Hello Lunar Lady,
I assume you have been through all the tests and thus the diagonosis of Chronic Urticaria.
Chronic Urticaria recent findings suggest that in 25-45% of patients, CIU is not idiopathic but is an autoimmune disease.
Doxepin (Sinequan, Zonalon) -- Inhibits histamine and acetylcholine activity.
10-50 mg PO at bedtime is the recommended range.
This is a tough illness to suffer through, but I would certainly talk with your physician re your meds and the possibility of an underlying disease process that is causing your urticaria.
Prednisone works but it is not for long term use. Please remember I am not a professional, just giving you some info.
Keep working with your physician and posting here.
A warm welcome to Healing Well.