The Pediatrician, should send you to a Dermatologist specialist.
Where does your son have it on his face?
This also impacts the status of it... per blood vessels etc., that it can be on. Because it can be connected to the circulatory system/vessels and be filled with blood. For example.
My Husband had one on his forehead as a child.
When he was a child, they did surgery on it and removed it.
BUT... a Specialist Surgeon did it. BECAUSE, the surgeon had to KNOW... how to remove it, so that as he got older and the removed portion healed, that it did not 'pull' the skin in an awkward way, for example. He had to also have a small skin graft on it, so that there would be enough skin, to stretch over it and heal without pulling the skin in a weird way.
Although nowadays, there are probably more 'modern' ways of treating it or it goes away on its own.
Again, the Ped should be sending you to a Specialist. Ultimately.