Vascular birthmarks are caused by an abnormal development of the blood vessels in the skin, which is why they are usually a deep red colour. The colour depends on how deep the blood vessels are, with the deepest appearing blue rather than red. They can be flat or raised, and mostly appear on the head and neck, although they can develop anywhere, even inside the body.
There are two types of vascular birthmark:
This type of birthmark includes what is known as the strawberry mark. It can first appear as a small flat red mark, but it will grow, rapidly at first and then more slowly. They can become quite bulky, and although some can fade with time, the mark can remain and can stretch the skin.
This condition can result in a mixture of vessels, veins or arteries being too close to the skin, and in too high concentration. Port wine stains are an example of this type of birthmark. They tend to be permanent, and can also be sensitive to changes in hormones.
Laser treatment is the most effective form of port wine stains removal, and can cause the mark to fade without damaging the surrounding tissue.