Myxedema - Causes, Symptoms, Diagnosis and Treatment

Myxedema is an endocrine disease that develops with a decrease or complete cessation of thyroid hormones entering the blood. It is an extreme, clinically pronounced form of hypothyroidism. It is characterized by mucous edema of the skin and subcutaneous tissue, most noticeable on the face and neck. Puffiness is manifested by swelling of the chin and the area around the eyes, voice changes, unintelligible speech, narrowing of the nasal passages, cough, shortness of breath. The diagnosis is established by the results of examination, blood tests for T4, T3 and TSH, ultrasound and radioisotope examination of the thyroid gland (thyroid gland). Treatment is based on hormone replacement therapy.

General information

Synonymous names of myxedema are mucosal edema, myxedematous edema. Since the disease is caused by hypothyroidism, its prevalence is higher in regions with iodine deficiency. Epidemiology is also uneven among different age groups, women are most susceptible to myxedema during menopausal restructuring of the body. The incidence rate in this category of the population is 5-10 times higher than in the general population. Among patients with thyroid diseases in women, myxedema is diagnosed in 2-2.5% of cases, in men - in 0.2% of cases. In children, pathology can be congenital or acquired, accompanied by a delay in mental and physical development.

Causes of myxedema

Hypothyroidism is a factor in the formation of myxedematous edema. At the initial stages, it does not cause structural changes in organs, with adequate therapy it is fully compensated. In the absence of treatment, the disorders become irreversible, patients need lifelong medication. Taking into account the etiological sign , there are four types of myxedema:

1 Primary. It is based on primary hypothyroidism - hormone deficiency caused by a decrease in thyroid functions. The disease occurs after operations on the organ, as a result of exposure to radiation, with Hashimoto's thyroiditis, infiltration diseases of the gland, deficiency or overabundance of iodine.

2 Secondary. Pathology is provoked by hypothyroidism, which has developed on the basis of disorders of the pituitary gland or hypothalamus. These glands are responsible for the production of thyrotropin and thyrotropin-releasing hormone, which control the secretion of thyroxine, triiodothyronine. The immediate cause of myxedema may be Simmonds' disease, pangypopituitarism.

3 Pretibial. This type of disease is radically different from the previous ones – it is caused not by a deficiency, but by an excess of iodine-containing hormones. The cause of the formation is a multi-node toxic goiter.

4 Idiopathic. In some cases, the etiology of edema remains unknown. Patients retain the normal size and functionality of the thyroid gland, hormones are secreted in the required amount with a reduced reaction of tissues and organs.

Pathogenesis

With a long-term deficiency of iodized hormones, protein synthesis slows down, their decay processes intensify. Albumins, hyaluronic acid and other mucopolysaccharides that are hydrophilic and retain water in tissues accumulate in the intercellular space. A large amount of liquid binds to the tissue colloid, a mucin – mucus-like compound is formed. Its accumulation is externally manifested by thickening of tissues - edema. With an excess of mucin in the internal organs, their sizes increase, blood microcirculation is disrupted, dystrophic processes develop in the tissues. Against the background of a reduced level of T4 and T3, the activity of antidiuretic hormone increases, which aggravates swelling, since the hormone enhances the process of reabsorption of non-concentrated urine in the kidney ducts, thereby reducing the volume of secondary urine and retaining fluid inside the body.

Symptoms of myxedema

The key symptom is swelling of the subcutaneous tissue and skin. When pressed, the shape and color of the skin do not change, redness, paleness, indentations or prints do not remain. Puffiness is most pronounced on the neck and face, with severe course it spreads to the whole body. The face becomes puffy, masklike. His features are coarsened, the chin area increases in size, facial expressions are simplified. The mouth is constantly ajar, nasal breathing is disturbed due to swelling of the nasal mucosa. Due to the swelling of the vocal cords, the voice becomes rough, hoarseness, hoarseness, cough appear. Patients suffer from shortness of breath.

The symptoms of mucosal edema are combined with the clinical picture of hypothyroidism. Patients are sluggish, sleepy, slow, sedentary. They feel chilly, they do not tolerate being outside in the cold season, they often freeze at home, especially when they remain motionless. Muscle weakness, slowness of movements and thought processes are characteristic - difficulties in concentration and switching attention, memorizing information. Patients are in a depressed or subdepressive state, crying, losing interest in what is happening. Chest pains, headaches and muscle pains are often noted. Appetite is reduced, the digestive process is slowed down, constipation often occurs.

In childhood, myxedema leads to a delay in mental, physical and sexual development. The earlier the disease began, the more pronounced the deviations. With a congenital form of myxedema, cretinism is diagnosed. Limbs are deformed, the formation of teeth is disrupted, their eruption and replacement are delayed. The swelling of the tissues of the head creates a "caricature", roughness of facial features: the nose is flat and wide, the eyes are deep and wide set, the tongue is enlarged, falls out of the mouth. The intellectual defect is moderate or deep, in severe cases there is no speech and self-service skills.

