Allergy/Skin Issue

I posted last month when Sadie had open sores all over her body, she has since started healing. We had biopses done with results ruling out cancer, auto immune or other terminal illness. My vet's diagnosis is allergies. He said he would refer us to Shands for allergy testing, but that she could be allergic to any and everything. We live north of Tampa/south of Gainesville. Many people I have talked to about Sadie, say they or someone they know has dogs with allergies/skin issues. We have ruled out food allergies, took away all table food except baked chicken strips and Merrick bison/sweet potatoe dry food. My concern is when we stop her prednisone 20mg daily then every other day, both times her ears started getting the open sores inside the flaps. It seems to happen when she goes outside to play or spends too much time outside with me and her "papa". I call my vet before it gets out of control again and he puts her back on prednisone for a few days, clears up imediately. As soon as medicine stops, within 2 days her ear sores start with her licking all over. We do not want to keep her on prednisone unless absolutely necessary. Has anyone encountered these problems. She is 9 and has been healthy up until this illness started in December. I would appreciate any advise you all might have, holistic, medicinal, we are pretty desperate as not to have her medicated the rest of her life

Allergy/Skin Issue