Hi. I have a child with pws and sws. As far as the blebs you are describing from everything I've learned that is cobblestoning. There is a support group just for pws the link is www.birthmarks.com
There is a lot of adults on there and parents of child with pws. The site has just been update and you have a place to put your personal web page on there. Several people already have so you might find that intreating. I'm so glad you found us here. I hope you have a wonderful day.