What To Do For A Cat With Allergies?

My cat has a lot of allergies and she is a very "licky" cat. Over the years she has licked off all the hair on her belly and inside of her back legs. She is happy, gets a lot of attention and 'entertainment'. Her licking increases during summer....she licks and bites at her bottom nipples. Topical solutions don't work because anytime I put something on her she increases her licking of the area to remove whatever I put on. Any other solutions....I would rather not to oral medications. I tried allergy shots for ~ year....but no difference.