Hillstream loach discoloration

Hello I’ve had 4 Hillstream loaches for around 3 months now in my planted tank and everything was good. Recently one of them worked its way out through which I guess is by crawling up the intake or output tubing of the fluval 207 canister filter I have on it. He ended up on top of the lid and I was able to save him but when I grabbed him he felt very dry and sticky. I suppose he was out of the tank for some minutes since he was dry on the top. Once I dropped him back in the tank, he immediately swam and started doing his normal activities. This happens around 4 days ago. I don’t remember exactly which one it was but on one of them there is like a white discolored stripe it almost looks as if it’s peeling or something on its back. I’ve looked at the other 3 loaches and nothing looks wrong on them. This one with the white stripes is acting normal, he eats and sticks on the glass and even eats algae off the driftwood in the tank. I don’t know if it’s an illness or if it’s like a wound (supposing this is the one that got out) that is healing? I will try and get more pictures but for now it’s the best I could get of him.