What is Thyroiditis?

Thyroiditis (thyroiditis) is a heterogeneous disease involving the thyroid caused by various reasons. The etiology is different, the clinical manifestations and prognosis are quite different, thyroid function can be normal, hyperthyroidism, and regression, and sometimes three kinds of abnormalities can occur during the course of disease, and some patients eventually develop permanent hypothyroidism. According to the course of disease, it is divided into acute (purulent), subacute (non-purulent) and chronic. Divided according to the cause of infection, autoimmune, radiation thyroiditis and so on. Among them, autoimmune thyroiditis is the most common and can be divided into Hashimoto's thyroiditis (that is, chronic lymphocytic thyroiditis), atrophic thyroiditis, painless thyroiditis, and postpartum thyroiditis. The following mainly discusses several common thyroiditis.

Basic Information

English name

thyroiditis

Visiting department

Endocrinology

Common locations

thyroid

Common symptoms

May have different manifestations such as fear of cold and fatigue, or fear of heat and irritability

Contagious

no

Causes of thyroiditis

Autoimmune, viral infection, bacterial infection, fungal infection, chronic sclerosis, radiation injury, granulomas, drugs, trauma and other reasons are all related to the onset of thyroiditis. Staphylococcus, streptococcus, pneumococcus and other bacterial infections can cause acute thyroiditis. Thyroid virus infections such as coxsackie virus, mumps virus, influenza virus, and adenovirus infections are considered to be the cause of subacute thyroiditis and can also occur after non-viral infections (such as Q fever or malaria, etc.). In addition, genetic susceptibility and environmental factors are also related to the pathogenesis of autoimmune thyroid.

Clinical manifestations of thyroiditis

Hashimoto's thyroiditis

That is, chronic lymphocytic thyroiditis, the age of high incidence is 30 to 50 years old, the incidence rate of women is 15 to 20 times that of men. Onset is slow, with goiter during onset, hard and tough texture, nodular surface, clear borders, often with pharyngeal discomfort or mild hypopharyngeal difficulty, some patients may have compression symptoms. There is often no special sensation in the early stage, thyroid function can be normal, a few patients may be accompanied by transient hyperthyroidism in the early stage, and most cases have already found hypothyroidism. Patients often suffer from cold, edema, fatigue, dry skin, bloating, constipation, irregular menstruation, and decreased libido. A few patients may develop thyroid-related eye disease. In some patients, Hashimoto's thyroiditis and Graves disease coexist, and the clinical manifestations of hyperthyroidism and hypothyroidism appear alternately.

2. Subacute thyroiditis

The disease is self-limiting and is the most common thyroid pain disease. It occurs in middle-aged women aged 30 to 50 years. The typical manifestation is severe thyroid pain, which usually begins on one side of the thyroid gland, and then radiates to other parts of the gland and the roots and jaw of the ear. It is often accompanied by general discomfort, fatigue, muscle pain, and fever. It peaked in 3 to 4 days, and subsided within 1 week. Many patients had slow onset. After 1 to 2 weeks, the fluctuation of the condition continued for 3 to 6 weeks. After improvement, there may be multiple relapses within a few months. The volume is increased by 2 to 3 times or more than normal, and tenderness is obvious on contact. Within 1 week after the onset, about half of the patients were accompanied by symptoms of hyperthyroidism, such as excitement, heat, panic, tremors, and sweating. These symptoms are caused by the excessive release of thyroid hormone from the thyroid during acute inflammation. During the resolution of the disease, a small number of patients may show signs of reduced thyroid function such as swelling, constipation, fear of cold, and drowsiness, but these symptoms do not last for a long time, and eventually thyroid function returns to normal.

3. Painless thyroiditis

Onset can occur at any age, more common in women aged 30 to 50 years. Typical thyroid function changes are divided into three stages: thyrotoxicosis, hypothyroidism, and recovery. Thyroidemia is characterized by sudden onset of nervousness, fear of heat, tachycardia, and weight loss. In some cases, hypothyroidism is the clinical manifestation because the onset of thyroid toxin is not obvious. The hypothyroidism period gradually returns to normal after 2-9 months. Some patients have persistent hypothyroidism, and 10% to 15% of patients can relapse after 10 years. About half of the patients developed mild thyroid enlargement with diffuse, hard texture, no nodules, no pain and tenderness.

4. Postpartum thyroiditis

Occurred within one year after delivery. The patient's thyroid gland may be mild to moderately swollen, of medium texture and without tenderness. Typical clinical course is bipolar hyperthyroidism. Hyperthyroidism occurs within six months after delivery and lasts for 1 to 2 months. It is manifested as palpitations, emotional excitement, fear of heat, and fatigue. A hypothyroidism occurs 3 to 8 months after delivery and lasts 4 to 6 months. It is manifested by fatigue, inattention, constipation, and pain in muscles and joints. The recovery period occurs 6 to 12 months after delivery, and about 20% of patients can leave persistent hypothyroidism.

