Tiny White Bumps on a Cat's Head?

My cat has had ear mites recently and had to have surgery to remedy the problem from these mites. It created a huge hematoma that draining fix. He has been treated for these mites by a vet. He gets very tiny bumps up around his head and shoulder area. These aren't bumps on the skin, they are located in the hair down by the skin so I can scrap them away with my nail.

He doesn't seem to be bothered a bit when I do this (many times not even noticing I have done it). I have tried looking at the bumps and it looks like a tiny bit of white scab attached to the hair, not a real bump at all. What could be causing this? He is not shaking or scratching his head. I can't see inside his problem ear since the ear flap is almost entirely closed from the surgery. (The vet said this happens in some of those surgeries and although strange looking, it is not a problem.) Anyone ever heard of these bumps? What could it be?

By Joan Vance from Cedar Bluff, VA