Capillaries are small blood vessels that connect the arteries to the veins. A capillary malformation, also called a port wine stain, is a type of birthmark. If your child has a capillary malformation, the capillaries are larger than normal (dilated) in the area of the birthmark.

The capillaries in a capillary malformation:

• Are present at birth (congenital)
• Produce a flat birthmark
• Are close to the surface of the skin, which makes the skin color pink to red
• May be difficult to see if your child has darker skin
• Can be on any area of the body or in many areas, but are most common on the head and neck

The cause of capillary malformation is unknown. We do know that they are not caused by anything you did or didn't do during pregnancy.

A capillary malformation may cause complications, such as:

• Changing appearance: The skin involved in capillary malformation tends to get darker and thicker over time.
• Bleeding: If the skin thickens, it may bleed easily. Laser treatments seem to help the skin stay lighter in color and thinner.
• Glaucoma: If your child's capillary malformation is on one or both eyelids, it may be a sign of underlying glaucoma. Glaucoma is caused by an increased pressure in the eye. This can lead to blindness. Your baby should be checked for glaucoma by a pediatric ophthalmologist shortly after birth. Your baby should be seen on a regular basis to monitor the pressure.

More Information About Capillary Malformations/Port Wine Stains

You might also want to know:

• Sometimes capillary malformations are the sign of a more serious syndrome. So even if you aren't considering treatment for your child, it's important to have a specialist perform an examination to find out whether there is something more serious going on.
• Capillary malformations will not go away on their own if they are left untreated. And although they do not spread or take over a larger area, capillary malformations will grow as your baby grows.
• Most capillary malformations will not require surgery. However, if the soft tissue under the malformation is overgrown, surgery may be an option.

Parents have a range of emotions when their baby is born with a birthmark, so no matter what you're feeling or thinking, understand that it's normal. If your child has a birthmark on their head or neck, people may stare, make rude comments or even accuse you of child abuse. All of those things have the potential of affecting your child.

Children often become aware of their appearance around 4 years of age. If you're worried about self-esteem issues related to your child's birthmark, watch for signs from your child. Some children try to hide their birthmark or suddenly refuse to go places they used to enjoy. Signs like that may indicate that your child feels uncomfortable with the birthmark.

There are resources that can help with the emotional aspects of a birthmark. The vascular anomalies team at Children's Wisconsin is one resource. We also have child life specialists who can help. Sometimes family members like to talk to another family with the same concerns. If that's something you'd be interested in, our vascular anomalies team can help you make contact with another family.