Swollen around the ear, what can it be?

I noticed this Sunday at my cats ear, can someone guess or know what it can be?
It is like a ring and its a bit swollen, I put some antibiotics on it now because he scratched himself and a bit of blood came out.
Once in a while he scratches himself with the back paws around the ears, I try to keep his nails short, but it does happen, this one tho is a bit different. I looked at it today and it had something on it, like a needle poked him and I also think it might be itching him sometimes. I have an appointment to the vet next week if he doesn't improve. Its red because, as I said he scratched himself. Otherwise everything is normal with him.
What cat that be?

Ouch, looks red and raw. It's hard to tell what this is because most of the usual suspects (ear mites, ringworm) are microscopic and the vet needs to take a sample and look at it under a microscope. These things rarely clear up on their own because the cat keeps scratching. 

Let us know what the vet says.