Please help ID grey spots on Naso

[tmulrney]

From one day to the next these discolored areas have shown up on one side of my Naso Tang. They look to be grey-brown and flat. The spots are much larger than a pepper so I don't think it's Black Ich.
The fish is feeding in the usual manner. Any help is greatly appreciated.

 

[b0bab0ey]

Tangs are known for having splotches (usually first thing in the morning then they go away) but they're usually larger than that. So my first guess would be a coral or anemone sting. Does your tang sleep near an anemone or an LPS with sweepers that could sting him at night? If it gets worse or spreads my second guess would be a bacterial infection which would require QT & antibiotics (like those found in Furan-2).

 

[tmulrney]

I do have an anemone. I'll keep an eye on spots. Thank you

 

[tmulrney]

Bump