thyroiditis



Overview

Acute, subacute, and chronic inflammation of the thyroid tissue manifested by abnormalities in the size, texture, and function of the thyroid gland, which may be accompanied by tenderness and a localized inflammatory response caused by autoimmune abnormalities, infections, medications, and radiation, etc. Treatment of thyroid tissue damage is primarily pharmacological, and surgical intervention may be indicated in case of failure.

Definition

Thyroiditis is a heterogeneous group of diseases characterized by damage to thyroid tissue due to autoimmune abnormalities, infections, drugs, and radiation.

Thyroiditis can present as acute (purulent), subacute, or chronic inflammation.

The thyroid gland is an important endocrine organ of the human body, regulated by the pituitary gland, secreting thyroxine to promote the body’s material and energy metabolism, promote the physical and intellectual development of children, increase the excitability of sympathetic nerves, and participate in the stress response.

Inflammation of the thyroid gland can affect the secretion of thyroid hormones, leading to an increase or decrease in their secretion, which can lead to a series of pathophysiological changes, such as hyperthyroidism (hyperthyroidism) and hypothyroidism (hypothyroidism).

Classification

There are many ways to categorize thyroiditis and there are many different types.

They are categorized according to the urgency of onset

Acute thyroiditis

Rare, often a complication of acute pharyngitis and epiglottitis.

Most are caused by bacterial infections.

Subacute thyroiditis

Subacute thyroiditis is also known as granulomatous thyroiditis, viral thyroiditis, and giant cell thyroiditis.

It is a more common form of thyroiditis and is associated with viral infections.

It often occurs after upper respiratory tract infections or mumps.

Chronic thyroiditis

Chronic lymphocytic thyroiditis: also known as Hashimoto’s thyroiditis and autoimmune thyroiditis, is an autoimmune disease.

Fibrous thyroiditis: also known as chronic wood-like thyroiditis, this disease has significant fibrosis and vitreous changes, hard texture.

Classification according to etiology

Autoimmune thyroiditis

Also known as chronic lymphocytic thyroiditis.

It is characterized by the presence of serum autoantibodies against the thyroid gland and is characterized by inflammatory destruction of the thyroid gland.

These include Hashimoto’s thyroiditis, atrophic thyroiditis, thyroiditis with normal thyroid function, painless thyroiditis, and postpartum thyroiditis.

Non-autoimmune thyroiditis

It can be categorized as bacterial, viral, parasitic, radiological, traumatic, etc. thyroiditis.

Classified according to pathological features

Classified as purulent, granulomatous, lymphocytic thyroiditis, etc.

Classification according to symptoms

Painful thyroiditis: clinically characterized by thyroid pain.

Painless thyroiditis: clinically characterized by transient painless enlargement of the thyroid gland with abnormal thyroid function, it is a self-limited disease.

Pathogenesis

Thyroiditis encompasses a wide range of diseases, some of which are described below.

Acute thyroiditis

Occurs more often in children than in adults.

Subacute thyroiditis

Accounts for about 5% of thyroid disorders.

It is most common in women between the ages of 40 and 50.

The male-to-female ratio is 1:3-6.

It can occur throughout the year, but is more common in spring and fall.

Autoimmune thyroiditis

Autoimmune thyroiditis is the most common autoimmune thyroid disease.

Scholars in China have reported a prevalence of 1.6%, with an incidence rate of 6.9/1000.

The prevalence rate of autoimmune thyroiditis is reported to be 1-2% in foreign countries.

The most common age is 30 to 50 years old.

The male to female ratio is 1:(3-4).

Painless thyroiditis

It can occur at any age and is more common in women than in men.

Postpartum thyroiditis

It develops within 1 year after childbirth.

The prevalence in iodine-sufficient areas is 7%, and scholars in China have reported a prevalence of 7.2%.

Causes

Causes

Infection

Pathogenic microorganisms invade the thyroid tissue causing an inflammatory reaction.

Acute thyroiditis: associated with bacterial infection, such as staphylococcus and streptococcus.

Subacute thyroiditis: associated with viral infections, such as influenza virus, coxsackie virus, adenovirus and mumps virus, etc. These viruses can be found in the patient’s thyroid tissue or antibodies to these viruses can be found in the patient’s serum.

