Port-wine stains are birthmarks. They are most commonly located on the face but can also appear anywhere on the body. Port-wine stains are caused by overly-dilated blood capillaries close to the surface of the skin. The resulting collection of the blood gives port-wine stains their distinctive appearance, which can range from light pink to purple in color. Port-wine stains are usually benign but can also be a sign of underlying health conditions. Your primary health care provider can determine if additional testing is necessary. In the meantime, port-wine stain appearance can be improved. At SF Bay Cosmetic Surgery & Aesthetic Dermatology we use IPL to fade port-wine stains and other vascular irregularities. IPL works by heating abnormal blood vessels, which in turn causes them to close up and disintegrate within weeks. Multiple treatments are usually needed to produce best results.