms, and a comprehensive physical examination. A biopsy is not routinely indicated, especially in younger patients, unless specific clinical concerns are present.
Histopathological Diagnosis
A definitive diagnosis depends on histopathological examination. Biopsy specimens should be taken from areas of hypopigmentation, rough texture, raised lesions, induration, fissures, or ulcers. Non-specific histological findings do not exclude the diagnosis of VLSC.
Differential Diagnosis
VLSC should be differentiated from vitiligo, albinism, nonspecific vulvitis, vulvar squamous intraepithelial lesions, and malignancies.
Treatment
The goals of treatment include eliminating triggering factors, addressing primary diseases, reducing inflammation, disrupting the itch-scratch cycle, and restoring vulvar function. Proper management can result in complete resolution in some cases, although recurrence is common.
General Care
Avoiding local irritants is essential. Recommendations include bland sitz baths with non-irritating anti-inflammatory solutions, a non-spicy diet, and, when necessary, anti-inflammatory, antihistamine, or sedative therapies. Psychological therapies may also be helpful.
Pharmacological Treatment
The treatment strategy is similar to that for VLS. Moderate- to high-potency topical corticosteroids (TCs) are used to control pruritus. After symptom resolution, low-potency TCs are employed for maintenance therapy. Patients intolerant to corticosteroids may use 0.1% tacrolimus or 1% pimecrolimus. While symptoms may improve significantly, thickened skin may require a prolonged period to show noticeable improvement.
Physical Therapy
For severe symptoms or cases unresponsive to medical treatment, physical therapy may be used to remove abnormal epithelial tissue and damage dermal nerve endings, thereby disrupting the itch-scratch cycle. Common methods include fractional laser therapy and focused ultrasound.
Surgical Treatment
Malignant transformation and scarring are rare in VLSC. Surgical treatments may alter appearance and local functions and carry a risk of recurrence, making them generally undesirable. Surgery is considered only in cases where repeated pharmacologic and physical therapies fail or there is atypia or suspicion of malignancy.