What are Capillary Malformations? 

Capillary malformations (CM) result from an increased number of capillaries (the smallest blood vessels) concentrated in the superficial skin layers, leading to an increase in blood flow in that area of skin. Because the lesions are close to the skin surface, the increased blood flow at the site causes an externally visible red mark or "stain." CMs are present at birth and are often located on the head and neck area but can appear on any part of the body. Capillary malformations are equally common in males and females, as well as in full-term and premature infants.

Some capillary malformations may indicate the presence of other rare conditions such as Sturge-Weber syndrome, Parkes Weber syndrome, Klippel-Trenaunay syndrome, Proteus syndrome and macrocephaly-capillary malformation syndrome. CMs that extensively involve the eyelids may be associated with the development of glaucoma.

Recent research suggests that some CMs may be the result of a genetic mutation that occurs shortly after conception. While the exact cause is not completely understood, experts agree that CMs are not caused by anything the mother did during her pregnancy. There are no known ways to prevent this condition.

Signs & Symptoms

Capillary malformations are well-defined pink, red or purple patches on the skin. CMs grow in proportion to the child. In some cases, the color of the CM lightens somewhat over the first few months of life. CMs that are darker red or purple are often called port wine stains. The surface of port wine stains may change over years, sometimes developing a bumpy or thickened texture.

A frequently encountered type of capillary malformation is located on the central forehead, median eyelids, nose or upper lip and is often referred to as an "angel kiss." Similarly, CMs are frequently present on the nape of the neck and are referred to as "stork bites." Other medical terms for these specific CMs are "salmon patch" and "nevus simplex." These CMs may represent the residual circulatory system present in the developing fetus. These vascular markings generally fade in intensity over the first few years of life and are not associated with complications.


Most capillary malformations can be diagnosed by a physical exam. Because select capillary malformations can be associated with other findings, a physician may suggest additional examinations or diagnostic tests in some circumstances.


Capillary malformations are commonly treated with a pulsed-dye laser (PDL), which uses a light beam to gradually destroy the dilated blood vessels. While many CMs will lighten by up to 50 percent with this treatment, only 15 percent will nearly disappear.

Repeated laser treatments are often necessary to accomplish lightening of the CM. Capillary malformations located around the eye, lateral cheeks, chest and shoulders/upper arms respond best to laser treatment, while the central face/nose and distal arms and legs are less responsive to this therapy.

Pulsed dye laser treatment can be started in the first year of life and has been shown to have some of its best effects when begun early in life. Subsequent treatments every few years are often necessary to maintain the benefit of the laser therapy.

For capillary malformations that do not respond to PDL treatment, other therapies may be recommended, including the use of different lasers or surgical interventions. The vascular anomalies team is available to discuss potential treatment options for children with CMs.

Why Choose Us?

The vascular anomalies program at Comer Children's offers an integrated and comprehensive approach to the diagnosis, care and management of vascular malformations. Our multidisciplinary team of pediatrics experts works together to educate families and to evaluate and treat children with all types of these vascular lesions.

Resources & Support for Patients with Vascular Anomalies

Patient Resources at Comer Children’s

Kids want to feel like kids, even when they're sick. Our Child Life therapists use play, art and other approaches to take some of the scare away from the hospital experience and to help kids feel as normal as possible, in spite of their disease. Located near Comer Children's, the Ronald McDonald House provides a home away from home for families while their child is hospitalized.

Patient Resources & Support Groups

These organizations and support groups may be helpful to families and patients by providing support, education and treatment information on vascular anomalies.