Overview
A port-wine stain is a type of birthmark that is caused by a malformation of tiny blood vessels called capillaries. The name port-wine stain comes from the color of the birthmark, which ranges from light pink to a dark red color. Other small birthmarks that are related to port-wine stains are sometimes called salmon patches, which may also be called angel kisses (when they are on the baby's face) and stork bites (when they are on the back of the baby's neck). Like port-wine stains, salmon patches start as flat, pink or red patches; the difference between these birthmarks is that salmon patches tend to fade in the first year of life while port-wine stains become darker and grow along with the baby.
In the past, port-wine stains and salmon patches were considered to be variations of the same kind of birthmark, but now it is now known that port-wine stains are truly malformations of capillaries and will never improve on their own, while salmon patches are temporary dilatations (expansions) of capillaries that do typically improve on their own.
These birthmarks are noncancerous, but port-wine stains are sometimes associated with other syndromes involving the brain and development. Klippel-Trenaunay syndrome involves malformations of the veins (venous malformations), port-wine stains (capillary malformations), and excessive growth of the soft tissues. Additionally, some individuals with Klippel-Trenaunay syndrome have one limb that is longer and larger than the other limb. The syndrome is most frequently diagnosed in infancy or early childhood.
