A port-wine stain is a mark that is usually present at birth. It is made of enlarged blood vessels. This makes it appear as a reddish-purple patch of skin.


Port-wine stains are caused by a problem with the small blood vessels in the skin. Blood vessels can normally open and close to meet the needs of the skin. In port-wine stains, the blood vessels stay open. Blood fills the vessels causing the purple color and raised skin. It is not clear what causes the problems with the blood vessels.

Risk Factors

There are no known risk factors for port-wine stains.

Conditions associated with port-wine stains include:

  • Sturge-Weber syndrome
  • Klippel-Trenaunay-Weber syndrome


Symptoms include a mark that may be:

  • Reddish or purplish in color in adults
  • Raised in adults
  • A flat, red, or light purple lesion in children
  • On the head or neck
  • Prone to bleeding when scratched
  • Dark and thick over time

A port-wine stain near the eyes may cause additional symptoms.


A port-wine stain can typically be diagnosed based on its appearance. In some rare cases, a skin biopsy may be done.

Skin Biopsy

Skin proceedure
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Port-wine stains are generally harmless. They may cause emotional and social problems due to their visibility.

Talk with your doctor about the best treatment plan for you. Treatment options include:


Laser treatment may be used to destroy the blood vessels causing the stain. There are some risks with laser treatment. It may result in scarring and skin lightening or darkening.

Flash-lamp pumped pulse dye laser is one type used with port-wine stains. Multiple treatments may be necessary.

Other Treatments

Other treatment options include freezing, surgery, tattooing, and radiation. These treatments have had limited success. Lasers have replaced most of these treatments.


Port-wine stains cannot be prevented.