Endocrine Abstracts

Background: Chronic urticaria (CU) is defined as recurrent episodes of hives with or without angioedema of at least 6 weeks’ duration; in almost 40% of the cases an underlying autoimmune process is implicated. Increased prevalence of autoimmune thyroid disease (ATD) has been reported in patients with CU, however the clinical significance of this finding remains controversial. Moreover, data concerning the prevalence of CU in patients with ATD are few.

Objective: To evaluate the presence of CU in patients with newly diagnosed thyroid disease in order to assess possible association of ATD with CU.

Patients and methods: Thirty seven patients (28 women (14 pre- & 14 postmenopausal), 9 men) aged 19–78 years (50.7±17.6) underwent a clinical examination, a biochemical evaluation (routine biochemistry, thyroid function tests, anti-TPO and anti-Tg levels, total IgE levels, CRP), skin prick tests (SPTs) in 13 common inhalant allergens and a thyroid ultrasound. No patient was receiving any medication affecting thyroid function at the time of the study. CU diagnosis was based on documented history of typical lesions while the presence of atopy was assessed by medical history of atopic diseases (allergic rhinitis, asthma) and/or positive SPTs.

Results: ATD was diagnosed in 25/37 (67.6%) patients: Hashimoto thyroiditis in 24 (18 euthyroid, 6 with subclinical hypothyroidism) and history of Graves’ disease in 1 euthyroid patient with nodular goiter. The remaining 12/37 patients (32.4%) had non-autoimmune thyroid disease (non-ATD). CU was diagnosed in 8/25 (32.0%) of patients with ATD and in 2/12 (16.7%) patients with non-ATD and atopy was assessed in 12/25 (48.0%) and in 3/12 (25.0%) respectively. Although a tendency for higher prevalence of CU and atopy was observed in ATD compared to non-ATD patients, this difference did not reach statistical significance.

Conclusion: These findings suggest that CU affects a large proportion of patients with ATD. It is uncertain whether these diseases share common autoimmune mechanisms, especially in atopic individuals, or their concurrence is accidental. Further investigation is needed in large series of patients with ATD and CU, especially in those with the autoimmune form of CU.