I Have Had An Ongoing Problem For Over 14 Years.

I have had an ongoing problem for over 14 years. It started with small bubble like spots all over my scalp that were filled with a clear licquid when broken. Now for the past 2 years I have a 3 to 4 inch by 1 inch patch on both sides of my head just above and forward of my ears that thicken with a white coating that seems and feel like plastic. I have painfully scrapped this coating off only to see it back within a 24 hour period. If I do not scrape it off it gets thicker and thicker. I have tried all kinds of creams and shampoos without any helping my condition. The spot that is covered with this plastic type coating seems to go up a vein that follows up my head. this vein seems to be filled with fluid if I press on it. I have seen a skin specialist a few times when I had the small sores on my head and was given an antibiotic which did help.
A biopsey was also taken an came back negative.
Thanks
Harry