Prognostic significance of thyroid autoantibodies in Urticaria

Abstract

Background: The association between chronic urticaria and thyroid autoantibodies is now generally accepted, and some authors recommend screening for thyroid autoimmunity and function in all patients with chronic urticaria for early identification of patients who might require treatment of underlying thyroid dysfunction or follow-up. However, the prognostic significance of thyroid autoantibodies in urticaria patients is still unclear. Objective: To evaluate antibody reactivity as a prognostic factor, the association between antibody positivity and disease duration were analyzed. Methods: Medical records from March 2002 to October 2010 of urticaria patients (M: 41, F: 125), who were tested for thyroid auto-antibodies at their first visit, were collected and reviewed for the duration of urticaria. Patients with a 6-week or longer history of urticaria were categorized into the chronic urticaria group; patients whose urticaria resolved within 6 weeks were categorized into the acute urticaria group. Results: A positive result to the thyroid autoantibody was shown by 28.9% of chronic urticaria patients and 10.7% of acute urticaria patients. Average duration of urticaria in patients who were thyroid autoantibody positive was 33.9 weeks, while patients with thyroid autoantibody negative tests had urticaria for 6.9 weeks on average. The frequency of a positive result to only the thyroid peroxidase antibody was different between the chronic urticaria group (15.6%) and the acute urticaria group (2.5%). Conclusion: According to our results, the average duration of urticaria in patients with thyroid autoantibodies was significantly longer than in urticaria patients without thyroid autoantibodies. Thyroid autoantibodies were statistically meaningful prognostic factors predicting the duration of urticaria.