Gourami with small "sore"

[Snake Eyez]

I have a Dwarf red Gourami that I've recently noticed a small "sore" near his mouth. It's seems to be shaped outward instead of inward like a ulcer. His behavior hasn't changed and he still eats just like before. No other fish seem to be affected by anything similar.

Any suggestions or ideas?

 

[Velvet AciD]

I'd treat it with an antibiotic of sorts just to be safe. Is it darker than the rest of the body or is it noticeably something that shouldn't be there?

 

[Snake Eyez]

Can easily tell that is shouldn't be there. No other changes anywhere else on the body and no changes in mood or behavior.