Birthmarks - pigmented

Alternative names
Nevus sebaceous; Hairy nevus; Nevi; Mole; Cafe-au-lait spots; Congenital nevus

A birthmark is skin marking present at birth that ranges in color from brown or black to bluish or blue-gray. Birthmarks include cafe-au-lait spots, moles, and mongolian spots. (See also birthmarks - red.)

Causes, incidence, and risk factors
Cafe-au-lait spots are a light tan spot, the color of coffee with milk. They may be a normal type of birthmark. The presence of several cafe-au-lait spots larger than a quarter may occur in neurofibromatosis (a genetic disorder that causes abnormal cell growth of nerve tissues).

Moles are small clusters of pigmented skin cells. Nearly everyone has moles, which usually appear after birth.

Congenital nevi (moles present at birth) have an increased risk of becoming skin cancer (malignant melanoma). This is especially true if the nevus covers a large area of the body (larger than a fist). All congenital nevi should be examined by a health care provider and any change in the birthmark should be reported. Watch for changes in the size or color, or the appearance of sudden ulceration, bleeding, or itching in the birthmark.

A mongolian spot (also called a mongolian blue spot) is usually bluish or bruised-looking. It usually appears over the lower back or buttocks, sometimes in other areas including the trunk or arms. These are more commonly seen in darker-skinned populations and may persist for months or years but do not become cancer or develop other symptoms.


  • skin, abnormally dark or light       o brown, black, bluish, or blue-gray  
  • skin lumps  
  • skin lesion  
  • discolorations, lumps, or lesions may       o be variable in size       o contain hair       o be smooth, flat, raised, or wrinkled

Signs and tests
Diagnosis is usually made on the basis of the appearance of the skin area. A biopsy may be performed on a removed mole to look for cancerous changes.

Treatment varies depending on the type of birthmark and associated conditions. Usually no treatment is required for the birthmark itself.

Large or prominent nevi that affect the appearance and self-esteem may be covered with special cosmetics.

Moles may be removed surgically if they affect the appearance or if they have an increased cancer risk. Be sure to discuss your options with your doctor to decide how and when to remove any moles.

Support Groups
The Nevus Outreach ( provides support for patients with large birthmarks.

Expectations (prognosis)

Congenital nevi have an increased cancer risk and should be examined.


  • skin cancer  
  • psychological effects if the birthmark is prominent

Calling your health care provider
All birthmarks should be examined by a health care provider to determine the prognosis (probable outcome), course of action, and possible complications.

Call for an appointment with your health care provider if any change occurs in color, size, or texture of a nevus or other skin lesion.

Call for an appointment with your health care provider if there is development of pain, inflammation, ulceration, bleeding or itching of a congenital nevus or other skin lesion, or if questions or concerns develop.

There is no known way to prevent birthmarks. It may be advisable for a person with birthmarks to use a good quality sunscreen when outdoors (to prevent complications).

Johns Hopkins patient information

Last revised: December 3, 2012
by Gevorg A. Poghosian, Ph.D.

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.