Ear issue

So Alex (older kitty) has always had an itchiness to his ears. He always wants his ears scratched, like a drug. I took him to the doctor man once and he was prescribed a cream that was suppose to treat outer ear bacterial infections. I never noticed it made a difference. This was about a year ago. Now, I have just noticed on his left ear on the top inside and outside is something scaly. I'm not sure what rot looks like but it's definitely something. I feel extremely guilty because I'm not 100% sure when this actually started building up.

I've attached some photos. I have feeling this is something fairly common but I can't find any other specific posts online with the same type of photos. Can anyone help me diagnose? Is there anything I can pick up from the store? Or can I have my vet call something in without him being seen? Have a feeling I'm going to have to take him in. Just takes forever to get an appt with my vet.

Anyhow. All advice/help/recommendations appreciated!

Yeah, a lot of the photos online for different conditions look so similar to that it's hard to say. A few years back....late summer.. I took my cat in for his shots and I remember the vet mentioning how many cats had been in that summer with what ended up as being allergies. I'm just not sure how you could know for sure what that is on your cats ear without having a professional check it out. If it was bacterial the first time maybe it's the same thing...and he needs stronger cream....or a different cream. Hopefully somebody with more knowledge will chime in on this...My cat's never been treated for skin conditions.....so I don't have much experience with it.....

Thank you very much for your response. My guess is he needs a stronger cream also.

Well I got an appt for next week. My vet can never get us in right away. I cleaned with antibacterial soap and water for now. Just a boost- anyone else seen this particular issue before or have any suggestions? Thank you.