Lasers have been used to treat sebaceous naevus with varying success

sebaceous naevus
A sebaceous naevus is an uncommon type of birthmark. Present at birth, it is most often found on the scalp, but sebaceous naevi may also arise on the face, neck or forehead. It consists of overgrown epidermis (upper layers of the skin), sebaceous glands, hair follicles, apocrine glands and connective tissue. It is a type of epidermal naevus and is classified as a benign hair follicle tumour. A sebaceous naevus is also called an organoid naevus because it may include components of the entire skin.
presents as a solitary, smooth, yellow-orange hairless patch, often oval or linear in shape.
due to a mosaic genetic abnormality, i.e. a line of cells with a genetic error
A biopsywill show a hairless lesion with immature hair follicles and sebaceous glands.
treatment
A sebaceous naevus should be monitored. If a lump or sore appears within a sebaceous naevus, arrange for it to be reviewed by a dermatologist. It may require a biopsy or the whole sebaceous naevus may be excised (cut out).

Full skin thickness excision may also be arranged for cosmetic reasons but a scar is inevitable.

Lasers have been used to treat sebaceous naevus with varying success.