Sick naso

[Jcj0033]

So I bought a naso tang about a week ago on 6/8/17 and he wasn't eating but I bought him anyway the store had only had him a couple of days so I wasn't to worried about that. When I took him home he was really shy which is normal but the next day it look like he had a few scratches on him. Every day the scratches looked to get worse now I'm thinking he has some kind of skin disease or parasite. I did not quarantine him because I have had horrible luck with my qt tank. All of my parameters are good so im wondering should I be worried about this fish, should I get him out, and I really just need to know what the heck this is on his skin. Here are some pics of the naso if anyone has a clue on what it could be please let me know. I didn't think it's ich or velvet but I could be wrong

[Sniperhank]

Looks like he got in a tussle with some other tangs to me. If things are stable and stress free it should recover and start eating. Make sure there are enough greens available for it to graze on.