Autoimmunity

Abnormalities in the patient’s immune system produce a variety of antibodies that invade the thyroid gland and cause inflammation and destruction, and in severe cases, hypothyroidism can occur.

Other

It may also be associated with destruction of the follicular structure of the thyroid gland due to a variety of etiologic factors, including radiation damage, iodine overdose, medications, pregnancy, and trauma.

Symptoms

Symptoms vary between different types of thyroiditis.

Subacute thyroiditis

Subacute thyroiditis is characterized by an acute onset of symptoms, often preceded by an upper respiratory tract infection 1 to 3 weeks before the onset of the disease.

Localized symptoms

Localized symptoms of the thyroid gland are obvious, and may include mild to moderate enlargement of the thyroid gland, hard texture, and significant pain when touched.

Thyroid pain may radiate to the root of the ear, the jaw or the neck, and the pain is aggravated when swallowing.

Systemic Symptoms

General malaise, muscle pain, fever and generalized weakness.

Transient hypothyroidism may also occur, manifested by loss of appetite, abdominal distension, fear of cold, weight gain, and slowness of movement.

Early stage may be accompanied by hyperthyroidism manifestations, such as fear of heat and sweating, easy to hunger and eat more, weight loss, panic and impatience.

Hashimoto’s thyroiditis

Hashimoto’s thyroiditis has an insidious onset, early symptoms are atypical or asymptomatic, there may be pharyngeal discomfort or mild dysphagia, and a small number of hyperthyroidism manifestations.

In later stages, the patient may be diagnosed with goiter or hypothyroidism.

Painless thyroiditis

Thyroiditis is not associated with thyroid pain, but the thyroid gland may be enlarged, and hyperthyroidism or hypothyroidism may be present.

Postpartum thyroiditis

It occurs within 1 year after delivery and may present first with hyperthyroidism and then with hypothyroidism.

Complications

Hypothyroidism

Thyroiditis destroys thyroid tissue and causes a deficiency of thyroid hormones, which may lead to permanent hypothyroidism.

It may present with easy fatigue, chills, weight gain, slow movement, unresponsiveness, loss of appetite, and abdominal distension.

Hashimoto’s encephalopathy

Hashimoto thyroiditis may cause Hashimoto encephalopathy.

Hemiplegia, quadriplegia, aphasia, apraxia, dyslexia, cerebellar ataxia, sensory disturbances, etc. Psychiatric symptoms such as hallucinations and irritability may also occur.

In severe cases, coma or even death may occur.

Graves’ ophthalmopathy (thyroid-related eye disease)

Thyroid-related eye disease may occur when thyroiditis involves various soft tissues of the eye.

It presents with protruding eyes, foreign body sensation in the eyes, eye movement disorders, and diplopia.

Consultation

Department of Medicine

Endocrinology

Prompt medical consultation is recommended when the following symptoms occur

Touching a lump in the front of the neck, feeling that the neck is thicker and more painful than before, or having hoarseness or difficulty in swallowing.

Unexplained weight loss, hand tremor, fear of heat and sweating, protruding eyes, etc.

Unexplained weakness, poor concentration, chills, decreased sweating, mental depression, etc.

Emergency Department

Immediate medical attention is recommended when symptoms such as high fever, vomiting, convulsions, unconsciousness, coma, etc. occur.

Preparation for medical treatment

Preparation for medical consultation: registration, preparation of documents, common problems

Tips for the doctor

For the convenience of the doctor’s examination, try not to wear high-collared clothes or necklace jewelry.

If there is any weight change, it is recommended to record the time and result of weight measurement for the doctor’s reference.

In case of vomiting, you can use your cell phone to take photos of the vomit for the doctor’s reference.

Preparation Checklist for Doctor’s Visit

Have you noticed a lump in the front of the neck or the neck is thicker than before?

Is there any pain in the front of the neck, hoarseness, difficulty in pronunciation, difficulty in swallowing?

Is there irritability, panic, hunger, fear of heat and sweating, protruding eyes?

Is there fatigue, chills, lack of concentration, decreased sweating?

Is there any fever, and is there any runny nose, cough, sputum before fever?

