I have a toenaill that's been "weird" for a few years now; I have no idea if it could be some strange Lyme-thing or not, but the timing is right.
While running on a blacktop parking lot barefoot(don't ask!) I ripped the nail almost completely off my toe next to the big toe. It fell off, & regrew a few mos. later, but it has never been the same--it's thick now & seems very calloused, though brittle, like I could pull it off fairly easily. It's not bothersome, but it does make me wonder...