Mystery Mark On My Catfish

i have a Featherfin Synodontis catfish and a day ago i noticed he has a scratch kind of mark near his top fin. he doesnt seem to be acting any different and he still eats as normal but im concerned it might affect him in time.
he does like to hide in small spaces and he has a cave in a piece of driftwood so im hoping he just scratched himself on that and it will heal over time.
he shares a tank with a large angel fish and lots of tetra's and smaller fish but they all get along very well so i dont think any of them could of hurt him.
can anyone help?

It looks like it may have scratchee don a rock or any other sharp objuct. Dont worry, it will be fine, he will heal up fast.

Does the wound look infected.
Usually for wounds melafix, But I would only add half dose as some fish don't tolerate the full dose.
Is it possible to issolate him for treatment.

he looks a beauty!

As said, with clean water and a drop or two of melafix he should heal quite quickly

He is a beauty davo.

yeah i can isolate him if need be. what is this melafix stuff? ive never even heard of it hahaha
i dont think it looks infected.. but i've never had this problem with any fish before so i dont really know what an infection looks like on a fish anyway haha. its been a few days now and this mark still looks the same but he doesnt seem to be unhappy.

great news!
its been 5 days now and the mark is almost completely gone away! yay!
i didnt use anything i just let him heal himself and i guess it worked.

Bless Him.
Glad he back to full health. Well Done.