Birthmarks Symptoms & Causes

We’ve tried to provide some answers to those questions in these pages. If you have further questions or concerns, talking to your child’s doctor is a good place to start.

Is my child’s birthmark medically serious?

Most birthmarks are harmless, but there are a few that can require treatment based on where they're located and whether they’re growing. It’s a good idea to have your pediatrician check out your baby’s birthmark just in case.

How common are birthmarks?

They’re pretty common—approximately one in three babies has a birthmark.

What causes birthmarks?

The cause of most birthmarks is still unknown. Doctors agree that no known food, medication or activity during pregnancy can cause a birthmark.

Is my child’s birthmark painful?

In most cases, no. There are certain situations where a birthmark can cause your child some pain; for more information about a particular birthmark, talk to your pediatrician.

Types of birthmarks

There are two main types of birthmarks:

  1. Vascular birthmarks are caused by incorrectly formed blood vessels in your child’s skin. Examples include:

    • infantile hemangiomas: the most common vascular birthmark, it usually appears within one to two weeks of birth.

      Infantile hemangiomas grow rapidly during the first few months of life and then begin to shrink and fade when your baby is around 1 year old. Most of the time, they cause no problems and go away on their own.
    • capillary malformation, or "port-wine stain": flat, red-pink stain that usually appears on your child's face or neck. It’s a mostly cosmetic problem that usually doesn’t need any treatment at all. But if it doesn’t go away and is in a prominent location, you may want to consider pulsed dye laser therapy for your child. 
    • nevus flammeus (“salmon patch” / “angel's kiss” / “stork bite”): pinkish birthmarks that appear on your child’s forehead, eyelids or neck. They usually fade significantly by the time your child is 2 years old. Nevus flammeus birthmarks don’t require any treatment.
  2. Pigmented birthmarks are caused by an overproduction of pigmentation. Examples include:

    •  café au lait spot: flat, tan spots that can appear anywhere on your child’s body. They’re completely harmless, but if your baby has more than five of them, you should have her screened for neurofibromatosis or other genetic conditions.

    • slate gray nevus (“Mongolian blue spot”): large, blue-gray birthmarks that resemble bruises and commonly appear on the lower back. They’re completely harmless and usually fade without any treatment.

    • congenital nevus (“mole”): raised brown spots which are extremely common and can appear anywhere on your child’s body. If your child has a very large mole, you should have it checked out by a pediatrician, as it could increase her risk for skin cancer.


Q: Should my child see a vascular anomalies specialist?
Since most birthmarks are completely harmless, most children don’t need to see a specialist. Your child’s pediatrician will keep an eye on the birthmark, provide reassurance and support and put you in touch with a specialist if the situation warrants.

It’s rare that a birthmark is a sign of an underlying abnormality, but it does happen. We do recommend consulting with a vascular anomalies specialist if:

  • your child’s pediatrician is uncertain about the diagnosis
  • your child has any symptoms connected with the birthmark (such as pain, swelling or bleeding)
  • the birthmark seems to be growing

Q: Is my child’s birthmark permanent?
A: Birthmarks come in all shapes and sizes. Some are permanent, and others fade as your child grows.

Q: Did I do something during pregnancy to cause the birthmark?
No–there's no known food, medication or activity during pregnancy that can cause a birthmark.