My snakeskin has always healed and bounced back for me. She has never had ICK though (knocking on wood). I do a 50%
PWC ever week and vacuum. How often are you changing water?
Did the white spots look like single specks of salt? Is this fish being bullied or damaged from another fish in the tank?
Looks like he's sitting at the top. Snakeskins are generally all over the tank.
Sounds like you may have to treat the fish. Can you get a better picture?