I know this is an old thread but like several others here I am guessing a spider bite-(actually they don't bite they fang). I got zinged on the nose while I slept a week ago and while I did not look that bad my nose swelled up and was uncomfortable for about a week, the tissue was bumpy like your pictures. Our crew loves to try to herd spiders that scurry across the rug and they try to smell them and I can just imagine one "biting"a nose on a curious Sheltie.. glad he recovered.