Subacute granulomatous thyroiditis, or painful thyroiditis, is a form of thyroid disease that occurs equally in both men and women. It usually starts out as a harmless viral illness such as the flu or a cold which invades the thyroid gland causing thyroiditis. This type of inflammation is quite painful and you may find that the front of your throat is sore to the touch. Often this pain extends to the jaw or ear and can be confused with a whole host of other diseases including temporomandibular joint problems (commonly referred to as TMJ), ear infections or even Strep throat. Sometimes only one lobe of the thyroid is affected causing pain and swelling on just one side of the neck instead of both.
Gradually the thyroid recovers and stops spilling thyroid hormone into the blood stream. The thyroid gland begins to shrink and becomes less tender. The thyroid cells recover and are usually able to produce normal amounts of thyroid hormone. Occasionally, however, the thyroid has been destroyed and can never produce normal quantities of thyroid hormone. In this case, permanent hypothyroidism results and thyroid hormone replacement medication is necessary.
The diagnosis of painful thyroiditis is made by routine thyroid function blood tests which may initially show an overactive thyroid because of the sudden release of a surplus of thyroid hormone into the blood stream as the thyroid is attacked by the virus. A radioactive iodine scan will show almost no concentration of the radioiodine by the thyroid cells because these cells are temporarily injured during the inflammatory process. In the situation where only one side of the thyroid gland is enlarged, it can mimic the symptoms of thyroid cancer, therefore a thorough history, including recent viral infections, must be considered. In addition, if the thyroid only shrinks on one side after the infection, it also may be misdiagnosed as a thyroid cancer, therefore it is important that you inform your doctor about the painful initial swelling.
Sometimes medications like aspirin or ibuprofen can be taken under the direction of a physician to help decrease the amount of pain. If the thyroid cells recover, no additional medication is needed. However, if the damage is permanent, replacement doses of thyroid hormone medication must be taken for the rest of your life to treat the hypothyroidism. There is no way to tell who will eventually end up with an underactive thyroid gland. Therefore it is very important to have routine visits with your doctor, to make sure that your thyroid gland is still functioning normally. This information is obtained by routine thyroid function blood tests.