Symptoms:

Early port-wine stains are usually flat and pink in appearance. As the child gets older, the color may deepen to a dark red or purplish color. They occur most often on the face but can appear anywhere on the body. Over time, the area can become thickened and take on a cobblestone-like appearance.

Signs and tests:

Your doctor can usually diagnose a port wine stain by looking at the skin.

In unusual cases, a skin biopsy may be needed. Depending on the location of the birthmark and other symptoms, your doctor may want to do an intraocular pressure test or x-ray of the skull.

An MRI or CT scan of the brain may also be done.