Hi. You can either go to a plastic surgeon or dermatologist, either one would do good work. Try taking a look at the vascular birthmark foundation website. they have a list of physicians who treat birthmarks. it's : www. birthmark. org
good luck. :)
You might want to see a plastic surgeon. I don't know where you live but I know one in LA or Beverly Hills. My friend went to him and she was really happy with his work.