- Seventeen patients, constituting 12.1% of 140 consecutively seen cases of chronic urticaria, demonstrated thyroid autoimmunity with thyroid microsomal antibodies (TMAs) in serum titers greater than or equal to 1:1,600. Eight of these 17 patients had goiter or thyroid dysfunction. In a control group of 477 consecutively seen patients, only 27 (5.6%) had similar TMA titers. Routine and special immunologic test results in this group of 17 patients did not differ from those found in other patients with chronic urticaria and angioedema (CUA), and the only notable clinical feature was that all 17 had angioedema. The age and sex distribution and thyroid features of these 17 patients were similar to those described in autoimmune thyroiditis. Patients (especially women) with CUA should be tested for the presence of TMAs. In this subgroup, CUA may have an autoimmune basis.