Sebaceous naevus - BAD Patient Hub

What are the aims of this leaflet?

This leaflet has been written to help you understand more about sebaceous naevus. It tells you what it is, what causes it, what can be done about it, and where you can find out more about it.

What is sebaceous naevus?

Sebaceous naevus is a rare type of birthmark. It also known as nevus sebaceous, nevus sebaceous of Jadassohn, or organoid naevus. It is usually seen as soon as the baby is born. However, in some cases it is not noticed until later. It affects around 0.3% (3 in 1,000) of new-borns in the UK. People of all skin types are equally affected.

Sebaceous naevus is harmless and non-infectious. It is an overgrowth of sebaceous (oil) glands, hair follicles, sweat glands and other skin parts.

What causes sebaceous naevus?

Sebaceous naevus is thought to be due to minor genetic changes in a small area of skin. This causes some cells in the skin to overgrow.

Is sebaceous naevus hereditary?

It is not hereditary. The genetic change is only within the sebaceous naevus, not the rest of the body.

What does sebaceous naevus look like and feel like?

In infants or young children, a sebaceous naevus looks like a smooth, yellow-orange, hairless skin patch. It is usually oval or forms a line. It most often appears on the scalp, or in areas near the ears, face, or neck.

Sebaceous naevi can vary in size from 1 cm to several centimetres. In early childhood, a sebaceous naevus usually remains unchanged. However, as a person reaches puberty, it may thicken and appear bumpier, warty, or scaly.

How is sebaceous naevus diagnosed?

Most sebaceous naevi are easy to recognise in childhood or adolescence by their distinct appearance. If it changes in an unusual way, a doctor may suggest a biopsy. This helps rule out rare changes, such as cancerous growths, that could appear especially later in life.

Can sebaceous naevus be cured?

Sebaceous naevus can be effectively treated through surgical removal, although this is not usually required, and surgical excision may leave a significant scar.

Are there any reasons to be concerned?

Sometimes, particularly after puberty, new growths can occur within this birthmark. Most are benign (harmless) but rarely, there can be a cancerous growth. Basal cell carcinoma, which is the most frequent cancerous growth, affects less than 1% of untreated sebaceous naevi. These carcinomas are typically completely cured with surgical removal.

Very big sebaceous naevi can be associated with problems with the eyes, brain or skeleton but this is very rare.

How can sebaceous naevus be treated?

In most cases, monitoring of the naevus is enough. This is because the risk of cancers forming within them is extremely low. You should contact your healthcare professional if you are concerned there is a new lump or sore within the naevus.

Surgical removal or a biopsy is only recommended if there is concern about a new growth within the birthmark. However, some people choose to have their sebaceous naevus removed for cosmetic reasons.

The decision to excise the lesion should be made on an individual basis with your doctor. Factors to consider include your age, location and size of the lesion, as well as your concerns about cosmetic appearance and risk of malignancy. It is important to note that any surgical procedure may leave an undesirable scar.

Self-care (What can I do?)

It is important to monitor the birthmark for any changes and speak to your GP or Dermatologist if you have any concerns.

Where can I get more information about sebaceous naevus?

Patient support groups providing information:

www.changingfaces.org.uk/services-support/

Web links to detailed leaflets:

www.dermnetnz.org/topics/sebaceous-naevus

www.patient.info/doctor/sebaceous-naevus

Please note that the British Association of Dermatologists (BAD) provides web links to additional resources to help people access a range of information about their treatment or skin condition. The views expressed in these external resources may not be shared by the BAD or its members. The BAD has no control of and does not endorse the content of external links.

This leaflet aims to provide accurate information about the subject and is a consensus of the views held by representatives of the British Association of Dermatologists: individual patient circumstances may differ, which might alter both the advice and course of therapy given to you by your doctor.

This leaflet has been assessed for readability by the British Association of Dermatologists’ Patient Information Lay Review Panel