Sick Yellow Tang

I was wondering if anyone had any suggestions for me, I have a 75 Gl FOWLR tank with a 3 inch Yellow Tang and a 3 inch Niger Trigger. They have been living together for about 1 month and they seem to live fine together although the Tang doesn't like when the Trigger goes near its cave and forces him out with his rear fins. The tang has started to show signs of reddish blotches on its sides and a little in its top fin. I imagine that is Blood but he eats fine. I have been feeding him Lettuce, Nori, and Flakes all soaked in Garlic and Selcon. Is there any meds I can try treating him with ?

Thanks