What Is a Birthmark? (2024)

Birthmarks are marks on or under the skin that are present at birth or develop by 1 to 2 years of age. Birthmarks can be vascular or pigmented. These two types are divided into subtypes that vary in shape, size, color, and texture.

Most birthmarks are harmless, but in some instances, they may be a sign of a more serious condition, particularly if they occur in large numbers or clusters.

This article explains causes of birthmarks, types, and how to care for a birthmark when needed.

Vascular Birthmarks

Vascular birthmarks are made up of blood vessels close to the skin's surface, giving them a red appearance. They can be raised or flat. They are typically red and may grow large. There are several types of vascular birthmarks.

Hemangiomas

Hemangiomas occur in up to 5% of newborns and are more common in girls and in babies who are premature. They can manifest in one of two ways.

Strawberry hemangiomas:

• Are bright red
• Occur near the surface of the skin
• Can appear flat and splotchy or as raised bumps that are firm and rubbery
• May open into a sore, more commonly when located near a body opening or body fold

Deep hemangiomas:

• Develop in deeper layers of the skin
• Appear as raised blue–gray bumps
• May only become noticeable weeks or months after birth
  

Hemangiomas tend to grow quickly in the first year, then flatten out and start to fade. Often, they are completely faded by age 10. Sometimes, a slight discoloration or rippled texture may remain on the skin.

Some hemangiomas require medical care as they can damage other tissues if they develop on the lip or eyelid, on organs, or on other structures within the body.

Children with groups of hemangiomas that appear in a "beard" pattern around the mouth, chin, or one side of the face—or who have multiple small, raised birthmarks that spread across the skin—are more likely to have internal hemangiomas.

Salmon Patches

Salmon patches are also called:

• Vascular stains
• Macular stains
• Angel's kisses
• Stork bites

They are small, flat, pink, or red marks caused by a cluster of blood vessels. They are the most common type of vascular birthmark, occurring in one-third to one-half of all babies.

The mark becomes more noticeable when the baby is overheated, irritated, having a bowel movement, or crying.

Salmon patches can occur anywhere on the body, including the back of the neck, the forehead, the eyelids, or the lips. They are usually harmless. They typically fade within the first year, but those on the nape of the neck may last longer.

Port Wine Stains

Usually present at birth, port wine stains start out as flat pink or red areas, commonly on the face, and can thicken and darken to deeper red or purple. They can also grow in size.

Though rare, port wine stains may indicate the neurological disorder Sturge-Weber syndrome, particularly when the birthmark covers half of the face or more. This medical condition causes an increased risk of glaucoma (because of increased pressure in the eye) and may cause seizures due to abnormal blood vessels in the lining around the brain.

Venous Vascular Malformations

Venous vascular malformations appear red or purple. They are caused by groups of unusually dilated or enlarged veins.

They grow slowly and can appear from birth through late childhood. They don't fade on their own but can be treated if necessary.

Pigmented Birthmarks

Pigmented birthmarks are marks or areas that differ in color from the rest of the skin. There are several different types.

Café-au-Lait Spots

Café-au-lait spots are flat, brown, roughly oval-shaped marks that can be present at birth but often develop later (into early childhood). On light skin, they may appear the color of coffee with milk, while on dark skin, they may be the color of black coffee. They are caused by excess melanin production (natural pigment produced by skin cells).

These spots vary greatly, from the freckle size to covering a large skin area.

Café-au-lait spots are common, affecting up to 30% of children by age 6. They are usually harmless, but six or more spots may indicate a larger health problem, such as neurofibromatosis.

Dermal Melanocytoses

Dermal melanocytoses are flat, irregularly shaped blue-gray patches usually found on the back and buttocks. They often are apparent at birth.

These birthmarks vary in size and may be mistaken for bruises. They are harmless and usually fade by the age of 3 to 5 years.

Congenital Nevi

Congenital nevi are moles that are present at birth. They can vary in appearance and may:

• Be small or large
• Be light, dark brown, or almost black in color
• Be flat or bumpy
• Darken, thicken, or grow hair
• Appear anywhere on the body
  

Unlike moles that develop later in life, congenital nevi are less commonly associated with skin cancer but should be checked regularly. See your child's healthcare provider if you notice changes. The risk of cancer development is greater if the mole is larger than 8 centimeters.

