Subacute thyroiditis involves swelling (inflammation) of the thyroid gland that usually follows an upper respiratory infection.
Subacute thyroiditis is a rare condition. It is thought to be caused by a viral infection. The condition often occurs after a viral infection of the upper respiratory tract, such as mumps and influenza.
Subacute thyroiditis occurs most often in middle-aged women with recent symptoms of a viral respiratory tract infection.
The most obvious symptom of subacute thyroiditis is pain in the neck. Sometimes the pain can spread (radiate) to the jaw or ears. Painful enlargement of the thyroid gland may last for weeks or months.
Other symptoms include:
Symptoms of too much thyroid hormone (hyperthyroidism) may include:
Later, symptoms of too little thyroid hormone (hypothyroidism) may occur, including:
Usually thyroid gland function returns to normal. But in some cases hypothyroidism may be permanent.
Laboratory tests early in the course of the disease may show:
Laboratory tests later in the disease may show:
There may be low levels of antithyroid antibodies. Thyroid gland biopsy is usually not needed, but will show a type of inflammation characteristic of this condition. Lab tests should return to normal as the condition goes away.
The purpose of treatment is to reduce pain and inflammation and treat hyperthyroidism, if it occurs. Anti-inflammatory medications such as aspirin or ibuprofen are used to control pain in mild cases.
More serious cases may need temporary treatment with steroids (for example, prednisone) to control inflammation. Symptoms of hyperthyroidism are treated with a class of medications called beta blockers (for example, propranolol, atenolol). Antithyroid drugs or thionamides are not effective in treating this condition.
The condition should improve on its own. However, the illness may last for months. Long-term or severe complications do not usually occur.
Call your health care provider if:
MMR (measles, mumps, rubella) immunization (vaccine) or flu vaccine may help prevent these conditions, which can cause subacute thyroiditis. Other causes may not be preventable.
De Quervain's thyroiditis; Subacute nonsuppurative thyroiditis; Giant cell thyroiditis; Subacute granulomatous thyroiditis