Author(s): Dr Stanley Leong, Dermatology and Paediatric Registrar, Christchurch (May 2023) Reviewing dermatologist: Dr Ian Coulson (2023)
Edited by DermNet content department
A newborn presents with an unusual birthmark confined to one leg.
A linear epidermal naevus. It is an overgrowth of the epidermis and usually presents at birth or during early childhood. It is mostly flat and hyperpigmented, but there is slight thickening and scale around the ankle.
Epidermal naevi present as streaks and swirls of thickened (verrucous, hyperkeratotic, or velvety) skin along the lines of Blaschko, usually with hyperpigmentation and sometimes with adnexal involvement. They are usually unilateral, and only rarely generalised, when they may be associated with skeletal abnormalities (epidermal naevus syndrome).
In infancy, epidermal naevi can present as flat tan or brown marks, but as the child ages, they become thickened and verrucous.
Most epidermal naevi do not require treatment. Topical calcipotriol may reduce the thickness of the verrucous lesions.
Verrucous epidermal naevi can be treated with an ablative laser with good long-term aesthetic results.
