What are the other Names for this Condition? (Also known as/Synonyms)

• De Quervain Thyroiditis
• Migratory Thyroiditis
• Painful Subacute Thyroiditis

What is Subacute Granulomatous Thyroiditis? (Definition/Background Information)

• Subacute Granulomatous Thyroiditis (SGT) is a painful disorder involving the thyroid gland that is typically self-limiting. Even though, the course of the condition is highly variable, the inflammation of the thyroid gland resulting in associated signs and symptoms, only last for a short duration (few months)
• Subacute Granulomatous Thyroiditis, also known as De Quervain Thyroiditis, is typically noted in young and middle-aged women. The cause of the condition is not well understood, but it is reportedly triggered by recent viral infections such as hepatitis, enterovirus, or mumps virus infection
• Subacute Granulomatous Thyroiditis constitutes variable phases, which includes hyperthyroidism (increased thyroid hormone secretion), hypothyroidism (decreased thyroid hormone secretion), and a return to euthyroid state (a state of normal thyroid function). Some individuals may not present all the three phases
• The signs and symptoms of Subacute Granulomatous Thyroiditis depend on the clinical state of the condition, but severe pain in the neck region with acute onset is characteristic of this condition. The condition may also present with fever, fatigue, swallowing difficulties, and weight loss
• A diagnosis of Subacute Granulomatous Thyroiditis is made by measuring thyroid hormone levels in blood and through an ultrasound scan of the thyroid gland. In many individuals, no treatment may be necessary, and the condition is known to resolve within a few weeks to months. The prognosis of Subacute Granulomatous Thyroiditis is mostly excellent

Who gets Subacute Granulomatous Thyroiditis? (Age and Sex Distribution)

• It is reported that Subacute Granulomatous Thyroiditis form between 3-6% of all types of thyroiditis
• Individuals of all ages may be affected, although most cases are noted in adults
• The condition more often affects females (especially women between 30-50 years) than males; the female-male ratio is between 2:1 to 6:1
• Individuals of all racial and ethnic groups may be affected
• Most cases are reported during summer and autumn months

What are the Risk Factors for Subacute Granulomatous Thyroiditis? (Predisposing Factors)

The risk factors associated with Subacute Granulomatous Thyroiditis include:

• Female gender, especially young and middle-aged women
• Viral infections that may include:
  • Adenovirus infections
  • Cytomegalovirus infection
  • Echovirus infection
  • Enterovirus infection
  • Epstein-Barr virus infections
  • Group A and B coxsackie virus infections
  • Hepatitis B and C virus infections
  • Influenza
  • Mumps
• Positive family history of the condition (or other forms of thyroiditis)
• Presence of autoimmune disorders or a family history of the same

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Subacute Granulomatous Thyroiditis? (Etiology)

The exact cause of Subacute Granulomatous Thyroiditis is not well-established. It is believed to have a viral origin, being triggered by a recent viral illness (mostly an upper respiratory tract infection).

What are the Signs and Symptoms of Subacute Granulomatous Thyroiditis?

The signs and symptoms of Subacute Granulomatous Thyroiditis (SGT) may include:

• SGT typically begins with a severe pain in the thyroid gland (neck region) that radiates to the ears, jaw, and down the chest
• The pain may increase during swallowing of food, or while moving/rotating one’s head
• In some individuals, the pain may be migratory, meaning different parts of the gland may present pain at different times
• The thyroid gland is present as a tender mass that presents diffuse pain
• Systemic symptoms may include low-grade fever, tiredness, and malaise

The course of the condition varies from one individual to another but may include hyperthyroidism and hypothyroidism.

The associated signs and symptoms of hyperthyroidism may include:

• Sleeping difficulties including insomnia
• Excess sweating and intolerance to heat
• Increased to excessive hunger
• Irritation, restlessness, and nervousness
• Protrusion of the eyes
• Menstrual abnormalities in women; menstruation may be irregular or short
• Abnormal heartbeat rate including rapid heart rate
• Weight loss

The signs and symptoms associated with hypothyroidism may include:

• Difficulty concentrating or thinking
• Fatigue and tiredness
• Dry skin
• Hair loss, which may be in excess while showering
• Constipation or difficult bowel movements
• Weight gain that may be slow and gradual
• Heavy and irregular periods (in women)
• Abnormal sensitivity to cold; the affected individuals may not tolerate cold very well

How is Subacute Granulomatous Thyroiditis Diagnosed?

The diagnosis of Subacute Granulomatous Thyroiditis may involve the following tests and procedures:

• Complete evaluation of medical history and a thorough physical examination
• Assessment of the signs and symptoms
• Blood tests to evaluate the levels of:
  • T3 and T4; thyroid hormones produced in the thyroid gland
  • Serum TSH 
  • Antithyroid peroxidase antibody (anti-TPO); antibodies against thyroid peroxidase, an enzyme in the thyroid gland
  • Antithyroglobulin antibody; antibodies interacting with thyroglobulin, a protein found on the thyroid cells
  • Tests to diagnose any viral infections
• Ultrasound scans of the thyroid gland
• Fine needle aspiration (FNA) biopsy or core biopsy of the thyroid gland, if needed
• Tests and procedures to rule out any underlying condition, if necessary

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Subacute Granulomatous Thyroiditis?

Subacute Granulomatous Thyroiditis is a generally self-limiting condition that usually does not present any complications, apart from severe pain.

In some cases, the potential complications associated with the condition include:

• Emotional stress due to concerns of a malignancy (such as throat cancer)
• Thyrotoxicosis, or the presence of excess thyroid hormones in the body tissues
• Mental health issues such as depression
• Increased risk of infection

How is Subacute Granulomatous Thyroiditis Treated?

In many cases, Subacute Granulomatous Thyroiditis is a self-limiting condition that resolves on its own. If treatment is provided, then it is based upon the presenting symptoms:

• Pain relievers that may include non-steroidal anti-inflammatory drugs (NSAIDs)
• During the hyperthyroid stage, anti-thyroid drugs are usually not necessary
• Sometimes, thyroid hormone replacement is needed if symptoms of hypothyroidism persist and/or are severe
• Beta-blockers are known to relieve an elevated heart rate and excessive sweating, which may be prescribed if necessary
• Follow-up care with screening and check-ups are important at regular intervals

How can Subacute Granulomatous Thyroiditis be Prevented?

The exact cause of Subacute Granulomatous Thyroiditis is not known, and hence currently, there is no known preventive method reported for the condition. However, considering certain factors may help lower one’s risk for the same: 

• Knowledge about one’s family history is helpful in assessing future risks for the condition
• Early detection and prompt treatment of autoimmune disorders may lower one’s risk
• Availing prompt treatment for any viral infections

What is the Prognosis of Subacute Granulomatous Thyroiditis? (Outcomes/Resolutions)

• In a vast majority of cases, Subacute Granulomatous Thyroiditis resolves on its own over a few months. Once the condition resolves, the thyroid gland function comes back to normalcy (euthyroid state)
• A close follow-up is necessary at periodic intervals; during the follow-up visits, thyroid hormone levels in blood need to be checked.

Additional and Relevant Useful Information for Subacute Granulomatous Thyroiditis:

The following article links will help you understand thyroid-stimulating hormone (TSH), total T3, and total T4 laboratory tests:

http://www.dovemed.com/common-procedures/procedures-laboratory/thyroid-stimulating-hormone-tsh-test/

http://www.dovemed.com/common-procedures/procedures-laboratory/total-t3-blood-test/

http://www.dovemed.com/common-procedures/procedures-laboratory/total-t4-blood-test/