It is difficult, if not impossible, to diagnose a problem like this online, because you need a visual examination, along with perhaps some blood work and scalp biopsies, depending on the examination.
There can be many causes, and combinations of causes, for your problem:
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The best thing to do is to contact a dermatologist. They will be the best to diagnose and treat. If it takes you a while to get an appointment, start with your family physician for some help.
I am sorry that I couldn't give you a definitive cause for this, but any skin problems are best taken care of with a visual examination to start off with, followed by possible testing.
If you have any other questions or concerns, please don't hesitate to let me know.
Best wishes to you,