A purple birthmark.
A type of vascular birthmark or blood vessel malformation. Port-wine stains can be pink, red, or purple and of any size, and they occur most often on the face, neck, arms, and legs. They tend to increase in size as a child grows and do not disappear on their own. It is essential for a doctor to diagnose this type of birthmark and monitor its growth, especially if it is on the forehead, eyelids, or sides of the face. Large port-wine stains at these sites are associated with an increased risk of glaucoma or seizures. A port-wine stain may also form a pyogenic granuloma (a small, inflamed bump on the skin that bleeds easily), which usually must be surgically removed. Many port-wine stains can be removed with laser surgery, which destroys the blood vessels.
A persistent, non-elevated type of hemangioma characterized by a purplish-red birthmark. Port-wine stains are indicative of Sturge-Weber syndrome.