Thyroiditis is an endocrine disorder defined by an inflammatory alteration of the thyroid gland. Linked to both inflammatory and infectious causes, thyroiditis leads to the disruption of thyroid hormone secretion and involves very diverse clinical and biological developments.
What is thyroiditis?
Definition of thyroiditis
Thyroiditis is an endocrine disorder defined by an inflammatory alteration of the thyroid. The thyroid is a butterfly-shaped gland located at the base of the neck secreting two main hormones, tri-iodothyronine (T3) and tetra-iodothyronine or thyroxine (T4), regulated by TSH or pituitary thyroid regulating hormone.
The hormones T3 and T4 affect many functions of the human body such as basal metabolism, energy production, heat production, the nervous system, and the skeleton. They act on the muscles, heart, digestive tract, hair, etc.
Linked to both inflammatory and infectious causes, thyroiditis leads to the disruption of thyroid hormone secretion and involves very diverse clinical and biological developments.
Types of thyroiditis
Thyroiditis can be acute, subacute, or chronic and represent a wide range of thyroid pathologies:
- Hashimoto’s thyroiditis is a chronic autoimmune disease characterized by abnormally high levels of antithyroid antibodies in the blood and white blood cells that attack the thyroid and cause damage. This “autoimmune destruction” leads to hypothyroidism, i.e. the thyroid does not secrete enough thyroid hormones;
- Subacute Quervain’s thyroiditis, also called subacute granulomatous thyroiditis, is associated with hyperthyroidism – increased synthesis of thyroid hormones;
- Bacterial thyroiditis, rare, but associated with mortality of up to 12%, is most often euthyroid;
- Painless thyroiditis with initial hypertrophy is considered a subacute presentation of Hashimoto’s thyroiditis;
- Postpartum thyroiditis begins with a hyperthyroid phase followed by a hypothyroid phase;
- Drug-induced thyroiditis;
- Radiation thyroiditis;
- Fibrous thyroiditis, or Riedel’s thyroiditis, occurs in only 0.05% of patients who have undergone thyroid surgery;
- Palpation thyroiditis or post-traumatic thyroiditis.
Causes of thyroiditis
Hashimoto’s thyroiditis, a chronic autoimmune disease, frequently manifests itself with other autoimmune diseases: vitiligo, type 1 diabetes, Addison’s disease, primary hypoparathyroidism, primary hypogonadism, primary and secondary Sjögren’s syndrome;
Subacute Quervain’s thyroiditis is due to a viral infection or a post-viral inflammatory process: Coxsackie virus (or foot-hand-mouth infection), mumps, measles, adenovirus…;
Bacterial thyroiditis is mainly caused by staphylococci or streptococci;
Postpartum thyroiditis develops in the first months after delivery and is usually transient;
Drug-induced thyroiditis is triggered in particular by taking drugs containing iodine, lithium, and certain products used in oncology (interleukin, interferon);
Radiation thyroiditis follows treatment with radioactive iodine;
Fibrous thyroiditis or Riedel’s thyroiditis, rare, occurs in only 0.05% of patients who have undergone thyroid surgery. It is manifested by a systemic fibrotic process and affects neighboring tissues;
Palpation thyroiditis, or post-traumatic thyroiditis, occurs after intensive palpation or surgery.
Diagnosis of thyroiditis
The diagnosis of thyroiditis and its type is made mainly from the thyroid function and symptoms of the patient:
- Medical history;
- Clinical signs: enlarged thyroiditis, hard, painful, painful and unilateral swelling of the neck, solid and nodular goiter…;
- Biological exploration by determination of TSH (pituitary thyroid regulating hormone) and thyroid hormones T3 and T4 to confirm and evaluate the extent of dysfunction: hyperthyroidism, euthyroidism, hypothyroidism;
- An ultrasound, sometimes scintigraphy, to differentiate between two types of thyroiditis;
- A puncture (identification of a possible trigger germ);
- Sometimes a biopsy.
The determination of antithyroid antibodies (ATAs) – abnormal antibodies (autoantibodies) that attack the thyroid gland – incorporates the diagnosis in the last place so as not to confuse the doctor. It is especially useful in cases of hyperthyroidism to differentiate thyroid autonomy and Graves’ disease (autoimmune hyperthyroidism).
People affected by thyroiditis
While thyroiditis can affect the general population, it is more common in women in general.
In areas with adequate iodine intake, Hashimoto’s thyroiditis is the most common cause of acquired hypothyroidism in children and adolescents.
Factors promoting thyroiditis
Different factors can promote the development of thyroiditis:
- A genetic terrain;
- Gender: women are more prone to thyroiditis;
- The aftermath of childbirth;
- Iodine overload;
- Viral infections;
- Irradiation in the neck;
- Stress.
Symptoms of thyroiditis
Thyroid pain
Thyroid pain, which can radiate to the jaw or ears, is the main symptom of subacute Quervain’s thyroiditis. Flu-like symptoms can be added to it associating muscle pain, malaise, fever, and fatigue.
Sore throat
Symptoms of bacterial thyroiditis include unilateral sore throat of rapid onset associated with fever, chills, and sometimes redness.
Nodular goiter
Hashimoto’s thyroiditis is painless, usually has a solid goiter, resulting from the enlargement of the thyroid, and nodular – a nodule is a small, circumscribed mass present on the gland.
Other symptoms
- Exercise fatigue and cerebral fatigue;
- Weight gain;
- Puffy face;
- Curly fingers;
- Constipation;
- Joint pain;
- Mood swings;
- Stress intolerance with tachycardia;
- Psychomotor slowdowns;
- Hoarseness and symptoms of compression of the trachea and/or esophagus (fibrous thyroiditis);
- Note that the prevalence of asymptomatic thyroiditis is very high.
Treatments for thyroiditis
Each thyroiditis has specific etiologies, an adapted treatment will be proposed according to the diagnosis made.
Among the classic treatments, however, we can mention:
- The prescription of nonsteroidal anti-inflammatory drugs (NSAIDs) for the treatment of subacute Quervain’s thyroiditis;
- Antibiotics for bacterial thyroiditis;
- L-thyroxine substitution therapy is indicated for Hashimoto’s thyroiditis in cases of overt hypothyroidism or desire for pregnancy;
- Surgery may be considered for fibrous thyroiditis.
Preventing thyroiditis
Some tips can prevent the onset or recurrence of thyroiditis:
- Monitor TSH (pituitary thyroid regulating hormone) before, during, and after treatment;
- Ensure adequate iodine intake;
- Do not smoke, especially during pregnancy;
- Manage stress with relaxation techniques.
Image Credit: Image by stefamerpik on Freepik