Most congenital moles are harmless, but many small moles present at birth as excess pigmented cells growing in the central nervous system. Babies with this presentation should be seen by a dermatologist as this can cause pressure on the brain and seizures if not addressed.

Sebaceous Nevi

Usually found on the scalp, sebaceous nevi are tan or orange patches that are often hairless (or nearly hairless) and slightly raised. They are caused by an overgrowth of sebaceous glands (glands that secrete a waxy substance to moisturize skin and hair).

They are present at birth and may change over time, such as becoming thicker or changing color, but they do not go away.

The risk is low, but sebaceous nevi may become cancerous and should be monitored by a dermatologist or healthcare professional.

Hypopigmented Macule

Hypopigmented macules are skin areas lighter in color than the surrounding skin. They can be raised or flat and vary in shape (commonly round, oval, or leaf-shaped). They can develop anywhere but are usually found on the chest, abdomen, back, or buttocks. Most go away on their own.

What Causes Birthmarks?

What causes a birthmark to develop is usually not known. Most of the time, they happen by chance. They are not caused by anything the pregnant parent did during pregnancy. They are not believed to be inherited.

Some factors are more common in certain birthmarks.

Hemangiomas, for example, are more common in babies who are:

• Female
• Premature
• White
• Less than 5.5 pounds at birth
• Part of a multiple birth (twin, triplet, etc.)

Dermal melanocytosis is more common in babies of Asian heritage and in those with darker skin.

When to Be Worried About Birthmarks

Birthmarks are usually harmless but may indicate an underlying problem or cause complications in rare cases:

• If it's large and on the face, head, or neck
• If it's located in the middle of the back, along the spine
• If it's a port wine stain on the leg
• If it's located on or around the eye or another place that interferes with movement or functioning
• If you have multiple, birthmarks such as more than six, café-au-lait spots

A healthcare provider may order tests, such as:

• Skin biopsy
• Computed tomography (CT) scan
• Magnetic resonance imaging (MRI)

You should also monitor the birthmark for changes such as:

• Change in color
• Change in size
• Change in texture
• Bleeding
• Pain
• Ulceration (open sore)
• Inflammation
• Itching

When to See a Healthcare Provider

Most birthmarks are harmless but talk to your healthcare provider about removal in the following situations:

• It is a strawberry hemangioma on the face (near the eye, mouth, or nose) or groin.
• It is a port wine stain (see a healthcare provider early, before growth and thickening occur).
• It greatly impacts appearance and may cause problems with self-esteem or emotional distress.
• There are changes in a mole or another birthmark.
• It is painful.

Procedure to Remove or Shrink Birthmarks

Birthmarks should be removed if they are causing problems or if they have concerning features. You may also want to have your birthmark removed for cosmetic reasons.

Laser Therapy

Laser therapy eliminates blood vessels or pigment just below the skin's surface and is mainly used for port wine stains and birthmarks close to the skin surface.

Laser therapy typically needs to be repeated. It's most effective when started in infancy; for port wine stains, laser therapy can be started within the first few days after birth.

Surgery

Surgery removes the birthmark. Surgical procedures are typically used for moles or other birthmarks that could become cancerous, for deep hemangiomas, or for a birthmark that is large, raised, and affecting appearance.

Cryotherapy

This type of therapy involves freezing the birthmark to eliminate abnormal tissue.

Medications

Some medications are injected into or applied to the area, and others are taken orally. Medications may include:

• Corticosteroids
• Interferon
• Propranolol
• Timolol

Summary

A birthmark is a mark on or under the skin that is present at birth or appears in early childhood. Birthmarks vary in appearance.

Most birthmarks are harmless, but they should be checked and monitored by a healthcare professional. Rarely, birthmarks can be a sign of a more serious condition or can lead to complications.

Procedures and therapies that may be used on birthmarks include laser therapy, surgery, cryotherapy, and/or medications.