Birthmarks are colored skin spots or spots with no skin color that are present at birth or develop shortly after birth. Birthmarks can be many different colors, including brown, tan, black, pale blue, pink, red, or purple. Some birthmarks are only on the surface of the skin. Others extend into the tissues under the skin or raise above the surface of the skin.

Most birthmarks need no treatment. They often fade as a child grows older. However, some birthmarks may need treatment because of their location. For example, a raised birthmark near a child's eye may interfere with his or her ability to see. Rarely, birthmarks are associated with other conditions, such as growths on the liver, lungs, stomach, or intestines.

Some birthmarks stay the same as the child grows older, while some birthmarks fade in time. Others grow quickly over a short period of time. Although most are harmless, it is important to point out all birthmarks or any changes in your baby's skin to a health professional at the time of a visit.

The cause of many birthmarks is unknown. Most birthmarks are not inherited. Many folktales and myths exist about the causes of birthmarks, but none of these folktales and myths explain the true causes of birthmarks.

Common birthmarks fall into the following categories.

Pigmentation type birthmarks

• Congenital nevi. Mole is a non-specific term for nevus. A nevus is a pigmented skin spot that is present from birth. Some large nevi may have cancerous changes later in life.
• Cafe-au-lait spots. Cafe-au-lait (coffee with cream) spots are caused by too much color (pigment) in the skin. A single cafe-au-lait spot usually is not a sign of a health problem. However, 5 or more spots that are larger than 0.25 in. (6.35 mm) in diameter or ones that occur along with freckles in the armpit may suggest other health problems. Most cafe-au-lait spots do not go away, may increase in number, and do not require treatment.
• Mongolian spots. Mongolian spots are flat, slate blue-gray patches that usually are found across the lower back and buttocks. They tend to occur in children of Asian, Southern European, Hispanic, Pacific Island, or African descent. Mongolian spots usually disappear by school age without treatment.

Macular stains (salmon patches)

Salmon patches are very thin, light pink, flat patches of discoloration. They often develop along a baby's hairline on the back (nape) of the neck (“stork bites”) on the baby's upper eyelids or upper lip, or between the eyebrows (“angel kisses”). These types of birthmarks are more noticeable when a baby is crying or when he is hot or cold. Most salmon patches on the eyelids fade without treatment within the first year of life. However, most salmon patches on the nape of the neck stay for life.

Vascular malformations

Vascular malformations are caused by abnormal development of blood vessels. They almost always are present at birth. However, they also can develop during the baby's first year of life. Sometimes, even though they were present at birth, vascular malformations become apparent later in life. For example, they may become apparent only during periods of time when the person's hormones are changing, such as during puberty or when a woman is pregnant. The most common types of vascular malformations are:

• Port-wine stains. Port-wine stains are flat birthmarks that are pink-red at birth and darken to a red-purple color by several years of age. They generally are found on the face but can occur anywhere on the body. Port-wine stains may be associated with eye and/or brain problems if located on the face above or around the eye. They do not fade or go away. Most port-wine stains darken, thicken, and form vascular bumps (blebs) in adulthood. However, they can be treated with laser therapy or surgery.
• Venous plexi. Venous plexi are thin, light blue patches of discoloration. They may be flat or raised.

Hemangiomas

Hemangiomas are caused by many tiny blood vessels bunched together. There are 3 basic types of hemangiomas:

• Superficial or capillary hemangiomas (often called strawberry hemangiomas). These are thick, raised areas that are soft, purplish-red, smooth, or slightly bumpy. They may have circular borders or irregular borders. They may be present at birth or develop up to a few months after birth. Superficial hemangiomas most often develop on the face, scalp, back, or chest. However, they can occur anywhere on the body. Superficial hemangiomas may stay the same size or they may grow rapidly over a period of a few months.
• Deep hemangiomas (cavernous). Deep hemangiomas are thick, deep, raised areas that often are purple-blue in color. They may feel like spongy tissue filled with fluid. Deep hemangiomas often fade as a child gets older. However, because they are deeper, they may not shrink totally, or they may leave a fine dimpling scar after they fade. A child with a deep hemangioma may need surgery to remove it or its scar.
• Compound or mixed hemangiomas. These are a combination of superficial (on the surface) and deep hemangiomas.

Hemangiomas may not be present at birth. The baby may be several weeks old before they appear. Hemangiomas are the most common growths (tumors) in babies; they occur in about 1% to 2% of newborns.¹ As many as 10% to 12% of babies have them by the time they are 1 year old.¹ Most hemangiomas develop around the head and neck, and most babies have only one hemangioma; however, they may have more than one. On rare occasions, hemangiomas may grow on internal organs, such as the stomach, intestines, liver, or kidneys. These may cause other problems, depending on the organ they grow on.

Hemangiomas that are present at birth may shrink quickly (involute) immediately after birth. Most other hemangiomas go through a stage of rapid growth (proliferation), then a stage of shrinking and fading (involution), which may be much more gradual. Some disappear completely by 18 months. Most hemangiomas disappear or fade by age 10 years.¹ However, they may leave a mark. Some children with deep hemangiomas or hemangiomas that leave a scar may need plastic surgery.