Iodine hyperthyroidism

Introduction Scientific research believes that hyperthyroidism is an autoimmune disease involving cellular immunity. 80% to 90% of hyperthyroidism patients can detect thyroid stimulating immunoglobulin in serum, inhibiting serum thyrotropin and its receptor or The combination of tissues activates adenylate cyclase, strengthens the function of thyroid cells, stimulates the thyroid gland to stimulate, enhances the thyroid's absorption of iodine and the physiological effects of thyroxine synthesis and secretion, causing hyperthyroidism. Simply stated, hyperthyroidism caused by excessive intake of iodine is called iodothyronidine. It was discovered in the early 19th century that iodine can cause hyperthyroidism, and it was not until 1910 that the name of iodine was found. After the 1930s, endogenous goiter was treated with iodide around the world, and the hyperthyroidism caused by iodine increased. In the four years after Yugoslavia began to promote iodized salt in 1953, patients with hyperthyroidism tripled in order to prevent iodine. The occurrence of hyperthyroidism must first prevent the supply of excessive iodine.

Cause

Iodine is closely related to the thyroid gland. The former is a raw material for the synthesis of thyroid hormone. The daily iodine content of an adult is about 70 g, and the adolescent is 150 to 200 g. The synthesis of thyroid hormone increased with increasing iodine supply in a certain dose range, but the opposite result may occur if the iodine supply exceeds a certain limit (normal 5 mg/d, hyperthyroidism 2 mg/d).

1 In the short-term, large doses of iodine can cause acute inhibition of thyroid hormone release. This inhibitory effect, also known as Woff-Chaikoff effect, may be a temporary protective mechanism to avoid release and synthesis of excessive hormones. This effect is often used to treat hyperthyroidism.

2 Long-term overdose of iodine, the Woff-Chaikoff effect gradually disappears, the so-called "release phenomenon", the synthesis and release of thyroid hormone after escape can return to normal, and even accelerate, sometimes iodothyroidism occurs.

There are two situations in which iodine causes hyperthyroidism:

1 In areas of iodine deficiency, endemic goiter is treated with iodide and accounts for the majority of iodothyroid.

2 In non-iodine-deficient areas, occasionally seen in some patients with non-toxic multinodular goiter. In addition, long-term use of iodine-containing drugs such as amiodarone is also a common cause of iodine-methyl in non-iodine-deficient areas.

an examination

Related inspection

Thyroid 131 iodine absorption rate serum total thyroxine (TT4)

Most of the patients were mild, the symptoms were the same as general hyperthyroidism, mild hyperthyroidism, hard mass, no vascular murmurs and tremors. Typical hyperthyroidism symptoms such as polyphagia, weight loss, aversion to heat, and irritability were observed. Generally, there were no exophthalmos and localized mucus. Edema signs. The serum levels of T3, T4 and rT3 in the laboratory were increased, and the increase in T4 was the most obvious. The thyroid stimulating hormone release (TRH) stimulation test is low or non-responsive. 131 iodine rate was significantly reduced in the thyroid gland, and thyroid imaging was poorly developed.

Hyperthyroidism is particularly sensitive to symptoms such as fear of heat, excessive sweating, agitation, vaginal weight loss, rapid heart rate at rest, special eye signs, and goiter. If vascular murmurs and tremors are found on the thyroid gland, it is more diagnostic.

Differential diagnosis

The following diseases must be considered when differential diagnosis of hyperthyroidism:

1. Simple goiter: Except for goiter, there are no symptoms and signs mentioned above. Although the 131I uptake rate is sometimes increased, the T3 inhibition test mostly shows inhibition. Serum T3, rT3 were normal.

2. Neurosis.

3, autonomous high-function thyroid nodules: radioactivity concentrated in the nodules during scanning, repeated scans after TSH stimulation, visible nodular radioactivity increased.

4. Other:

(1) Tuberculosis and rheumatism often have low fever, hyperhidrosis and tachycardia. People with diarrhea as the main manifestation are often misdiagnosed as chronic colitis.

(2) The performance of senile hyperthyroidism is atypical, often with apathy, anorexia, and obvious weight loss, which is easily misdiagnosed as cancer.

(3) Unilateral invasive exophthalmos need to be differentiated from intraorbital and cranial low tumors.

(4) Hyperthyroidism with muscle disease, need to be identified with familial cycle paralysis and myasthenia gravis.

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