Blue blisters in ears
I had two cats with navy blue growths in their ears. One died two days ago of something the vet had diagnosed only as neurological. I'd brought her in because of lethergy and loss of appetite. After some VERY expensive blood testing, he said she had an elevated white cell count, indicating some kind of infection, and put her on antibiotics, first one, then another. Then she had a seizure...whereupon the "neurological" diagnosis. He had not seen these blister-looking growths in ears before, and I wonder what they are...if anyone has seen anything similar. They were numerous: most, approximately 3 mm in length, and usually of an oval shape. The skin around them was also stained blue in patches. I put nothing in her ears, and they did not appear to itch, though she would shake them if I touched them. These growths occurred only on the inside of the ears, not the outside...and nowhere else on her body.
Her best buddy has the same thing in only one of his ears. He has had problems with a dark discharge from one of his ears from time to time. I treat him for this when it crops up, using first an ear cleanser, then an antibiotic / steroid preparation designed specifically for ears.
Both of these cats have white background fur...but they have been totally indoors since they were kittens, so sun damage is very unlikely. My deceased Pretty Girl was white with red tabby patches. Fat Schyler is a cream tabby colorpoint. Pretty Girl was just turned 15, and Schyler is about two years older.