I've heard of others having this before.
This article on bartonella mentions "crusty scalp."
https://www.gordonmedical.com/unravelling-complex-chronic-illness/bartonella-like-organisms-blo-consideration-signs-and-symptoms/. Some people get head sores.
I had dandruff in the outer third of my eyebrows, base of eyelashes, and temple area but not my head. I'm not sure if it was from bart or mold or something else. It went away after I left my moldy house 2 years ago.