Portwine stainhttps://en.wikipedia.org/wiki/Port-wine_stain
Portwine stain is a discoloration of the human skin caused by a capillary malformation in the skin. They are so named for their coloration, which is similar in color to port wine, a red wine from Portugal. Portwine stain is a capillary malformation, seen at birth. Portwine stain persist throughout life. The area of skin affected grows in proportion to general growth.

Portwine stain occur most often on the face but can appear anywhere on the body, particularly on the neck, upper trunk, arms and legs. Early stains are usually flat and pink in appearance. As the child matures, the color may deepen to a dark red or purplish color. In adulthood, thickening of the lesion or the development of small lumps may occur.

Vascular lasers are somewhat effective, but require expensive laser equipment and long-term treatment over several years. As lesions thicken with age, laser treatment may become less effective, which can be a problem. Pink lesions are generally more difficult to treat than red lesions because they are deeply vascularized.
#Dye laser (e.g. V-beam)
  • Portwine stain can be treated with a laser, but it is expensive and time-consuming.
    References A retrospective 10 years‐ experience overview of dye laser treatments for vascular pathologies 37632184 
    The Flash‐lamp pulsed dye laser (FPDL) is nowadays considered the most precise laser currently on the market for treating superficial vascular lesions. In this study, we gathered data from 10 years of experience regarding dye laser treatment of patients presenting vascular malformations such as telangiectasia, rhinophyma, port‐wine stain, cherry and spider angioma and vascular tumours: cherry angioma, infantile haemangioma, port wine stain, rhinophyma, spider angioma, telangiectasia
     Nevus Flammeus 33085401 
    Nevus flammeus or port-wine stain (PWS) is a non-neoplastic congenital dermal capillary hamartomatous malformation presenting as a pink or red patch on a newborn's skin. It is a congenital skin condition that can affect any part of the body and persists throughout life. The nevus flammeus is a well-defined, often unilateral, bilateral, or centrally positioned pink to red patch that appears on the face at birth and is made up of distorted capillary-like vessels. It needs to be differentiated from a nevus simplex/salmon patch, which is usually seen along the midline and disappears over time. An acquired port-wine stain, clinically and histopathologically indistinguishable from congenital capillary malformation, has been reported to develop in adolescents or adults, usually following trauma.
     Consensus Statement for the Management and Treatment of Port-Wine Birthmarks in Sturge-Weber syndrome 33175124 
    Treatment of PWB is indicated to minimize psychosocial impact and diminish nodularity, and potentially tissue hypertrophy. Better outcomes may be attained if treatments are started at an earlier age. In the United States, pulsed dye laser (PDL) is the gold standard for all PWB regardless of the lesion size, location, or color. When performed by experienced physicians, laser treatment can be performed safely on patients of all ages. The choice of using general anesthesia in young patients is a complex decision which must be considered on a case by case basis.