I have a rather large, patchy, flat pink PWS on my right leg. Problem is that the stain changes colour depending on the temperature and whether I am lying down or not. When I lie down it turns really pale that the doctor can't even see where the stain is. When I stand up the redness comes back. Especially with the added cooling mechanism of V-beam my doctor is using, the stain becomes so pale that I end up getting only a few shots even though half of my leg is covered by the stain.What can I do?