Bumps on ears

First it was bumps on his nose, now one of our cats has bumps on his ears.  They have been there about a month or so. But they are all overthe top part of his ear. And theres fur missing. We just ordered Frontline spray last month. Our vet said mosqitos could be the problem of the bumps on the nose, so i am guessing the same thing here. The frontline says every 30 days. Would it be okay to do it again in 2 weeks? Oh, and the bumps are still on his nose, they dont want to go away. I put something like neosporin on it every now and then. When i dont, they can get worse. Is there anything else i can do for this?

Can you post a picture?

The bumps are almost not visible. They are on both ears.

Looks like feline acne. My cat has it. Wash with chlorohexidine soap daily. Doesn't hurt them.

How about blue dawn?

My cat has the same thing-he gets this every june-July for a few weeks, he scratches the heck out of his ears as well. My vet thinks it's allergies, because it eventually goes away and happens the same time every year.

It appears as if it is miliary dermititis.  One of my former cats broke out due to a switch in food.  We were given prednisone, but were too afraid to administer it.  It eventually went away on its own.