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A capillary malformation (sometimes called ‘port wine stain’), is the sort of red mark on the skin which most people think of as a birthmark. They vary in size from small to quite large. Small capillary malformations are common. If they are not on the face or another visible area such as the hand, they may not be a problem. Most capillary malformations are flat during childhood. They often become darker and thicker during adult life.
As with other birthmarks, we believe that capillary malformations are due to a ‘somatic mutation’ or an error of cell copying of DNA code during development. Recently it has been suggested that nearly all capillary malformations are due to the same error in a gene called GNAQ. This error of development occurs by chance and is not caused by any action of the mother or father.
Laser is the most effective treatment for capillary malformation. There are different lasers available and some lasers may be more effective in some birthmarks than others. Often laser specialists will try a ‘test patch’ before proceeding to full treatment. Multiple treatments are often required. The results are variable and many capillary malformations only respond partially or not at all. We do not know why this is. It is not known if laser is more effective if started earlier. Often, one or two treatments can be given before three months of age without the need for a general anaesthetic. Further treatments usually require a general anaesthetic and are often started in the year before school. Even if good clearance is achieved, there may be recurrence in subsequent years that warrants further laser treatment.
Some children who have a large capillary malformation around the eye have a corresponding swelling on the surface of the brain which can cause epilepsy and affect development. Not all children with a capillary malformation on the face have Sturge-Weber syndrome. An MRI scan can usually (but not always) detect the brain component if it is present. There is no specific treatment available for brain involvement and many doctors and parents choose not to perform an MRI in this situation. This is something parents should discuss with their treating doctor.
If a capillary malformation is on the eyelid, the child should see an eye doctor to test for glaucoma which can cause vision loss. Sturge-Weber syndrome is not associated with facial haemangiomas.