White blotches appeared on blue gourami- any ideas?

Hi all,
My blue gourami has been quiet for a little while. It appeared to improve and then developed these white blotches across it's back- seem to only have just appeared. It is currently swimming and eating fairly normally but a little quiet. I'm going to speak to someone tomorrow but any initial ideas anyone has this evening would be really appreciated- thanks in advance. Other fish in tank appear fine. Rapid test strip results pretty normal for the tank too. I've had the fish about 2 years so it's adapted to the tank

How long has it had the white patches for?

What other fish are in the tank?

Have you added anything to the tank in the 2 weeks before the fish started acting unusual or developed the spots?

It looks like physical wounds but if there aren't any fish in the tank that attack it then it could be the Gourami Iridovirus.

Hi Colin, thanks for your reply. Nothing added for months. Only suspects for attack are 4 Colombian tetras. The rest are either bottom dwellers or extremely quiet little tetras

Columbian tetras usually go after the fins rather than bite pieces out of the back. If you have a spare tank you could isolate it but that won't make much difference if it's the virus.

I would do a big (50-75%) water change and gravel clean the substrate every day or every couple of days for a few weeks. This will dilute anything in the water that might be stressing the fish and hopefully help it recover. You should also clean the filter if it hasn't been done in the last 2 weeks.

Maybe raise the temperature a few degrees if it's below 26C.

Feed the fish a varied diet that includes dry, frozen and live foods and feed it a few times each day. The extra food might help boost its immune system and help.

Any possibility of the fish swimming into something then struggling to get out. I agree with @Colin_T those look like injuries.