Health Library

Capillary Malformations

What Causes a Capillary Malformation?

A genetic change (mutation) has been found in affected skin but not in nearby normal skin. This change is not caused by anything the mother did during pregnancy, like taking medications or being exposed to certain environments.

Another mark on the skin that is often confused with capillary malformations are nevus simplex birthmarks, which are seen in newborn infants. These appear in the middle of the face, neck or back, and are known "angel kisses." On the back of the neck or scalp they are called "stork bites." These birthmarks have a typical pattern on the skin and usually fade by 1-2 years of age. They do not require treatment.

What Do Capillary Malformations Look Like?

Capillary malformations look pink, red or purple due to an increased number and size (diameter) of blood vessels involved in comparison to normal capillaries of the skin. As your child grows, the affected blood vessels may continue to enlarge and thicken. This will cause the color of the mark to darken. Over time, clusters of tiny, dilated venules (small vessels that collect blood from the capillary junctions and join to form veins) may give a lumpy look to the skin.

How Are Capillary Malformations Diagnosed?

Most capillary malformations are diagnosed with a medical history and physical exam alone. Sometimes imaging with ultrasonography or magnetic resonance imaging (MRI) is needed to exclude similar or related conditions.

What Are the Possible Complications?

Capillary malformations on the face can darken over time and the skin might thicken and form nodules (become “lumpy”). Inflamed, bright red, raised marks called pyogenic granulomas may develop on or near the birthmark and are prone to bleeding.

When the capillary malformation involves the forehead and / or upper eyelid, it can be linked with brain or eye problems (Sturge-Weber syndrome). If located around the eye, a patient should have regular eye exams to look for glaucoma (increased pressure in the eye). A special scan called magnetic resonance imaging (MRI) may be used to determine if there are any brain changes related to Sturge-Weber syndrome. Capillary malformations in the skin directly over the spine can be associated with spinal abnormalities. These malformations should be investigated with an ultrasound or MRI of the spine.

How Are Capillary Malformations Managed?

Laser therapy is the standard treatment for capillary malformations on the face. One goal of treatment is to prevent the skin from thickening and improve appearance. Often, several treatments are needed. Laser therapy can be uncomfortable, so doctors might use numbing cream on top of the area being treated, sedation or even general anesthesia. Very few malformations go away completely. If laser therapy doesn’t work, surgery might be an option, especially if there’s significant skin thickening.

What Are the Risks and Side Effects of Treatment?

There are risks for both laser therapy and surgery. The risks of laser therapy can include blisters, scarring and changes in skin color. Even with laser treatment, a capillary malformation may return after several years. The risks of surgery depend upon the type of surgery performed. General risks of surgery include infection, bleeding and scarring.