I have the same thing. I used to have a scaling dry scalp and then a few years ago, it changed to scabs. The scaling stuff went away. I think mine is related to the autoimmune/hypothyroid problem that I have. (Hashimoto's Disease) It is known to affect the skin of people that have [it in lots of different ways,..but not a given).
I once saw a person with autoimmune disease on here asking if others [w/ AI disease] had such a thing. There were quite a few that did. Do a search on this board for scalp/scabs/autoimmune. Not to say that you have AI, but it does seem related for some of us. I haven't really tried that hard [yet] to work on mine. [haven't seen a Dr. yet...mine [I would say] is moderately bad. I hate it... but I feel so well compared to a couple of years ago, that it's hard to get upset over this.
I will eventually see a dermo Dr. and work on getting this thing under control. My hair looks fine tho. I just need to QUIT picking them off!
My husband gets so mad at me! (I told him if they were on his scalp, he's be picking them too)