Help!! What's happening to my fish?

[GCW]

Hi there, came home today to see my blue tang like this, it has been suffering from white spot for a while but the white spot has subsided but can't seem to be removed. The mouth however, was fine till today. Am quite worried and any help regarding what's wrong with the fish is greatly appreciated! Thanks

 

[scooter31707]

Looks like that by be HLLE.

 

[JUNBUG361]

Its either velvet or some type disease. How long have you had the hippo?