The lump didn't hurt, but it was quite hard on the scalp. It was not a part of my skin because the skin moved over the lump when I rubbed it. The lump was there for several weeks and then slowly went away. I had another PRP treatment recently and the lump is back in the same place but smaller. Immediately after my last PRP treatment I had a score spot on my forehead, which soon developed into a lump as well. Neither of these hurt. Could these be from PRP? I haven't hurt my head otherwise.