Crusty ears, head, spot on nose.. Mange? What else?

My cat, Jack, has crusty ears. The insides of his ears are clean. The edges along the outside and inside and about an inch down his ear on the inside are red, crusty and itchy. The hair along the back of his ears on the edges is gone. He is also scabby on his head, specifically in that area between his eye ad ear, but he has a few on his head too. He now also has a new red spot, about pea sized, above his nose. From my research online, it looks like mange, but I also wonder if it could be some type of allergy or autoimmune problem.
He has been to the vet twice. At the first visit he was diagnosed with ear mites. He was treated with 3 months of revolution. He cleared up slightly, but not completely. I took him back to the vet when they got worse. Their were no mites or larvae inside his ears this time, they were spotless, but the vet said to continue with the Revolution. I'm 2 months into that now and the problem still exists.
The second time he went to the vet he was also given a cortisone shot. His ears and head cleared up completely for about 4 weeks. If this IS mange, would the steroid shot have cleared him up? I'm thinking no since it would lower his immune system and probably make the mange mites attack even more, but I wanted to see what others thought.

He has also developed a spot around his nipple. Red, raw, itchy. That was why the vet gave him the steroid shot at the second visit. It cleared up too, but is now back with another one forming above it.

He eats Blue Buffalo food for sensitive stomachs. Also, not sure if it's relevant, but he has always been a vomiter. He throws his food up at least once a day about 4-5 days a week. He's 2.5 years old and has been like that since I got him as a kitten. He has been dewormed and all that, and I've tried him on all kinds of different foods, good brands and even crap brands, wet and dry. I chalked it up to him eating too fast. He does eat fast sometimes, but not always when he throws up.

Anyone have any insight as to what might be wrong with him? I'm going to take him back to the vet soon, possibly to a different vet for a second opinion. Just wanted to see what I might be able to find out online before then.

Oh, also, when his symptoms get real bad and itchy I put cortisone cream on his ears and that also helps him clear up if I do it daily for a few days in a row.

Has your vet tested him for ringworm?

About the vomit - is it right after he eats, undigested food? can you see pieces of the food in it? Whole kibbles? If so, that is regurgitating, usually due to eating too fast - can be resolved quickly. Can also be due to hairball problems and blockage, if it becomes too constant - i.e. regurgitates all he eats...

His vomit is definitely regurgitated food. It's never anything but whole kibbles. He must just be in a big hurry to eat all the time. He's a piglet!

He hasn't been tested for ringworm, but I can pretty confidently say that it isn't ringworm. I unfortunately had to learn all about ringworm in the worst ways. When I got him, originally as a foster, he unknowingly came with ringworm (didn't show up til about a week later). He gave it to my other foster kitten, my dog, my friend, and me. On my chin! And 2 spots on my arm, one of my hip, and one on my leg. It was a nightmare that took several months to get rid of completely.

PS - All of your kitties on your signature are gorgeous!