Sore on Gourami's head

[Salty Fishes]

Today I noticed that my opaline gourami had what looked like a sore on her head. Other than this, she is acting very normal, swimming around and eating. It almost looks like one of my other fish attacked her, which is a possibility. However, it seems weird that they would attack the top of her head. Also, my gourami is the "queen" of the tank.

I tried to take pictures of this to show, but they all turned out blurry. I'm going to post them anyway.

I've had this gourami for nearly two months now. The tiger barbs and yo-yo loaches have been in with her for about 3 weeks. I've never seen any fish even attempt to go after her. She really does boss them around. That's why I suspect that this might be a disease. I haven't checked my water parameters yet but I will soon. I suspect that they're fine though.

Can anyone help??

 

[Salty Fishes]

Another picture.

 

[Salty Fishes]

Last picture. These do make the spot look almost redder than it is. Maybe I'm just overreacting.

 

[Lotus]

I would probably add some Melafix (in a hospital tank, if you have one), and wait. If it's an injury, it should start clearing up in a day or two.

The other possibility is that it's some kind of bacterial infection. If the sore gets larger or fluff of some kind around the edges, then it's a bacterial infection, and you will need to get some antibiotics.