Thyroiditis examination

Hashimoto's thyroiditis

Thyroid autoantibodies TgAb (thyroglobulin antibody) and TPOAb (thyroid peroxidase antibody) significantly increased titers are one of the characteristics of this disease. Before the onset of hypothyroidism early, positive antibodies were the only basis for diagnosing the disease. During subclinical hypothyroidism, TSH (thyrotropin) levels increased slightly, and T ₄ (thyroxine) and T ₃ (triiodothyronine) levels were normal. When it develops into dominant hypothyroidism, the levels of T ₄ and T ₃ decrease, and the level of TSH significantly increases. Alternating course of hyperthyroidism and hypothyroidism may occur in some patients. Thyroid ultrasonography showed weakened, uneven, diffuse changes within the thyroid. Thyroid iodine uptake and thyroid isotope scans are not specific for the diagnosis. FANC (Thin Thyroid Aspiration and Cytological Examination) tests are rarely used in the diagnosis of this disease, but they have a confirmatory value and are mainly used to distinguish them from diseases such as nodular goiter.

2. Subacute thyroiditis

Blood tests showed a marked increase in erythrocyte sedimentation, an increase in white blood cell count, and an increase in C-reactive protein. During the thyrotoxicosis period, the serum T ₄ and T ₃ levels increased, and the thyroid iodine uptake rate decreased (usually less than 2%). The serum T ₃ / T ₄ ratio is often <20. T ₄ and T ₃ concentrations decreased and TSH levels increased during hypothyroidism. The indicators of the recovery period gradually returned to normal. Thyroid-associated antibodies were negative or low in titer throughout the course of the disease. Ultrasound examination showed mild, moderate diffuse enlargement of the thyroid gland, uneven internal echo, hypoechoic or non-echoic area, and color Doppler blood flow imaging showed a decrease or disappearance of blood flow signals in the hypoechoic or non-echoic area.

3. Painless thyroiditis

Serum T ₄ and T ₃ increased during the thyroid stage, T ₃ / T ₄ ratio was less than 20, and thyroid iodine uptake was less than 3%. Thyroid hormone decreased during hypothyroidism; T ₄ , T ₃ and thyroid iodine uptake gradually returned to normal during the recovery period. TgAb and TPOAb are positive in more than half of the patients, and the increase of TPOAb is often more obvious. FANC examination showed lymphocyte infiltration.

4. Postpartum thyroiditis

The characteristic manifestation of the laboratory test of hyperthyroidism is the "two-way separation" between serum thyroid hormone levels and thyroid iodine uptake, that is, serum T ₄ and T ₃ levels increase, and thyroid iodine uptake decreases significantly. The TSH level gradually decreased during T1 and T4 and T3 decreased. Thyroid hormone levels and thyroid iodine uptake gradually returned to normal during the recovery period. Ultrasound examination showed hypoechoic or hypoechoic nodules.

Thyroiditis diagnosis

Diagnosis can be made based on medical history, clinical symptoms, goiter and other signs, combined with laboratory test results of serum thyroid hormone levels, thyroid iodine uptake, and thyroid autoantibodies. Should be distinguished from nodular goiter, Graves disease, thyroid cancer.

Thyroiditis treatment

Hashimoto's thyroiditis

Patients with mild goiter who are asymptomatic may not be treated and should be followed up. When the thyroid is significantly enlarged or has reduced thyroid function, even if only serum TSH increases, thyroid preparations should be given. If the goiter is rapidly enlarged, or accompanied by pain, or has compression symptoms, glucocorticoids can be used for short-term treatment. Hashimoto's hyperthyroidism should be treated with low-dose antithyroid drugs. Generally, iodine and surgery are not used to prevent severe hypothyroidism.

2. Subacute thyroiditis

Mainly symptomatic treatment, reducing inflammation and pain. Mild patients do not need treatment. Those with obvious symptoms should use acetylsalicylic acid and non-steroidal anti-inflammatory drugs to relieve the symptoms. Corticosteroids are recommended for more severe and prolonged cases, and all symptoms disappear within 24 to 48 hours. When the thyroid radioiodine uptake returns to normal, treatment is terminated. -receptor blockers can be used in patients with obvious symptoms of thyroid toxicity, and no antithyroid drug treatment is required. When permanent hypothyroidism occurs, long-term replacement therapy is required.

3. Painless thyroiditis

Symptoms of thyroidism are generally treated symptomatically. -receptor blockers are used to alleviate thyrotoxicosis. Routine use of glucocorticoids is not required, and antithyroid drugs and radioactive iodine treatment are avoided. Continuous hypothyroidism with thyroid hormone replacement therapy, most patients can return to normal, thyroid hormone dose needs to be adjusted until discontinuation.

4. Postpartum thyroiditis

Patients with severe hyperthyroidism can be given symptomatic treatment, such as beta-blockers, without the need for antithyroid drugs. A hypothyroidism serum TSH <10mIU / L does not require thyroid hormone replacement therapy and can recover on its own. TSH should be monitored annually thereafter, and once hypothyroidism occurs, treatment should be timely.