Has there been any change in weight in the last six months?

Does anyone in a blood relative have thyroid disease?

Are there any allergies to drugs, food or other substances?

Are there any diseases such as hypertension, diabetes, systemic lupus erythematosus, rheumatoid arthritis, etc.?

Has there been an upper respiratory tract infection in the last 1-3 weeks?

Laboratory tests: thyroid function, thyroid autoantibodies, blood test, liver function, kidney function, C-reactive protein, blood sedimentation.

Imaging tests: thyroid ultrasound, thyroid radionuclide scan, eye CT, eye magnetic resonance imaging, heart ultrasound, pituitary magnetic resonance imaging

Other tests: electrocardiogram

Thyroid hormone: levothyroxine sodium tablets

Imidazoles: methimazole, carbimazole

Thiouracil: propylthiouracil

Beta-blockers: propranolol, metoprolol

Iodine-containing drugs: amiodarone, compound iodine solution, iodine-containing contrast media

Glucocorticoids: hydrocortisone, prednisone acetate, methylprednisolone, dexamethasone

Non-steroidal anti-inflammatory drugs: aspirin, ibuprofen, indomethacin

Diagnosis

Diagnosis is based on

Diagnosis is made on the basis of history, symptoms, physical examination, laboratory tests, and imaging studies.

Medical history

Previous upper respiratory tract infections such as sore throat and nasal congestion.

Thyroid disease such as hyperthyroidism.

Have had neck thyroid surgery, etc.

Autoimmune disease.

Clinical manifestations

Symptoms

Localized symptoms: thyroid gland is obviously enlarged, with or without tenderness.

Systemic symptoms: weakness, lethargy, drowsiness, abdominal distension, constipation, etc.

Compression symptoms: when the thyroid gland is enlarged and compresses the surrounding organs and tissues, corresponding compression symptoms such as dyspnea and hoarseness will appear.

Physical examination

The thyroid gland in the neck is obviously enlarged and hard, with no tremor.

There is no murmur in the blood vessels of the neck on auscultation.

Laboratory examination

Erythrocyte Sedimentation Rate (ESR)

Erythrocyte sedimentation rate, also known as hematocrit, can help to understand the progression and changes in the disease.

Early in the course of the disease, the sedimentation rate increases, suggesting an inflammatory response.

Routine blood tests

White blood cell, neutrophil, and lymphocyte counts can be tested to determine the severity of the disease.

Fasting is not required before the test.

Thyroid Function Test

The main indicators include serum thyroid stimulating hormone (TSH), total thyroxine (TT4), free thyroxine (FT4), total triiodothyronine (TT3), free triiodothyronine (FT3).

Thyroid function can be assessed and thyroiditis can be staged.

Subacute thyroiditis is usually categorized into the following three stages.

Thyrotoxic phase: elevated serum T3 and T4, decreased TSH levels, and decreased 131I uptake.

Hypothyroidism stage: blood T3 and T4 levels gradually decrease to below normal, blood TSH values rise above normal, and 131I uptake rate gradually recovers.

Recovery phase: blood T3 and T4 levels decrease, TSH levels increase, and serum T3, T4, TSH and 131I uptake rate return to normal in the latter two phases.

Antibody Detection

Thyroid autoantibodies can be detected, mainly thyroid peroxidase antibody (TPOAb) and thyroglobulin antibody (TgAb).

Patients with chronic thyroiditis show high titer positivity for TPOAb and TgAb.

These antibodies are present in patients with painless thyroiditis and postpartum thyroiditis, and TPOAb is more important for diagnosis.

Antibody testing is often negative in patients with acute thyroiditis.

Imaging

Color Doppler ultrasound: to check for changes in the volume of the thyroid gland, border conditions, and changes in blood flow.

Thyroid nuclear scan: no or low thyroid uptake in the early stages is helpful in the diagnosis.

Specialized tests

Thyroid fine-needle aspiration cytology: early typical cytology smear can see multinucleated giant cells, flaky epithelioid cells, different degrees of inflammatory cells can assist in the diagnosis, mainly used in difficult cases to confirm the diagnosis.

Differential diagnosis

Nodular goiter

Similarity: there is cervical goiter.

