Subacute de Quervain's thyroiditis.

Subacute de Quervain's thyroiditis, or granulomatous thyroiditis, is one of the most common forms of the disease.

An increase in the incidence of diseases is noted in the autumn-winter period. Women are ill 4 times more often than men, the age of patients may vary, but the greatest number of cases occurs at 30-40 years of age.

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Causes subacute de Quervain's thyroiditis.

After measles, infectious mumps, adenovirus diseases, the number of cases of subacute thyroiditis increases. It develops 3-6 weeks after viral infections. Penetrating into the cell, the virus causes the formation of atypical proteins, to which the body reacts with an inflammatory reaction.

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Pathogenesis

De Quervain's thyroiditis is accompanied by symmetrical or asymmetrical enlargement of the gland. Its tissue is dense, dull on section, and of non-uniform structure. Microscopically, numerous granulomas are detected, formed by giant and pseudo-giant cells (clusters of histiocytes surrounding colloid drops), colloid spilled from follicles, macrophages, neutrophils, and eosinophils. Follicles in the areas of granuloma formation are destroyed, and the epithelium is desquamated and necrotic.

In the interstitial tissue around and between granulomas there is mucoid edema and lymphoid infiltration, including plasma cells; macrophages, eosinophils, and mast cells are found. In the intact follicles, the cells show signs of increased functional activity, and the basement membrane is thickened. Sometimes granulomas suppurate with the formation of microabscesses. Over time, pronounced fibrosis of the stroma with lime deposition is observed, as well as regenerative processes: new formation of follicles in islets from the interfollicular epithelium and cells of destroyed follicles.

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Symptoms subacute de Quervain's thyroiditis.

There is an acute feeling of malaise, pain in the neck area radiating to the ear, increasing with swallowing and movement. The body temperature rises to 38-39 °C, but may also be subfebrile. The gland increases in size (with diffuse damage), a feeling of pressure on the front surface of the neck appears, weakness, sweating, nervousness, and general malaise increase. From the first days of the disease, a rapidly increasing ESR is noted in the clinical blood test - up to 60-80 mm/h (in some cases up to 100 mm/h) - with a normal or slightly increased content of leukocytes without changes in the blood formula.

The course of the disease can be divided into several stages, during which there are different laboratory test results. Thus, in the first, acute stage (lasting 1-1.5 months), there is an increased content of alpha2-globulins, fibrinogen and thyroid hormones in the blood with reduced uptake of the iodine isotope by the gland. Clinically, symptoms of thyrotoxicosis are observed. Such dissonance between the scanning data and clinical symptoms is explained by the fact that the inflamed gland loses the ability to fix iodine; previously synthesized hormones and thyroglobulin enter the blood due to increased vascular permeability against the background of inflammation. After 4-5 weeks, the disruption of hormone synthesis leads to normalization of their level in the blood, and then to a decrease.

The pain in the gland decreases and remains only on palpation. ESR is still increased, the content of alpha2-globulins and fibrinogen remains elevated. A decrease in the level of thyroxine and triiodothyronine activates the release of thyroid-stimulating hormone by the pituitary gland and an increase in the uptake of the iodine isotope by the thyroid gland. Approximately by the end of the 4th month from the onset of the disease, the absorption of ¹³¹ 1 may be increased with moderate clinical symptoms, dry skin. These phenomena pass on their own, as the function of the gland is restored and the recovery stage begins. The size of the gland is normalized, pain disappears, ESR decreases, T4, T3 and TSH indicators return to normal. With a spontaneous course, this takes 6-8 months, but the disease is prone to relapse, especially under the influence of unfavorable factors (hypothermia, fatigue, repeated viral infections).

Diagnostics subacute de Quervain's thyroiditis.

The diagnosis of subacute de Quervain's thyroiditis is based on anamnestic data, clinical symptoms, increased ESR with normal blood count, low absorption of ¹³¹ 1 by the thyroid gland with a simultaneous high content of thyroid hormones in the blood, the presence of giant multinucleated cells in puncture biopsy, and a good effect of glucocorticoid treatment. With the use of thyroid ultrasound, when specific structural changes are observed (echo-negative zones without clear boundaries, disappearing against the background of anti-inflammatory therapy after 4-6 weeks), puncture biopsy is rarely used. Scanning is used only if malignancy is suspected.

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Differential diagnosis

Depending on the stage of subacute thyroiditis, differential diagnosis is carried out with various diseases. First, it is necessary to differentiate from acute purulent thyroiditis, carefully find out from the patient data on previous diseases, keeping in mind that viral thyroiditis occurs much more often than purulent. Extremely increased ESR with normal leukocyte content without changes in the blood formula, an increase in the level of alpha2-globulins and fibrinogen are characteristic of subacute thyroiditis. The lack of effect from antibiotic treatment for 5-7 days is an additional argument in favor of this disease.

