Taken from www.bad.org.uk

Becker’s Naevus

What are the aims of this leaflet?

This leaflet has been written to help you understand more about a Becker’s 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 a Becker’s naevus?

‘Naevus’ is Latin for birthmark. Dr Samuel Becker, an American dermatologist, described two men with a brown patch of skin with hair-growth on the upper body in 1949. Becker’s naevus is sometimes called ‘Becker’s melanosis’ or ‘pigmented hairy epidermal naevus’.

Usually only the skin is affected in Becker’s naevus; however, sometimes the underlying tissues can be affected, for example the breast or the muscles. This has been called a Becker’s naevus syndrome.

Men are more often affected by Becker’s naevus than women, with a ratio of 5 to 1. Although most commonly people will only have one Becker’s naevus, it is possible to have more.

What causes a Becker’s naevus?

What causes a Becker’s naevus is not fully understood. Although some children are born with a Becker’s naevus, it usually appears during childhood and early teenage years. One theory is that from birth some people have a small patch of skin with the predisposition to a Becker’s naevus. Because this patch of skin is thought to be more sensitive to male hormones, it often changes during puberty.

Is a Becker’s naevus hereditary?

No. Although there are some reports of Becker’s naevus occurring in more than one family member, it does not usually run in families.

What are the symptoms of a Becker’s naevus?

Becker’s naevus does not usually cause any problems, although some people may not like the appearance. Acne or, rarely, eczema can sometimes be present in a Becker’s naevus.

What does a Becker’s naevus look like?

Initially a light brown, irregular patch of skin develops most commonly on the upper body; however, anywhere on the face, body and limbs can be affected. In puberty, this patch may enlarge, thicken and get darker. Hair can then grow on this patch and, less commonly, it develops acne.

How is a Becker’s naevus diagnosed?

The diagnosis is often made after looking at the affected skin. If unsure then a dermatologist may be asked via a referral.

Sometimes a small skin sample (known as a skin biopsy) may be taken and checked under the microscope to confirm the diagnosis.

Can a Becker’s naevus be cured?

Unfortunately, there is currently no cure for a Becker’s naevus. It will not go away on its own.

How can a Becker’s naevus be treated?

Usually a Becker’s naevus is too large to be surgically removed. Different laser systems have been used to treat both the colour and the hair. Overall the excess hair responds better to laser treatment than the colour. Please note that these laser treatments may not be available on the NHS; your medical adviser should be able to suggest a suitable clinic for laser/IPL treatment.

If there is acne or eczema within the Becker’s naevus, treatment of these skin conditions can be helpful.

Self care (What can I do?)

The hair on a Becker’s naevus can be safely removed by shaving, waxing, threading or using epilation creams, for example; these will not increase the hair-growth.

Where can I get more information about a Becker’s naevus?

Web links to detailed leaflets:


For details of source materials used please contact the Clinical Standards Unit (clinicalstandards@bad.org.uk).

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: its contents, however, may occasionally differ from the advice given to you by your doctor. This leaflet has been assessed for readability by the British Association of Dermatologists’ Patient Information Lay Review Panel