Really sick Lotl, infection?

Hey all, unfortunately I had to leave my Axolotl with my father for the week and something terrible has happened to him, and I believe it is directly related to a tank cleaning that occurred before I left. My father noticed that some of his skin had come off and immediately removed him to smaller tank with clean water, his skin got better, I assumed it was something funky in his normal tank waited 24 hours then had my father attempt to reintroduce him into his regular step but, that was a horrible idea and he got really messed up. He is leucisc but I from the pictures I received he is yellowing and many of his blood vessels have become visible, his gills have reduced in size and in general looks like death. I have honestly no idea how to help this guy, once again he was removed from his tank and is in a nursing tank where he seems to be acting somewhat normally but continues to look like death.

http://i.imgur.com/QCeYliM.jpg

thank you for the help

That axolotl looks ammonia burnt, you may have blown your cycle, get the water tested and post the results, leave the axolotl in the bucket with daily water changes till you find out whats wrong, keep him cool.