Sick Or Injured Dwarf Neon Rainbowfish

I recently noticed one of my Dwarf Neon Rainbowfish had a lump on its body, very close to its gills and noticed scales were missing of it.

I've looked on the internet to try and see whether it might be a disease and couldn't find anything that looked like it.

So now I'm not sure if it might have just injured itself or one of the other fish has been picking on it.

Just a bit of tank info

Current stock:

5 red phantom tetra
3 black phanton tetra
1 honey gourami
1 german ram cichlid
6 dwarf neon rainbow fish

200 litres (43 gallons) heavily planted tank

Nitrite: 0
Amonia: 0
Nitrate: 20 ppm

Any help would be appreciated as i'm not sure how to treat this fish

 

I cannot judge from the photos, can you get clearer ones?

 

I wil try to get clearer one, but they are quite difficult to get pictures of.

 

Here is another picture that's a bit clearer, if anyone has any ideas of cause?

 

I have added another pictures that's as clear as I could get, if you could have another look to see if you could possibly identify cause.