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. This may be due to problems with the nerves controlling 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


The marks vary in size and are usually located on the head or neck, but may be in other locations

Appearance may change over time:

  • In children—they are flat, red, or light purple
  • In adults—they are raised and purplish in color, darkening and thickening over time

They may be prone to bleeding when scratched.

A port-wine stain near the eyes may be due to Sturge-Weber syndrome, and 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. Other tests, such as eye examination or imaging, may be done if Sturge-Weber syndrome is suspected.

Skin Biopsy

Skin proceedure
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Port-wine stains are generally harmless. They may occasionally result in dry skin, which may need moisturizing.

They may also cause emotional and social problems due to their visibility. Counseling may be considered.

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


There are no current guidelines to prevent port-wine stains.