Ear tips tend to bleed profusely
Maggie and Mongo were playing in the yard one day and Maggie must have nipped the tip of Mongo's ear, but we didn't see it happen. When we let them in the house we panicked. Mongo was covered with blood (because he had shaken his head) he had blood all over. We had to firgure out where it was coming from. It was the very tip of his ear.
I kept putting neosporin on it and found that the bandaids used on knuckles stayed on the best. Had to change it about twice a day. Here's a pic of Mongo modelling his bandage:
As far as allergies, high doses of fish oil may be beneficial. See this article:
Fish Oil For Dogs
That, or a raw diet