Port wine stain

Port wine stains

Port wine stains are the most common vascular malformations. They occur in about 1 out of every 1,000 people. A port wine stain is an area of skin in which the small veins just under the surface of the skin are dilated. This dilatation will increase the amount of blood in the veins and this will impart a reddish stain to the skin. The underlying cause of the dilatation of these vessels is believed to be an absence of innervations (nerve connection) to the muscle wall surrounding the small veins. Since the embryo develops segmentally (in parts, with each part developing independently), usually only one or two segments may be involved, occasionally, the condition can be more widespread. The absence of nerve connection will result in a muscle wall that has no tone (function) and this in turn will cause these vessels to dilate, hence the increase in blood volume in these vessels and hence the discoloration. Since the blood circulation is dynamic, the intensity of color will vary according to the volume of blood present within the vessels.

Although we group all port wine stains together, there are clearly different types of port wine stain. To date, no sub classification has been proposed. Some port wine stains are darker than others. This is probably due to the density of affected vessels. Some are confluent whereas others are geographic in their distribution.

The intensity of color will vary as the blood flow varies. When the patient is hot or angry, the flow of oxygenated blood will impart a more intense, reddish discoloration to the lesion. The process of aging will affect the port wine stain. A slow steady dilatation of the vessels will result in an increase intensity of color and as the amount of elastin and collagen diminishes, the port wine stain will thicken. Some will form nodules called cobblestones which can get quite large if left untreated. The age of onset of these cobblestones varies from the mid 20's to the 60's. It must be stressed that cobblestone formation is not inevitable. In an even smaller percentage of patients, there will be tissue overgrowth or thickening of the soft tissues within the affected area. The exact cause of this is unknown but it appears to be a segmental growth signal abnormality.

Port wine stains may be associated with syndromes, the most important of which is Sturge Weber Syndrome. This condition is an association of a portwine stain, ocular (eye) involvement and involvement of the meninges (the membranes that cover the brain). In its worst form, this syndrome can cause seizures, mental retardation and visual loss. This is NOT inevitable and the reader should be referred to a site that specializes in Sturge Weber Syndrome. Many patients with Sturge Weber Syndrome have very mild disease and live completely normal lives. For more information on Sturge Weber Syndrome.  http://www.sturge-weber.org 

Eye involvement without brain involvement does occur and is more commonly seen if there is skin involvement above and below the eye. This is not Sturge Weber Syndrome. These children should be seen by an ophthalmologist in order to correctly diagnose whether or not there is eye involvement and if so, to treat and prevent complications.

Laser Treatment

Portwine stains were amongst the first lesions to be successfully treated by lasers. The standard of care at this point in time involves the use of a Pulsed Dye Laser. Almost all lasers these days have some sort of cooling device. Once again, an experienced physician is always desirable. The rate of complications is extremely low and in the vast majority of cases, the portwine stain should lighten significantly with treatment. Only a small percentage of portwine stains will disappear with treatment (10-12 %). There are a few important principles. Geographic, non confluent (normal/uninvolved skin within the port wine stain) do much better than confluent (NO normal/uninvolved skin within the area of the portwine stain). This does not mean that confluent portwine stains will not do well. Early treatment is advantageous. The younger the child the more efficacious the treatment. The very first treatment seems to be the most important, especially when dealing with a young child. Some areas appear to do much better than others. Central facial lesions do well. Forehead and eyelid lesions also do well, as do temple lesions. Central cheek portwine stains fare worst of all facial portwine stains. Shoulder and upper chest lesions do well. Upper arm lesions do better than the lower part of the arm. Hand and feet lesions do worst of all.

It will usually take between 6 and 10 treatments to get maximum lightening. The timing of the interval between treatments is arbitrary. We usually space treatments 6 – 8 weeks apart during the first few treatments but, as the treatment advances, the interval between treatments increases to 3 months and eventually 6 months.

One of the controversies concerns the recurrence of portwine stains after treatments. Since laser treatment is aimed at the effect and not the cause of portwine stains, it stands to reason that the lesion will eventually return. All this means is that the patient will need a "maintenance" treatment every few years in order to keep the desired effect.

Surgical treatment

A small percentage of patients with portwine stains experience cobblestone formation and/or soft tissue hypertrophy. Cobblestones usually develop in the 4th or 5th decades of life and are nodules that appear on the surface of the portwine stain and over the course of several years, increase in size. Cobblestones can bleed, become painful and quite large. Soft tissue hypertrophy refers to a thickening of the tissues involved in the portwine stain. The tissues involved continue to grow. Growth takes place in all of the tissue layers and this usually commences and is noticeable at a much younger age.

Both of these conditions can be surgically corrected. Once again, surgery is not "curative" but the results are usually long term.

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