When this popped up again, I thought it worth commenting. I've noticed that my dermatographia has significantly improved since my last post on this thread. I'm not exactly sure when it happened, other than I started noticing I could scratch my back without triggering an all-out raging attack, which is what used to happen.
I haven't been doing anything for it specifically, but wondered if maybe it IS a component of Lyme, and my treatment has allowed it to mostly resolve. Who knows though? It might kick back in again at any moment. Anyway, for those who are trying to figure this out, it's just another piece of the puzzle.