Mine is doing the same. Doesn't feel like sandpaper but raised spine, loose skin. It hasn't eaten in like a month and it is very small. The albino i have about the same age but is filled out and more active. Im trying not to mess with either and will try to feed them again on Sunday. I'm trying not to worry cause I've read so much about them being picky. Hopefully they eat next week so i can start handling them.