Last update:
07-Jul-2004

Both genetic and exogenous factors predispose to the development of chronic autoimmune thyroiditis. It is a common disorder as, based on antithyroid antibody estimation, it affects 10–15% of women at the age of 20 and 30–33% of women over the age of 50 years. It affects women more than men in a ratio of 3–5/1 and is the most common cause of goiter and hypothyroidism. High levels of antithyroid antibodies can be detected in the blood in approximately 90% of patients and are the hallmark of the disorder. Among patients with detectable antithyroid antibodies 50–75% are euthyroid, 25–50% have subclinical hypothyroidism and 5–10% have overt hypothyroidism. On palpation the thyroid is firm and its surface is often irregular and may be nodular. Ultrasonography does not always contribute to the diagnosis, but assists in the identification of thyroid nodules and in estimation of the size of the gland. Scintigraphy assists in the diagnosis only in the case of silent thyroiditis where low radionuclide uptake is observed. Fine needle aspiration biopsy should not be performed routinely, except in the case of nodules which raise the suspicion of cancer. Silent and postpartum thyroiditis are considered to be manifestations of chronic autoimmune thyroiditis. The detection of antithyroid antibodies is not an indication for thyroxine therapy, except in the case of hypothyroidism. As chronic autoimmune thyroiditis is common and hypothyroidism has a negative impact, thyroid hormones should be measured in women over 50 years, in pregnancy and postpartum, and in women and men who have hypercholesterolemia.

Key words: Antithyroid antibodies, Hashimoto’s disease, Hypothyroidism, Postpartum thyroiditis, Silent thyroiditis.