Birthmarks Slideshow: See Pictures of Birthmarks

What Is a Birthmark?

A birthmark is a colored mark on or under the skin that's present at birth or develops shortly after birth.Some birthmarks fade with time; others become more pronounced. Birthmarks may be caused by extra pigment in the skin or by blood vessels that do not grow normally. Most birthmarks are painless and harmless. In rare cases, they can cause complications or are associated with other conditions. All birthmarks should be checked by a doctor.

Salmon Patches

Salmon patches are nests of blood vessels that appear as small, pink, flat marks on the skin. They occur in 1/3 of newborn babies. Salmon patches can appear on the back of the neck (“stork bite”), between the eyes (“angel's kiss”), or on the forehead, nose, upper lip, or eyelids. Some fade as baby grows, but patches on the back of the neck usually don't go away. Salmon patches require no treatment.

Port Wine Stains

A port wine stain begins as a flat, pinkish-red mark at birth and gradually becomes darker and reddish-purple with age. Most will get bigger and thicker, too. Port wine stains are caused by dilated blood capillaries. Those on the eyelid may increase the risk of glaucoma. Port wine stains may be a sign of other disorders, but usually not. Treatment includes laser therapy, skin grafts, and masking makeup.

Mongolian Spots

Mongolian spots are flat, smooth marks that are present from birth. Frequently found on the buttocks or lower back, they're typically blue, but can also be bluish gray, bluish black, or brown. They may resemble a bruise. Mongolian spots are most common on darker-skinned babies. They usually fade by school age, but may never disappear entirely. No treatment is required.

Strawberry Hemangiomas

Hemangiomas are a collection of small, closely packed blood vessels. Strawberry hemangiomas occur on the surface of the skin, usually on the face, scalp, back, or chest. They may be red or purple; they can be flat or slightly raised, with sharp borders.

Strawberry hemangiomas usually develop a few weeks after birth. They grow rapidly through the first year before subsiding around age 9. Some slight discoloration or puckering of the skin may remain at the site. No treatment is required, but when desired, medicines and laser therapy are effective.

Cavernous Hemangiomas

Present at birth, deeper cavernous hemangiomas are just under the skin and appear as a bluish spongy mass of tissue filled with blood. If they're deep enough, the overlying skin may look normal. Cavernous hemangiomas typically appear on the head or neck. Most disappear by puberty. A combination of cavernous and strawberry hemangioma can occur.

Venous Malformation

Venous malformations are caused by abnormally formed, dilated veins. Although present at birth, they may not become apparent until later in childhood or adulthood. Venous malformations appear in 1% to 4% of babies. They are often found on the jaw, cheek, tongue, and lips. They may also appear on the limbs, trunk and internal organs, including the brain. They will continue to grow slowly, and they don't shrink with time. Treatment -- often sclerotherapy or surgery -- may be necessary for pain or impaired function.

Pigmented Nevi (Moles)

Moles occur when cells in the skin grow in a cluster instead of being spread throughout the skin. They can appear anywhere on the body, alone or in groups. Moles are usually flesh-colored, brown, or black. Moles may darken with sun exposure and during pregnancy. They tend to lose color during adulthood and may disappear in old age. Most moles are not cause for alarm. However, moles may have a slightly increased risk of becoming skin cancer. Moles should be checked by a doctor if:

• They change size or shape
• They look diffrent from other moles
• They appear after age 20

Congenital Nevi

Congenital nevi are moles that appear at birth. The skin texture may range from normal to raised, or nodular to irregular. Congenital nevi can grow anywhere on the body and vary in size --from a small 1-inch mark to a giant birthmark covering half of the body or more. Small congenital nevi occur in 1% of newborns. Most moles are not dangerous. But congenital nevi, especially large ones, should always be evaluated by a doctor since they may have an increased risk of becoming skin cancer.

Dysplastic Nevi (Atypical Moles)

Atypical moles are generally larger (one-quarter inch across or more) than ordinary moles and have irregular and indistinct borders. They may resemble cancerous moles. They may have a mix of colors including pink, red, tan and brown.These moles tend to be hereditary. Atypical moles have an increased chance of developing into melanoma skin cancer. Have a doctor evaluate all moles that look unusual, grow larger, or change in any way.

More Reading on Birthmarks & Skin Conditions

• Birthmarks and Other Skin Pigmentation Problems
• Melanoma
• Skin Tag
• Freckles
• Rosacea