Port
Wine Stains (Capillary Vascular Malformation)
Definition
A port-wine stain (PWS) is a red or purple birthmark due
to an abnormal collection of dilated and twisted blood vessels
in the skin. Under the microscope skin is divided into two
layers; the uppermost is the epidermis, the deeper layer
the dermis. The skin layer involved is the dermis and the
blood vessels affected are the capillaries.
Incidence/Age/Sex
In the Caucasian population the reported incidence of PWS
is 0.3 %. In contrast to haemangiomas PWS are always present
at birth; in some instances they may go unnoticed. Males
and females are equally affected.
Causes/preventions
The cause of these birthmarks is unknown. Contrary to many
oldwives tales the appearance of a PWS has nothing to do
with what the mother ate or saw during her pregnancy.
Signs & Symptoms
The typical PWS is obvious at birth and appears as a flat,
smooth intense purple stain on otherwise normal skin. A
PWS most commonly affects the head and neck; certain parts
of the face are classically affected. The area of the face
most typically affected can be divided up into thirds around
the eyes, nose and mouth; one or more of these areas may
be affected in any one individual. Some PWS may be any shade
of red or pink. A PWS does not lighten (blanch) under fingertip
pressure.
The problems with PWS are mostly cosmetic and psychological;
however, some PWS are associated with other problems and
it is important these are identified early.
With increasing age the appearance of a PWS changes; the
surface may develop localised lumps and become generally
rough to touch. In contrast to haemangioma they grow slowly,
at the same rate as the child and do not improve in appearance,
as the child gets older. PWS “grow with the child”
and grow in proportion to the child.
Complications of disorder
Port-wine stains themselves have no physical complications;
however some are associated with other conditions which
may have implications for the affected child. PWS around
the eyes and nose may be associated with an eye condition
known as glaucoma. In glaucoma the pressure inside the eyeball
is raised; untreated this can lead to progressive loss of
vision. Some PWS, also around the eye and nose, may also
be associated with an abnormal collection of blood vessels
on the brain; this can be associated with fitting and mental
retardation. Rarely PWS may be associated with gigantism
of an affected limb.
Tests
The diagnosis of a PWS is made based upon its appearance
and behaviour; tests are not usually needed to make the
diagnosis. However, if the eye and nose area of the face
are affected then an ophthalmologist who can measure the
pressure in the eye to decide if glaucoma is present should
see the baby. The opinion of a paediatric neurologist should
also be sought and sometimes CT scans to see if the brain
is involved may be ordered.
Treatment
The treatment of port-wine stains is laser. A particular
type of laser known as a flash lamp, pumped, pulsed dye
laser is used for treating these birthmarks. The laser produces
a narrow, extremely intense beam of high-energy yellow light.
The yellow light is preferentially absorbed by red blood
vessels; very localised heat is produced which destroys
the abnormal blood vessels. To treat a PWS numerous shots
of yellow light are fired at the skin. Each laser shot produces
a short sting in the skin, like being flicked with a rubber
band. The laser treatment can be carried out without anaesthesia;
but babies and young children do not tolerate the associated
discomfort and general anaesthesia is usually recommended;
in older children the skin can be “numbed” with
a special anaesthetic cream (EMLA).
The laser device is housed in a machine 2-3 feet high and
has a mechanical arm with a pen-shaped attachment on the
end from which the laser light is emitted. The doctor, any
attendants and the patient have to wear protective glasses
to protect the eyes from stray laser light. When the laser
is operated there is a clicking or cracking noise. The laser
light is applied to the area being treated in a series of
short pulses.
Laser treatment is usually carried out as a day-case procedure.
After the procedure the PWS looks much worse. The laser
shots can be seen as a collection of deep purple spots,
resembling a bruise. This appearance should fade over two
weeks leaving the PWS lighter than before. The child may
complain of some discomfort after the laser treatment; this
can be alleviated by paracetomal syrup and the application
of cool-packs.
Outcome
On average, 6 treatments are required to have a significant
effect on, or to clear, a PWS birthmark. A test-patch is
usually performed before the whole lesion is treated. Some
PWS show no response to laser treatment and thus is usually
evident after, say, three treatments.
There appear to be no long-term side effects of laser treatment.
Occasionally the skin may blister or scab; this is only
temporary.
