Hi. My son is 12 years old and has PWS on his left hand and arm. The PWS is most dense on his hand. We were told when he was born that it was fine to leave treatment until he was older and consequently he only started last year. He had a test patch of laser done on the inside of his lower arm at Great Ormond Street Hospital in London. They used local anaesthetic to numb it first and he coped brilliantly and didn't feel any pain until the following day - it stang and needed emolient cream. They went ahead with his first proper treatment in November and did 47 shots on the inside and outside of his lower arm. They have not treated his hand as the surgeon said this is the most painful area to treat as the digits swell and become very painful - we have been told that they may never treat his hand. The underside of my son's arm has healed very well but, unfortunately, the outside scabbed after four days (even though we meticulously applied cream as instructed). These scabs have left areas of hypo pigmentation. We returned to GOSH today and were told that they will not continue treatment until pigmentation has come back into the areas - where they were once red blots on his olive skin, they are now white blots! We have been asked to return in a year, but not been given any reassurance that the pigmentation will come back. It is very disappointing but I guess one of the risks. Hope this has been of some help to you. Our surgeon at Great Ormond Street Hospital is Dr Samira Syed.