What is thyroiditis?

Thyroiditis is a disorder that is caused by inflammation of the thyroid gland. Inflammation is a complex process that is controlled by the immune system. It involves different types of white blood cells that move out of the bloodstream to infiltrate tissues throughout the body. These white blood cells release chemical compounds called mediators that trigger responses in surrounding tissues. The responses triggered by these mediators contribute to the pain, swelling, redness, and warmth associated with most inflammatory processes. Inflammation of the thyroid gland may cause destruction of thyroid tissue. This may lead to the uncontrolled release of excess amounts of thyroid hormone, which may in turn lead to the development of thyrotoxicosis.

There are two forms of thyroiditis that commonly lead to the development of thyrotoxicosis. Subacute thyroiditis is a disorder that usually presents with symptoms of pain and tenderness in the lower front portion of the neck. It often develops in patients who may have had a recent viral infection. It is also known as granulomatous thyroiditis or De Quervian's thyroiditis. Silent thyroiditis is a disorder that presents with evidence of autoimmune destruction of the tissue that makes up the thyroid gland. It frequently develops in women of childbearing age. It is also known as lymphocytic thyroiditis or painless thyroiditis. Silent thyroiditis that develops in a woman who has recently given birth is usually called postpartum thyroiditis.

How is thyroiditis diagnosed?

A diagnosis of subacute thyroiditis may be suspected when a patient presents with pain and tenderness in the lower front portion of the neck. Thyroid function tests may reveal evidence of thyrotoxicosis in more than half of all patient diagnosed with subacute thyroiditis. An additional blood test called an erythrocyte sedimentation rate that reflects underlying inflammation may be abnormally elevated. Patients who are diagnosed with silent thyroiditis usually do not present with any characteristic symptoms apart from those that may be associated with thyrotoxicosis or subsequent hypothyroidism. Mild enlargement of the thyroid gland may be evident on physical examination. Blood tests usually reveal increased levels of autoantibodies directed against structures in the thyroid gland. A suspected diagnosis of subacute thyroiditis or silent thyroiditis may be confirmed when thyroid uptake study results demonstrate little or no uptake of tracer in the region of the thyroid gland.

How is thyroiditis treated?

The treatment of thyrotoxicosis that develops in the setting of subacute thyroiditis or silent thyroiditis usually focuses on the use of drugs called beta blockers. When administered in effective doses, beta blockers help to control the palpitations, anxiety, and tremulousness associated with severe thyrotoxicosis. In cases of subacute thyroiditis that present with severe pain and tenderness, anti-inflammatory agents may be used to help reduce discomfort as inflammation gradually resolves. Common anti-inflammatory agents used to treat subacute thyroiditis include nonsteroidal anti-inflammatory drugs, cyclooxygenase-2 inhibitors, and glucocorticoids. Patients diagnosed with subacute thyroiditis or silent thyroiditis may need to have thyroid function tests checked on a regular basis to see if they transition to a different state. Continued destruction of tissue may inhibit the thyroid gland’s ability to produce and secrete thyroid hormone. This may lead to the development of hypothyroidism characterized by underactivity of the thyroid gland .