Bi-Color Angel Sick?

[DotAlbo]

I have 2 Bi-Color Angels in my 6x2x2 and i recently removed them into a 6x1.5x1.5 tank. The first day they got in there they started fighting but not severe so i left them there and after 2 days they are fine but i noticed some white patch on the top of the head of both angels and i didnt care too much because i thought its the result of the fight and they are rubbing them self on the rubble. Two days after the patch got bigger and on one the white patch extend from the head to the tail.

Is this result of fighting or is it a disease? I have anthias and wrasse in there should i remove them?

thanks,