Newshub headline with Children's Wisconsin logo
Birthmarks Children's Wisconsin

Mother’s marks: When is a birthmark something serious?

Often, parents will bring my newest patients to their newborn well visits with lots of questions, which I welcome and are an important part of well visits. One common question I hear is, “what is this mark on my baby?” Typically, they are referring to birthmarks. Overall, birthmarks are harmless. But let’s take a look at common birthmarks and if you need to worry about them.

What is a birthmark? 

A birthmark is a colored mark on or under the skin that is present at birth or develops shortly after birth. Some birthmarks fade with time while others may become more pronounced. Most birthmarks are painless and harmless. In rare cases, however, they can cause complications or be associated with other conditions. All birthmarks should be checked by a doctor and they are something I look out for as a pediatrician.  

Types of birthmarks


Hemangiomas are also known as strawberry marks. A hemangioma is a bright red birthmark that shows up at birth or in the 1st or 2nd week of life. It looks like a rubbery bump and is made up of extra blood vessels in the skin. They grow rapidly in the first 12 months, and then gradually reduce in size over the next three to 10 years, often leaving a slight discoloration or puckering of the skin.
A hemangioma can occur anywhere on the body, but most commonly appears on the face, scalp, chest or back. Typically, they are harmless and fade over time. If one of my patients has a hemangioma, I monitor it to make sure it doesn’t interfere with vision, breathing or other functions. If it appears to be causing issues, I refer families to a specialist who can treat the hemangioma, typically a pediatric dermatologist or pediatric ears, nose and throat doctor. You should always contact your child's pediatrician if the hemangioma bleeds, forms a sore or looks infected.

Port wine stains

Port wine stains are another common birthmark. They got the name because they look like red wine was spilled or splashed on the skin. They often start out looking pink at birth and tend to become darker (usually reddish purple or dark red) as kids grow. They can be found anywhere on the body, but most commonly are on the face, neck, scalp, arms or legs. They can be any size and usually grow in proportion as a child grows.

For most kids, port wine stains aren’t harmful. You might not even notice port wine stains, especially when they're not on the face. However, port wine stains often get darker and can sometimes become embarrassing for children, particularly during the already challenging preteen and teen years. 

Port wine stains won't go away on their own, but they can be treated. Laser therapies can make many port wine stains much less noticeable by shrinking the blood vessels in the birthmark and fading it. They often change in texture over time, too. Early on, they're smooth and flat, but they may thicken during adulthood. 

I tell parents to keep an eye on port wine stains as they can get very dry sometimes, so it's important to use a moisturizer on the affected skin. It’s important to call your child’s pediatrician if the port wine stain ever bleeds, causes pain, itches or appears infected. Rarely, port wine stains may be a sign of other disorders, but usually not. And again, doctors should be keeping an eye on port wine stains at well visits to make sure everything looks normal.

Salmon patches (stork bites or angel kisses)

Salmon patches, also known as stork bites or angel kisses, are a common birthmark that form on a newborn’s skin, typically on the back of the head or neck. These marks are caused by collections of capillary blood vessels close to the skin. They appear as pink, red or purple marks on the skin and do not need treatment because they are harmless and will fade over time.
These marks are really common. Actually, up to 30 to 40 percent of newborns will have these little marks. 

Café-au-lait spots 

Café-au-lait describes the light brown color of these common birthmarks. The marks are flat and usually round or oval shaped. Most are smaller than a child's palm and have smooth borders. Seen at birth or in the 1st year, they won’t fade but can be treated with lasers if you’re bothered by them. 

Most café-au-lait spots are harmless. They are unlikely to turn into skin cancer, but may become darker with more sun exposure. Multiple café-au-lait spots can be a sign of other conditions, including one called neurofibromatosis. If your child has a large café-au-lait spot, more than five spots, or spots in the armpits/groin, make sure you talk with your pediatrician about them.

Slate gray nevus 

A slate gray nevus is a usually harmless, large, blue-gray birthmark that can often be mistaken for a bruise. While seeing a birthmark that resembles a bruise can be startling to parents and caregivers, it is important to know that this birthmark is completely normal, totally harmless and isn’t painful. This type of birthmark is more common in kids of East Asian, Polynesian, Indonesian and Native American descent. It usually appears on the lower back, butt or shoulders. A slate gray nevus tends to fade by about age 4, but some can remain through adulthood. This birthmark requires no treatment. 

Bottom line

The skin is our body’s largest organ, so it’s important to take good care of it and be aware of anything that affects it. Parents, please never hesitate to ask your child’s pediatrician about skin concerns or anything regarding your child’s health and wellness. We are your partners in helping your child live a healthy life.