I am on thyroxine and have been for a number of years, Every few months I get very itchy swollen welts on my body , also have facial swelling. this swelling and the welts only appear on one side of my body, after a few days when the symptoms go, the same symptoms happen on the other side of my body, I mean 1/2 my lip will swell, 1/2 my tongue , the itchy welts will appear. I have Hashimotos and understand that this is an autoimmune disease.