Pretibial myxedema, which develops with thyrotoxicosis, is manifested by local symptoms. The skin of the shins thickens, has a rough surface, acquires a reddish-bluish hue. There are signs of excessive keratinization. In the affected areas, hair follicles increase, hair falls out intensively, itching increases. Thyrotoxicosis causes the presence of tachycardia, pain and discomfort in the heart, muscle weakness, increased irritability, anxiety, distraction, tremor. Appetite often increases, weight decreases.

Complications

Severe course of myxedema can lead to the development of myxedematous coma. The elderly and elderly people, patients with long-term hypothyroidism, who have suffered acute infections, hypothermia or intoxication are at increased risk. The comatose state is manifested by severe hypothermia, slowing of breathing and pulse, sudden arterial hypotension, acute intestinal obstruction and urinary retention, confusion, heart failure. Death occurs in 80% of cases.

Diagnostics

Examination of patients with suspected myxedema is carried out by an endocrinologist. During the clinical survey, patients complain of drowsiness, chilliness, weakness, decreased performance, dry skin, headaches. Objectively, there is swelling of the face, neck and limbs, pallor, nasal breathing disorders, shortness of breath, hypothermia, bradycardia, arterial hypotension. The face is evenly puffy, the eye slits are narrowed, the contours of the face are smoothed, paradoxically bright blush on the cheeks is possible. To confirm the diagnosis of myxedema and its differentiation with renal, hepatic and adrenal insufficiency, syndrome of inadequate secretion of ADH, syndrome of idiopathic edema, instrumental and laboratory studies are carried out:

• General, biochemical blood tests. There is an increased content of proteins, lipoproteins and cholesterol, a reduced level of iodine, inorganic phosphorus, hemoglobin (hypochromic anemia), an increased number of lymphocytes and eosinophils. ESR is often higher than normal.
• The study of hormones in the blood. A pathognomonic sign of hypothyroidism is a low level of total and free thyroxine (T4), triiodothyronine (T3). An increased concentration of thyroid-stimulating hormone indicates primary hypothyroidism, a reduced concentration indicates secondary hypothyroidism.
• Thyroid scintigraphy. When studying the activity of glandular tissue, weak absorption of radioactive iodine is observed. The insufficiency of the total capture of the drug reveals a decrease in the functionality of cells. By the uniformity of the glow, the presence of ectopic areas, nodular formations is estimated.
• Ultrasound of the thyroid gland. Ultrasound examination allows you to visualize the structure and size of the organ. The procedure is performed to detect or confirm the absence of neoplasms as factors of myxedema - nodes, tumors, calcifications. Hypothyroidism is characterized by a reduced volume of gland tissue.

Treatment of myxedema

The main direction of therapy is etiotropic, aimed at eliminating the cause of myxedematous edema (hypothyroidism). Hormone replacement drugs normalize the level of thyroid hormones. In order to improve the well-being of patients in a short time, to improve their quality of life, supportive treatment is carried out. With an integrated approach , patients are prescribed:

• Hormone replacement therapy. Preparations of thyroid hormones - thyroxine, triiodothyronine - are widely used in endocrinology to compensate for hypothyroid conditions. Since in most cases the thyroid gland loses its ability to heal itself, therapy is lifelong. The effectiveness assessment is carried out 1-1.5 months after the start of the course, then once every 6-12 months.
• Glucocorticoid drugs. With pretibial myxedema, the presence of inflammatory and autoimmune processes, glucocorticosteroids are used. Medicines of this group have anti-inflammatory and immunosuppressive effects, suppress the activity of autoantibodies. Improvement of well-being is noted from the first days of treatment.
• Diet. All patients are shown a diet with a limited salt and fat content. This helps to reduce puffiness, normalize the concentration of cholesterol and lipoproteins. In cases where myxedema is provoked by iodine-deficient hypothyroidism, a diet is prepared with products rich in iodine - seaweed, seafood, nuts. Additionally, iodine-containing food additives are prescribed.
• Symptomatic therapy. To reduce puffiness, diuretics and diuretic herbal preparations are used, it is recommended to wear compression underwear. In the presence of severe cardiovascular disorders, correctors of the functional state of the myocardium, cardiotonic and antiarrhythmic agents, nootropics are necessary.

Prognosis and prevention

Myxedema is characterized by a slow increase in symptoms, so timely diagnosis and adequate therapy can maintain a benign course of the disease while maintaining a high quality of life for patients. In the congenital form of the disease, the prognosis is ambiguous. Preventive methods include the correct treatment of hypothyroidism, periodic monitoring of hormone levels, consultations and examinations by an endocrinologist. People who have a hereditary burden, who live in iodine-deficient regions, who have been exposed to radiation, need routine ultrasound of the gland. Women during pregnancy and menopause are recommended to take iodine-containing supplements.