Tang Disease

[onad75]

I have this 3" purple tang and he is in my 50g tank with a pair of clown fish, he is eating well but some how he got this white spot on his face and to his body, what kind of disease is this and how can i get rid of this?
thanks for your help.

 

[Travis L. Stevens]

He has Head and Lateral Line Erosion (HLLE)

 

[Steven Pro]

I concur. See here to read about this ailment,
http://www.reefkeeping.com/issues/2005-06/sp/index.php