Introduction
Causes
Demographics
Clinical features
Diagnosis
Treatment
An inflammatory linear verrucous epidermal naevus (ILVEN) is a special kind of epidermal naevus. Epidermal naevi are birthmarks due to an overgrowth of the epidermis (upper layers of the skin).
The abnormality resulting in ILVEN arises from a defect in the ectoderm. This is the outer layer of the embryo that gives rise to epidermis and neural tissue. The defect causing the skin lesions may also result in disorders of other internal organs such as the brain, eyes and skeleton. This is extremely rare with ILVEN. ILVEN is highly heterogenous genetically with mosaic mutations identified in numerous genes, including NSDHL, PMVK, HRAS and CARD14. Many cases do not demonstrate a known genetic mutation.
ILVEN may be present at birth, but usually arises during the first 5 years of life and spreads over months or years. It is somewhat more common in females than in males and occurs in all races.
Like other linear epidermal naevi, ILVEN is characterised by warty lesions that tend to group together in a linear pattern. The difference is that the lesions are red, inflamed and itchy, sometimes intensely so. The surface of the lesions may look like eczema (dry, red, scratched) or like psoriasis (red and scaly).
ILVEN most often affects one leg and may extend from the buttock to the foot.
ILVEN is diagnosed by careful history and physical examination. A skin biopsy can be helpful and may show the characteristic histological features of ILVEN.
Genetic testing for a variety of mutations (see above) may help elucidate the cause and may help to direct therapy.
No curative treatment is available for ILVEN.
