Naevus sebaceous
What is naevus sebaceous?
Naevus sebaceous is a birthmark usually seen on the scalp or face of newborns and infants. In rare cases it can be present on other areas of the body. Naevus sebaceous can be thought of as being similar to a birthmark but made up of sebaceous cells.
What causes naevus sebaceous?
Naevus sebaceous is caused by a malformation of a small part of the skin due to minor genetic changes. It occurs randomly and in the vast majority of cases has no implications on the general health of the child.
What does naevus sebaceous look like?
Naevus sebaceous is usually noticed at birth as a skin coloured or yellow, slightly raised, waxy and pebbly change on the skin. The shape is often oval or in a straight line and can have irregular borders. The lesion often thickens as a child grows and it can develop a rough texture. On the scalp, the naevus usually remains hairless.
What other problems can occur with naevus sebaceous?
Other benign (non-cancerous) skin growths can develop on top of the naevus sebaceous as a child grows. This is thought to occur in up to 50% of cases. In less than 1% of cases a basal cell carcinoma can grow within the lesion. However these tend to occur in adults rather than in children.
In very rare cases naevus sebaceous birthmarks are very large and extensive and can be associated with Schimmelpenning syndrome or phakomatosis pigmentokeratotica. These are conditions where other abnormalities are also often present such as other birthmarks, neurological, heart, skeletal and eye problems.
How is naevus sebaceous diagnosed?
Naevus sebaceous is usually diagnosed by its typical clinical appearance. A biopsy may be needed to confirm the diagnosis in certain cases.
How is naevus sebaceous treated?
Treatment is not always necessary. Lesions can be monitored for any change by the treating dermatologist. It is also important to check for any change within the lesion and bring this to the attention of the dermatologist.
Surgical removal, if deemed necessary, is often delayed until later in childhood or adolescence. However, lesions on the face are usually removed earlier in childhood. This is especially true if lesions are close to the eyes, nose or lips where they may enlarge and cause problems with vision, breathing or eating.
This information was written by Dr Chris Jalilian