I have a little more insight for you...get the tests, see an endo, and get an ultrasound of your thyroid. Ive had urticaria for 3 years. Allergist didnt even check for autoimmune disease. After years of symptoms and blood work normal, they have found 2 nodules and goiter on thyroid. Definate link.
Yes - urticaria can be linked and keeping TSH in the low normal range may help (0.3-1.0) -- else, no suggestions from a thyroid standpoint.