Rare Endocrinology News

Disease Profile

Becker’s nevus

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Becker melanosis; Becker nevus; Becker naevus


Skin Diseases


Becker's nevus is a non-cancerous, large, brown birthmark occurring mostly in males. It can be present at birth, but is usually first noticed around puberty. It typically occurs on one shoulder and upper trunk but occasionally occurs elsewhere on the body. A Becker's nevus often becomes darker, and excessive hair growth (hypertrichosis) and acne may develop within the nevus.[1][2]

Becker's nevus is due to overgrowth of the epidermis (upper layer of the skin), pigment cells (melanocytes) and hair follicles.[2] The specific underlying cause is unknown.[3] Because it often forms around puberty in males and is sometimes associated with acne and hair growth, its development may be triggered by androgens (male sex hormones such as testosterone).[1][3]

Treatment is primarily for cosmetic reasons (hyperpigmentation or hair growth) and may include Ruby laser treatment or laser-assisted hair removal.[3][1]

In very rare cases, Becker's nevus is associated with other skin features; muscular or skeletal features; or underdevelopment (hypoplasia) of the breast. When this occurs, the condition is known as Becker's nevus syndrome.[4]


A Becker's nevus typically begins to develop around puberty on the shoulder or upper trunk, although it may develop on other areas of the body.[2] It is sometimes present from birth.[1] Pigmentation (darkening of skin color) may be subtle at first, but the nevus often darkens after puberty and expands.[3] The resulting birthmark is usually large, brown, and on one side of the body. The nevus may grow more hair than the surrounding skin. In some cases, acne develops within the nevus.[2]


Becker's nevus typically does not require treatment except for cosmetic reasons primarily excessive hair growth (hypertrichosis) and hyperpigmentation.[3]

Treatment has always been challenging, often using lasers with mixed results.[5] Q-switched ruby laser has been used with variable success in the treatment of both the hypertrichosis and hyperpigmentation.[3] Hypertrichosis may also be improved by laser-assisted hair removal or by electrolysis.[1][2] Hyperpigmentation may be lessened with Q-switched Nd:YAG laser or fractional resurfacing, although responses are variable and recurrence rates are high.[1] Acne that develops within the nevus can be treated with standard acne therapies.[2]

People with Becker's nevi should be examined for associated soft tissue and bony abnormalities.[1]

More detailed information about the treatment of Becker's nevus is available here on Medscape Reference's website. You may need to register to view this, but registration is free.


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Learn more

    These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

    Where to Start

    • DermNet NZ is an online resource about skin diseases developed by the New Zealand Dermatological Society Incorporated. DermNet NZ provides information about this condition.

      In-Depth Information

      • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
      • PubMed is a searchable database of medical literature and lists journal articles that discuss Becker's nevus. Click on the link to view a sample search on this topic.


        1. Julie V Schaffer, Jean L Bolognia. Benign pigmented skin lesions other than melanocytic nevi (moles). UpToDate. Waltham, MA: UpToDate; August, 2016;
        2. Vanessa Ngan. Becker naevus. DermNet NZ. 2003; https://www.dermnet.org.nz/lesions/beckers-naevus.html.
        3. Jason K. Rivers. Becker Melanosis. Medscape Reference. June 3, 2016; https://emedicine.medscape.com/article/1068257-overview.
        4. Wilson H. Y. Lo. Becker Nevus Syndrome. OMIM. May 4, 2000; https://omim.org/entry/604919.
        5. Momen S, Mallipeddi R, Al-Niaimi F. The use of lasers in Becker's naevus: An evidence-based review. J Cosmet Laser Ther. August, 2016; 18(4):188-192.

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