I had/have something similar off and on.
I get this intense scalp itching one day, then the next my head will be all broken out in sores, like ingrown hairs or something.
I talked to my LLMD, who's also a OB/GYN, she told me is was probably yeast and had me start Nizorel Shampoo. It's at Costco. I use it every 3 days or so, and haven't had any more problems.
Around the same time frame I also got a vaginal yeast infection, so I thought. The doc started me on vag acidopholis suppositories and also gave tea tree oil suppositories to use periodically. She said that with Lyme patients, we usually will get vag bacteria before yeast. So I'm asssuming it would probably be good to use a tea tree shampoo too.
Oh, now I'm itching my head again....LOL.