What are the physical triggers for chronic urticaria?
A number of different etiologic factors have been reported as proposed causes of chronic urticaria. Autoimmunity is thought to be one of the most frequent causes of chronic urticaria. Various autoimmune or endocrine diseases have been associated with urticaria, including systemic lupus erythematosus, cryoglobulinemia, juvenile rheumatoid arthritis, and autoimmune thyroid disease.
@kanish There is a significant association of chronic urticaria with thyroid autoimmunity, and antithyroid autoantibodies are significantly increased in patients with chronic urticaria. The prevalence of thyroid autoimmunity among chronic urticaria patients varies from 4.3% to 57% in the literature, and about 5-10% of chronic urticaria patients have abnormal thyroid function. In one study comparing 70 patients with chronic urticaria with 70 healthy controls, it was found that 23-30% of patients with chronic urticaria had either or both antithyroglobulin antibody (anti-Tg) and antimicrosomal antibody (antithyroid peroxidase [TPO]), and as many as 5-10% had abnormal thyroid function.