Differences: history of regional epidemics, usually asymptomatic, only neck goiter, normal thyroid function, ultrasound and cytology can help to differentiate.

Toxic diffuse goiter (Graves’ disease)

Similarities: both have thyrotoxic manifestations, including profuse sweating, excessive eating, increased stool frequency, weight loss, rapid heartbeat, agitation, irritability, and hand tremors.

Differences: longer duration of disease, increased iodine uptake in Graves’ disease on nuclear iodine uptake examination, and rich blood supply and high flow rate in the thyroid gland on ultrasonography.

Thyroid cancer

Similarity: enlarged thyroid gland.

Differences: negative antibody for thyroid cancer, heterogeneous cells on cytologic examination, and histopathologic examination.

Treatment

Treatment principle

Patients with mild symptoms do not need special treatment, and follow-up is sufficient.

Those with obvious symptoms should be treated in time, mainly with medication. Surgery is used when goiter is obvious and pressure symptoms appear or medication is ineffective.

Treatment method

Medication

Medication for thyroiditis depends on the type and symptoms.

Treatment of hyperthyroidism

In case of severe symptoms, beta-blockers (propranolol) are used, which have the effect of lowering the heart rate and reducing tremors.

Avoid antithyroid medications, glucocorticoids, or radioactive 131I therapy during use.

Symptoms of hyperthyroidism are only temporary, and your doctor will slowly reduce the dose of your medication as your symptoms gradually improve.

Hypothyroidism treatment

Replacement therapy with thyroid hormone (levothyroxine sodium tablets) is needed to restore hormone levels in the body and ensure normal metabolism.

During the course of treatment, the dose needs to be gradually adjusted to the appropriate level, and increased or decreased as symptoms change.

Older patients need to have their heart function checked regularly.

Other medications

Antibacterial drugs

Acute thyroiditis requires broad-spectrum antimicrobial therapy.

They can be adjusted to drug-sensitive antimicrobials after the pathogen is identified.

Non-steroidal anti-inflammatory drugs

Can be anti-inflammatory and analgesic.

Suitable for those with mild symptoms.

Commonly used drugs are aspirin, ibuprofen, indomethacin and so on.

Glucocorticoids

Can relieve the inflammatory response and reduce pain.

It can be used if the symptoms are severe with high fever and unbearable localized pain in the thyroid gland.

Subacute thyroiditis in 24 hours after taking the drug, most patients thyroid area pain significantly reduced or disappeared, continue to use the drug for 1 to 2 weeks and then reduce the dosage, the total duration of the drug 6 to 8 weeks or more. Some patients will relapse, can also take prednisone, generally still effective.

Specific drugs need to be selected under the guidance of a physician, not self-medication.

Surgery

Indications for surgery

Surgical resection can be considered for patients with significant, painful thyroid enlargement, tracheal compression, and ineffective medical treatment. Partial resection of the thyroid isthmus or bilateral thyroid glands can be taken.

Acute thyroiditis (septic) and subacute thyroiditis are usually not suitable for surgery.

Chronic thyroiditis also requires a careful decision as to whether it should be surgically removed due to the high probability of hypothyroidism.

Surgical Procedures

Isthmus resection

When tracheal compression is evident, the thyroid isthmus may be removed or incised to relieve symptoms.

If thyroid cancer cannot be ruled out, a biopsy should be performed, and those with confirmed malignancy should be treated as thyroid cancer.

Bilateral partial thyroidectomy

Part of the patient’s thyroid gland can be removed to relieve organ compression caused by goiter.

Postoperative complications include postoperative bleeding, damage to the laryngeal reentrant nerve, and injury or removal of the parathyroid glands, which may also lead to hypothyroidism and require long-term thyroid hormone replacement therapy.

Precautions

If the thyroid gland is obviously enlarged and the disease is of long duration, the removal of part of the heavily enlarged thyroid gland will lead to collapse of the trachea and trigger asphyxia, which will be fatal if tracheal intubation is not carried out in time, and close observation is needed after the operation.

Postoperative thyroid function needs to be checked regularly.

Prognosis

Cure

The prognosis of thyroiditis varies depending on the cause of the disease.

