Serum antithyroid antibodies in female patients with chronic urticaria.

OBJECTIVE To determine the frequencies of serum antithyroglobulin and antimicrosomal autoantibodies in female patients with chronic urticaria, and the association between thyroid autoantibodies and chronic urticaria, if any. STUDY DESIGN Non-interventional, case-control analytic study. PLACE AND DURATION OF STUDY This study was carried out by the Department of Physiology, Dow University of Health Sciences, Karachi, from December 2004 to January 2006 on patients selected from Department of Dermatology and Medical Units of Civil Hospital, Jinnah Postgraduate Medical Centre and The Aga Khan University Hospital, Karachi and from the Community Clinics in Karachi. METHODOLOGY A total number of 90 subjects were enrolled and divided in three groups consisting of 30 patients each. Group 1 comprised of patients with diagnosis of chronic urticaria, Group 2 of diagnosed cases of hypothyroidism with/without urticaria, and Group 3 of normal age and gender-matched healthy volunteers. In all patients, serum antithyroid autoantibodies (antithyroglobulin and antimicrosomal) and thyroid profile (serum T3, T4 and TSH levels) was carried out. Chi-square test was used to determine significance of proportion of variables at p < 0.05. RESULTS Elevated titres of antithyroglobulin antibodies were found to be present in 9 (30%) patients in Group 1 (chronic urticaria), 24 (80%) patients in Group 2 (known cases of hypothyroidism) compared to control. Elevated titres of antimicrosomal antibodies were found to be present in 13 (43.3%) patients in Group 1, 27 (90%) patients in Group 2 (known cases of hypothyroidism) compared to control. The association between hypothyroidism and chronic urticaria with regard to autoantibodies titres was highly significance (p <0.001). CONCLUSION A highly statistically significant association was found between chronic urticaria and hypothyroidism with special regard to antithyroglobulin and antimicrosomal autoantibodies. Therefore, assays of these two autoantibodies are justified for the early diagnosis of autoimmune thyroiditis in combination with chronic urticaria for better treatment options.