For decades I had red spots, like a bad acne mostly on the back of my head. When I first shaved my head, the condition cleared up in a few days. As long as I kept my head shaved, no more problem. Whenever I attempted to grow my hair back, the spots came back. I went to a dermatologist, and she gave my a prescription for a shampoo and a lotion. Neither one worked. When she wanted me to take long term antibiotics, I said no! I think it's a form of folliculitis.
So when I went back to my family doctor, I told him about the dermatologist, and not wanting to take long term antibiotics. His advice was, then just keep your head shaved, it looks good on you!
I'm not sure you have the same issue, so shaving might work.