Thyroid Autoimmunity in Patients with Chronic Urticaria.

INTRODUCTION: chronic urticaria (CU) is a skin disorder characterized by transient, pruritic wheals persisting for longer than 6 weeks. The etiopathogenesis of the disease is still unclear, but there is evidence that autoimmunity and endocrine dysfunction may be involved.

AIM: the aim of this study was to determine whether chronic urticaria is statistically associated with thyroid autoimmunity.

PATIENTS AND METHODS: in a prospective case-control study, we compared the frequency of thyroid auto-antibodies (thyroglobulin antibody, anti-Tg and thyroid peroxidase antibody, anti-TPO) in 70 patients with chronic urticaria and in 70 healthy volunteers. Thyroid auto-antibodies and thyroid hormones (thyroxine (T4), triiodthyronine (T3) and thyroid stimulating hormone (TSH) were measured in all subjects.

RESULTS: thyroid functional abnormalities were found in 8 (11.43%) patients. Anti-Tg and anti-TPO were positive in 16 (23%) and 21 (30%) patients, respectively. In control group, only one subject (1.42%) had abnormalities in thyroid hormonal status, and two subjects (2.86%) had positive thyroid auto-antibodies. Compared with the control group, the frequency of both anti-Tg and anti-TPO was significantly higher in those with chronic urticaria (P < 0.05).

CONCLUSION: this study shows a significant association between chronic urticaria and thyroid autoimmunity, and that tests to detect thyroid auto-antibodies are relevant in patients with chronic urticaria.