Subacute thyroiditis is a self-limiting disease. Most cases resolve within weeks or months and have a good prognosis.

Hashimoto’s thyroiditis is prone to permanent hypothyroidism due to severe damage to the follicular structure of the thyroid gland and requires lifelong thyroid hormone replacement therapy.

Painless thyroiditis is a temporary, self-limiting disease with no tenderness, and should be followed up annually; some patients may develop permanent hypothyroidism.

Postpartum thyroiditis often resolves spontaneously, with about 80% resolving 6 to 9 months after delivery and the other 20% developing persistent hypothyroidism.

Dangers

Thyroiditis can cause permanent hypothyroidism.

Autoimmune thyroiditis may increase the risk of other autoimmune diseases, such as connective tissue disease, type 1 diabetes, systemic lupus erythematosus, and premature ovarian failure.

Thyroiditis may also induce other diseases such as lymphadenitis, infected thyroglossal cyst, laryngochondritis, anterior cervical cellulitis, retropharyngeal interstitial abscess, chondromalacia thyroiditis, and even cancerous and life-threatening changes.

Daily

Daily Management

Dietary management

Basic Diet

Staple food should be mainly rice and noodles and in sufficient quantity to meet the calories required for body metabolism.

Appropriately increase the intake of high quality protein such as milk, eggs, lean meat (beef, etc.) and soybean products.

Eat more fresh fruits and vegetables, such as tomatoes, spinach, strawberries, apples and oranges.

Points to note for hyperthyroidism

Try to consume non-iodized salt and eat iodine-rich foods such as kelp, marine fish and nori in small amounts to ensure the synthesis of thyroid hormones.

Reduce the intake of foods with high fiber content such as celery and sweet potato to reduce the frequency of bowel movements.

Prohibit the intake of stimulating foods and beverages, such as strong tea and coffee, to avoid mental excitement.

Eat more food rich in calcium, phosphorus and other minerals such as yogurt, cheese and nuts as appropriate, and sunbathe more to prevent osteoporosis; for those with low blood potassium level, eat more apples and bananas.

Drink more water, drink 2,000 to 3,000 milliliters of water every day to replenish the water lost from sweating, diarrhea, and accelerated respiration, etc. However, people with concurrent heart diseases should avoid drinking a lot of water to prevent aggravating edema and causing heart failure.

Points of attention for hypothyroidism

Control fat intake, do not eat fatty meat, fried chicken and other high-fat food.

Consume beef, animal liver and animal blood appropriately to supplement iron and improve anemia.

Eat iodine-rich foods such as kelp and nori in moderation, or use iodized table salt, but be careful to control salt intake.

Exercise management

Adhere to exercise, if there is no other abnormality, perform moderate-intensity exercise for 150 minutes per week, with an average of 30 minutes per day, to strengthen the body’s immunity.

Medication Management

When taking thyroxine, you should seek medical advice if you experience polyphagia and lethargy, pulse >100 beats/min, weight loss, fever, profuse sweating, and agitation.

Thyroxine is usually taken 30 to 60 minutes before breakfast.

When taking more than 2 medications, there should be an appropriate interval of 30 minutes.

Follow the doctor’s instructions for medication and do not reduce or stop the medication on your own to minimize the recurrence of the disease.

Others

Regularly defecate every day and develop the habit of regular defecation.

Pay attention to keep warm, prevent respiratory tract infection and reduce the occurrence of colds.

Follow-up and review

Raise awareness of the disease and go to the hospital for review when any discomfort occurs, which will help detect the disease in time.

Thyroid function should be checked regularly.

Prevention

Avoid iodine deficiency or excessive iodine intake.

Adopt a regular routine, get enough sleep and be in a good mood, which is conducive to improving the body’s resistance.

Exercise and do more aerobic exercise to maintain good health.

Use drugs that may cause thyroiditis, such as amiodarone and interferon, with caution under the guidance of a doctor.

Actively treat autoimmune diseases.

When using radioactive iodine to treat hyperthyroidism or using radiation therapy to treat certain cancers, ask your doctor in detail about the risk of thyroiditis and take precautions.

Have regular physical examinations to detect abnormalities in time for early diagnosis and treatment.