Suggest Treatment For Swollen And Painful Lips

I am a professional flute player who has been suffering from extreme lip swelling ( with blisters, chapping, and a ton of pain ) for six months with seemingly no answer as to why it has started. I have seen a neurologist, dentists, primary care doctors, had blood tests done, allergy tests ( food and metal patch testing) been put on a heavy zyrtec regiment, anti inflammatories, antihistamines..etc - EVERYTHING. It only seems to respond to steroid prednisone dose packs - which I cannot live on forever. After finishing the dose pack within two weeks my lips are huge and painful again. I cannot play my instrument or continue my career this way. I ve been encouraged to see a rhuemetologist next. Please advise..