Patchy fur on cat's ears

Hello, vets and techs 3-4y/o spayed female cat (indoor/outdoor) Two days ago I noticed this patchy fur on my cat's left ear. It looks and feels a little crusty, and the edge of her ear appears a little nicked up. My first guess is that she got into a scrap with another animal, but I'd like to rule anything else out that might need attention. She's up to date on all vaccines as far as I know. It's not as red in person as it looks in the photos. The third image shows her right ear, which does also appear somewhat patchy (she started life as a feral gal, so the neighboring county bumpkins did a catch/clip/release on her before we found her) Thanks for any help you can offer!

Follow up observations: So this may or may not be related, but she's yelling for food much more than usual. Like really excessive meowing sometimes. Ordinarily she's very food motivated, but this is a marked behavioral change. Maybe I'm misinterpreting what's going on, though, and she's actually expressing discomfort. She isn't scratching or grooming more than usual, though.

  Hello - my first thought, when we were talking about ears, was a little mite called Demodex.  Demodex are underdiagnosed in cats because a lot of people attribute them to 'old age'.  They are best looked at under a microscope and cause baldness and raggy ears. Then i went on to read the rest of your post; your cat is suddenly eating excessively.  This often implies systemic illness eg hyperthyroidism, diabetes, liver disease, even cancer.  It is a serious symptom and cats doing this need to see a vet ASAP Incidentally, systemic diseases such as the ones I listed often take up a lot of the body's resources to fight.   Its not quite accurate, but if you think of the white blood cells that protect the skin against parasites, as being too stretched or too busy to do their job properly, this may explain why a lot of cats with systemic illness then start to get raggy ears. Other explanations for the ears may include (itchy) other kinds of mange, otisis externa, skin cancer.  However, it is the excessive eating that concerns me most at the moment.  Please do see your vet.

If you search for 'demodex' in the blog, you will find out more about that;  eating excessively especially in the face of weight loss, is known as polyphagia.