IgE antithyroid antibodies in patients with Hashimoto's disease and chronic urticaria.

Although chronic urticaria may be associated with the presence of serum anti-thyroid antibodies, it is not known whether these antibodies play a causal role in the urticaria. We therefore sought to determine whether the anti-thyroid antibodies seen in patients with urticaria were of the IgE class. Using commercial ELISA kits for measuring serum IgG anti-thyroglobulin and anti-thyroid peroxidase antibodies, we modified the procedure to detect IgE antibodies. We examined sera from 20 patients with urticaria who had IgG anti-thyroid antibodies and from 12 patients with IgG antithyroid antibodies who did not have urticaria. Only 2 of 20 patients with urticaria and IgG anti-thyroid antibodies had detectable IgE anti-thyroid antibodies: 1 patient had anti-thyroid peroxidase IgE antibody and 1 patient had anti-thyroglobulin IgE. IgE anti-thyroid antibodies do not appear to play a causal role in urticaria in the majority of patients.