Fiji Devil losing skin?

If I had a camera, this would be a whole lot easier, but here goes... My Fiji devil seems to have either become injured, or something is removing the outer layer of skin, perhaps the scales. He has a spot on the side that is completely void of his striking blue color, but the area isn't fuzzy or covered so to say. It literally looks like the skin is just gone! To make matters worse, the area seems to be getting larger as time goes by. Behavior wise, he seems fine, eats like normal and spends his day chasing the other fish around the tank. Any ideas what this may be?

BTW, there doesn't appear to be any redness or swelling in the area that might indicate an infection. [smiley=uhoh.gif]