Bite Mark On My Apistogramma Cacatuoides Orange Flash

Hey again guys.  I have an Orange Flash that was bitten some time ago by one of the other fish.  For a while I didn't give it much thought because it seemed to be healing fine and was almost gone.  Recently, I noticed that the bite mark was not only more obvious than it had been, it now looks like it might be a little irritated.  Kinda looks rough and it seems to be a little more "bubbly" looking. I'll try to add a picture later if I can get him to sit still long enough.  

Any idea on this?  Is there anything I can do to help him heal?  He's one of my favorite fish, and I'd hate to lose him after he had seemed to be doing so well in my tank.

If I notice a lesion on one of my dwarf cichlids and it doesn't heal right away I add aquarium salt. If it's really bad perhaps add an anti bacterial med.

i usually lean towards melafix when i have a fish with an issue, i always use 10% of the reccomended dose if that (half a capful for my 125g) it seems to help them out almost overnight, kinda like neosporen for fish. make sure to do water changes to get it outta there as it will cause a strange minty odor, and bubble in the tank pretty good (like surface bubble action) GL to ya. hope it all pans out

Thanks guys. I bought some Melafix to try, hope it goes well!