In case of a smoothed onset of the disease, without a pronounced rise in body temperature and pain in the gland, the patient may consult a doctor only at the stage of hyperthyroidism, and it is necessary to differentiate thyroiditis from the initial form of diffuse toxic goiter. In diffuse toxic goiter, the clinical picture of thyrotoxicosis coincides with increased absorption of the isotope by the gland, high levels of thyroid hormones in the blood and low levels of thyroid-stimulating hormone. In thyroiditis, high levels of hormones in the blood are accompanied by low uptake of the isotope and normal or reduced levels of TSH.

In case of clinical symptoms of hypothyroidism, it is necessary to exclude autoimmune thyroiditis. This helps to determine the classic antithyroid bodies, the detection of which in high titers is characteristic of this disease. In subacute thyroiditis, antibodies to thyroglobulin are sometimes detected in titers not exceeding several hundred. Low levels of thyroid hormones in the blood coincide with high levels of TSH and low absorption of the isotope by the gland in autoimmune thyroiditis. In subacute thyroiditis, an elevated level of TSH is accompanied by increased absorption of I (in the recovery stage). Puncture biopsy is also indicated: characteristic morphological changes allow for a more precise diagnosis.

In focal and focal subacute thyroiditis, a section of the gland lobe is affected, which is determined as a painful compaction upon palpation. This form of thyroiditis should be differentiated from carcinoma. In both diseases, the clinical symptoms (pain, irradiation points, size, density) do not allow even a tentative diagnosis (anamnestic data on a previous viral infection can be a valuable addition). Of the additional research methods, it is necessary to point out indirect lymphography of the thyroid gland, when a contrast agent is injected into the lower poles of the lobes with the patient in an upright position.

After 60 minutes, the gland is contrasted. Radiography of thyroiditis is characterized by a change in the structure of the gland pattern, which takes the form of coarse granules and torn trabeculae. Regional lymph nodes in thyroiditis are contrasted after 24 hours, while in carcinoma, the lymph nodes are blocked. According to S. Yu. Serpukhovitin, thyroid lymphography data coincide with the results of histological examination in 93% of cases. Puncture biopsy is also indicated, regarding which there is no consensus.

However, most authors are supporters of this diagnostic method. A specific marker of thyroid carcinomas is an elevated level of thyroglobulin in the blood. But the method for determining it is not available everywhere (in medullary carcinoma, such a marker is a high level of calcitonin in the blood). In case of technical difficulties, diagnostic treatment with glucocorticoids can be recommended: the lack of effect within 2 weeks when taking 40-60 mg of prednisolone per day speaks against the inflammatory genesis of the compaction in the gland, the patient is indicated for a puncture biopsy.

Treatment subacute de Quervain's thyroiditis.

Treatment of subacute thyroiditis is conservative. Prescription of antibiotics is pathogenetically unfounded. The fastest effect is achieved by prescribing glucocorticoids in doses of their optimal anti-inflammatory action: 30-40 mg of prednisolone per day. The duration of treatment is determined by the time it takes to normalize the ESR and eliminate the pain syndrome. As practice has shown, prescribing the drug every other day is less effective, and a relatively short course of treatment (1.5-2 months) does not disrupt the normal relationship between the pituitary gland and the adrenal glands of the patient, and no manifestations of adrenal insufficiency are observed with gradual withdrawal of the drug. Doses of glucocorticoids are reduced under the control of ESR. If it accelerates, it is necessary to return to the previous dose. Instead of glucocorticoids, salicylic or pyrazolidone drugs are indicated. Their use together with glucocorticoids is not justified because the ulcerogenic effect of these substances on the gastric mucosa is summed up, and the anti-inflammatory effect of glucocorticoids is greater than that of salicylates. The use of mercazolil in the hyperthyroid phase is inappropriate, since thyrotoxicosis is caused by the accelerated entry of previously synthesized hormones into the blood, and mercazolil reduces their formation.

It is recommended to prescribe beta-blockers, which eliminate tachycardia and promote the peripheral transition of T4 to the inactive, reverse form of T3. The dose of beta-blockers usually ranges from 40 to 120 mg/day, the duration of treatment is about a month. The administration of thyroid hormones when their level in the blood decreases is indicated only in the presence of pronounced clinical symptoms of hypothyroidism, the daily dose usually does not exceed 0.1 g of thyroidin, the duration of treatment is 3-4 weeks.

The disease tends to recur, and the duration of glucocorticoid treatment sometimes reaches 4-6 months. In this case, patients may develop symptoms of glucocorticoid overdose: weight gain, face rounding, stretch marks, increased blood pressure, hyperglycemia. If glucocorticoid therapy cannot be stopped within 6-8 months, surgical treatment is indicated - resection of the corresponding lobe of the gland.

Therapy can be carried out with salicylates alone at a dose of 2.5-3 g/day. However, the effect is achieved more slowly than with glucocorticoids. A mandatory condition for the use of salicylates is their uniform distribution throughout the day.

If the result is positive, the dose of glucocorticoids is reduced to the minimum maintenance dose (usually 10 mg of prednisolone per day), then naprosyn, aspirin or reopyrin are added, and prednisolone is reduced to 1/2 tablet every three days.

Forecast

Subacute de Quervain's thyroiditis has a favorable prognosis. Patients' ability to work is usually restored within 1.5-2 months. Outpatient observation for 2 years from the onset of the disease.