Port wine stain on scalp

The risk of hair loss from laser is largely related to the color of the hair.  If the hair is brown or black, then there is a risk of the laser targeting the melanin in the hair.  If the hair is blond or gray, then the risk of hair loss after laser is much lower.  Pulsed dye laser is less likely to cause hair loss than IPL.  You should see a dermatologist who has extensive experience treating port wine stains with pulsed dye laser.

I would recommend that you see a dermatologist who is an expert in treating port wine stains with the pulsed dye laser.

Treating areas that have hair can result in patchy hair loss no matter what. We always warn people for instance who get FotoFacial/IPL etc. on the face, that they will have some patchy hair loss in the beard and upper lip area. If they don't want this, those areas cannot be treated. So yes, if you want to treat your port wine stain on your scalp and neck you could definitely get some hair loss in those treated areas. You'll need to decide what's going to be the lesser of two evils in this case.