Sebaceous naevus
Introduction
A sebaceous naevus (suh-bay-shuhs neh·vuhs), also known as a sebaceous mole, is an uncommontype of birthmark. It is made up of an oil secreting skin cell called a sebaceous gland. Sebaceous moles are often on the heads and faces of new-born babies. Sometimes, they can be on other areas of the body. The majority of children born with this type of birthmark have no underlying medical issue and are otherwise healthy and well.
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Waxy yellow birthmark on the scalp of a child
Who gets it?
Any child can be born with a sebaceous naevus. It is equally present in boys and girls and can affect people of all races.
What causes it?
A sebaceous mole is a birthmark which is thought to be due to a genetic abnormality. As a baby develops inside a mother’s womb, there is a layer of tissue that forms the top layer of the skin. In certain areas, the top layer of skin becomes thicker which creates a thick patch of oil secreting glands. This becomes a sebaceous naevus once the baby is born. This condition is not caused by anything that the mother did or did not do during the pregnancy. It is not an infection or cancer.
If you have a family member with a sebaceous naevus, you are more likely to have one.
What does it look and feel like?
Looks like…
In babies and children, a sebaceous naevus usually appears as a raised, smooth, hairless patch of skin.
It can be orange, yellow or pink in colour.
The area will often change during puberty, becoming more raised and bumpy. At this time, it can also become lighter or darker than your skin colour.
Feels like…
Raised
Flat or bumpy
Painless
What tests might be needed?
Sebaceous naevus has an obvious appearance and a dermatologist or doctor can usually diagnose it by looking at your child's birthmark. Often no tests are needed but occasionally your doctor might want to perform a skin biopsy, where a small sample of your child's skin is removed for testing.
What treatments are available?
A sebaceous mole does not go away on its own and should be monitored for any changes. If a lump or sore appears within the sebaceous naevus, arrange for your child to be reviewed by a dermatologist.
What can I do?
Be careful when brushing, combing or cutting your child's hair.
Have your child's doctor monitor the birthmark over time.
Medical therapies
Surgical removal: In most cases, no treatment is required as it can be hidden in the scalp with hair. However, in some situations these birthmarks can be cut out to improve the appearance. This is usually performed by a dermatologist or plastic surgeon. This decision is best left until your child is able to make that choice for themselves and is able to tolerate the procedure.
What happens after treatment?
If you and your child choose to have surgical removal, the sebaceous mole will be gone and will not grow back. Your child will have a scar where it was removed.
If you and your child choose not to remove the sebaceous mole, it will either stay the same or change over time. Rarely, other skin problems can occur within a sebaceous naevus so it is important to have a review with a dermatologist if you notice changes to your child's birthmark.
What support is available?
Your general practitioner or a dermatologist can provide advice regarding treatment and surveillance.
Authors/Reviewers:
Author: Dr Claudia Hadlow
Paediatric Reviewer: Dr Mayuri Sivagnanam
Editor in Chief: Dr Tevi Wain
