Hi and welcome!
The first thing to do is to see the physician and find out what they know about vascular birthmarks and if they are willing to refer you. I think you're right to be proactive, but remember to ask lots of questions. It is OK if you ask things like, "how many of these have you treated and what were the outcomes?" and "are you familiar with new medications that are being used to treat these?"
Ask lots of questions and make sure you get the answers! Take in a list of questions if you have to, so you remember.
Let us know how things go!