myxedema(redirected from pretibial myxedema)
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myxedema(mĭksədē`mə), condition associated with severe hypothyroidism and lack of thyroid hormone in the adult. In the child it is known as cretinismcretinism
, condition produced in infants and children due to lack of thyroid hormone. It usually results from a congenital defect (e.g., absence of the thyroid, presence of only a rudimentary gland, inability of the gland to produce thyroxine).
..... Click the link for more information. . Symptoms include a dry swelling of the skin, slowed speech and mental awareness, deepened voice, intolerance to cold, fatigue and weakness, and nonspecific degeneration of the heart. Most cases result from atrophy of the thyroid from unknown causes, although surgical removal or irradiation of the gland also precipitates the disorder. Myxedema is treated by administering synthetic preparations of thyroxine (thryoid hormone), liothyronine (triiiodothyronine), a combination of the two synthetic hormones, and desicated animal thyroid.
a disease caused by thyroid insufficiency (hypothyroidism) or complete thyroid failure. Thyroid and hypothalamic-pituitary myxedema are differentiated.
Thyroid myxedema may be congenital—resulting from abnormal intrauterine development, toxicoses of pregnancy, or intrauterine infection (syphilis, viral infections)—or acquired—resulting from injury or acute or chronic inflammation of the thyroid gland. This form of myxedema may also result from an autoimmune reaction against the body’s own thyroglobulin. Hypothalamic-pituitary myxedema is due to functional and organic changes that interfere with the production of the TSH-releasing factor of the hypothalamus or the thyrotropic hormone of the pituitary.
The main symptoms of myxedema are mucous edema of the skin and subcutaneous tissue, dry skin, sluggishness, drowsiness, poor memory, physical and mental lassitude, lowered basal metabolism, constant sensitivity to cold, lowered blood pressure, slow pulse, and intestinal sluggishness causing constipation. Myxedematous children suffer from dwarfism, slow bone growth, late eruption of the teeth, brittleness of nails, and mental disorders. Treatment includes the regular administration of thyroid preparations (thyroidin) and triiodothyronine.
REFERENCESBaranov, V. G. Bolezni endokrinnoi sistemy i obmena veshchestv. [Leningrad] 1955.
Tareev, E. M. Vnutrennie bolezni, 3rd ed. Moscow, 1957.
Mnogotomnoe rukovodstvo po patologicheskoi fiziologii, vol. 4. Moscow . Pages 228–29.
L. M. GOL’BER