The incidence is 3 out of 1,000 people. Port wine stains occur most often on the face but can appear anywhere on the body.
Early stains are usually flat and pink in appearance.
As the child matures, the color may deepen to a dark red or purplish color. Significant hypertrophy may produce distortion of the facial features. The presence of PWS can cause emotional and social problems for the affected person because of their cosmetic appearance. PWS may be one of a group of symptoms and signs in which case it is considered to be part of a syndrome. There is no known prevention.