Linear verrucous epidermal nevus

A type of skin lesion

Linear verrucous epidermal nevus (LVEN) is a type of epidermal nevus characterized by a linear arrangement of verrucous skin lesions. These lesions are typically present at birth or develop in early childhood and are caused by a genetic mosaicism.

Presentation

Linear verrucous epidermal nevus on the arm

Linear verrucous epidermal nevus presents as a series of hyperkeratotic and verrucous papules that coalesce into linear plaques. These lesions follow the lines of Blaschko's lines, which are patterns of skin cell development. The lesions are often hyperpigmented and can vary in color from light brown to dark brown or black.

Pathophysiology

LVEN is caused by a postzygotic mutation leading to genetic mosaicism. This results in a localized area of skin cells that proliferate abnormally, forming the characteristic lesions. The exact genetic mutations involved can vary, but they often affect genes related to skin cell growth and differentiation.

Diagnosis

Diagnosis of linear verrucous epidermal nevus is primarily clinical, based on the appearance and distribution of the lesions. A skin biopsy may be performed to confirm the diagnosis and rule out other conditions. Histologically, the lesions show acanthosis, hyperkeratosis, and papillomatosis.

Management

Management of LVEN is often conservative, as the lesions are benign. However, treatment may be sought for cosmetic reasons or if the lesions become symptomatic. Options include:

• Topical treatments such as keratolytics or retinoids
• Cryotherapy
• Laser therapy
• Surgical excision

Prognosis

The prognosis for individuals with linear verrucous epidermal nevus is generally good, as the condition is benign. However, there is a small risk of malignant transformation in long-standing lesions, so regular monitoring is recommended.

Related pages

• Epidermal nevus
• Blaschko's lines
• Genetic mosaicism