Spot on blue tang

[gopalka]

Hi all. I’ve noticed this spot show up on my blue tang. He’s been in quarantine with copper since 11/18. Any ideas what this spot is? Also appears to be another one on his bottom but I couldn’t get a good picture. Suggestions for possible medications?

 

[JGT]

Can’t tell from pic. Doesn’t appear to be white so prob not ich. Could just be an abrasion but pic is too far away/unclear to tell.