Thank you guys for responding, it probably is a splinter of some kind.
would it be best to give him a betadine-water bath soak, or to rub the spot with a rag that has a teensy bit of betadine on it?
anyway, my temps are:
89-91 hot side elevated, I use a CHE as overhead heat. it's probably 82-85 on the ground surface level.
75-80 cool side, my house has poor cold temp management so it can get a little low at night. I had to opt for overhead heat because a heat mat wasn't keeping them above 69 at night.
I use sphagnum moss + cocohusk for his substrate. Mist occasionally.
I hadn't really given him anything new besides a hide and his cork round, which both he fits in snuggly.