There is no such report on the association of thyroid autoantibodies and chronic urticaria in Taiwan population yet. This study is designed to investigate the prevalence of thyroid autoimmunity associated with chronic urticaria in Taiwanese population. In addition, we intend to find out the change in the level of thyroid autoimmunity after the treatment in order to further understand their relationship. We also intend to find out the prognostic parameters in patients with the presence of thyroid autoimmunity and chronic urticaria.