myxedema

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myxedema

 [mik″sĕ-de´mah]
a condition resulting from advanced hypothyroidism, or deficiency of thyroxine; it is the adult form of the disease whose congenital form is known as cretinism. adj., adj myxedem´atous.

Myxedema may be caused by lack of iodine in the diet; by atrophy, surgical removal, or a disorder of the thyroid gland; by destruction of the gland by radioactive iodine; or by deficient excretion of thyrotropin by the pituitary gland. It is marked primarily by a growing puffiness or “sogginess” of the skin, nonpitting edema, abnormal deposits of mucin in the skin, and distinctive facial changes such as swollen lips and a thickened nose.

Because thyroxine plays such an important role in the body's metabolism, lack of this hormone seriously upsets the balance of body processes. Among the symptoms associated with myxedema are excessive fatigue and drowsiness, headaches, weight gain, dryness of the skin, sensitivity to cold, and increasing thinness and brittleness of the nails. In women, menstrual bleeding may become irregular. Medical tests reveal slow tendon reflexes, low blood iodine, below-normal metabolism, and abnormal uptake of radioactive iodine by the thyroid.

The body's defenses against infection also are weakened. If the patient has heart disease, it may worsen. Upset of the functions of the adrenal glands may become critical. In time, if myxedema is not brought under control, progressive mental deterioration may result in a psychosis marked by paranoid delusions.

Myxedema is treated by administration of thyroid extract or similar synthetic preparations. If treatment is begun soon after the symptoms appear, recovery may be complete. Delayed or interrupted treatment may mean permanent deterioration. In most instances, treatment with thyroid hormones or synthetics must be continued throughout the patient's lifetime.
pretibial myxedema localized skin lesions associated with preceding hyperthyroidism, found most often on the front of the legs. It is almost always associated with graves' disease, occurring in 0.5 to 5 per cent of patients. Called also thyroid dermopathy.

myx·e·de·ma

(miks'e-dē'mă), [MIM*255900]
Hypothyroidism characterized by a relatively hard edema of subcutaneous tissue, with increased content of mucins (proteoglycans) in the interstitial fluid; characterized by somnolence, slow mentation, dryness and loss of hair, increased fluid in body cavities such as the pericardial sac, subnormal temperature, hoarseness, muscle weakness, and slow return of a muscle to the neutral position after a tendon jerk; usually caused by removal or loss of functioning thyroid tissue.
[myx- + G. oidēma, swelling]

myxedema

/myx·ede·ma/ (-sĕ-de´mah) a dry, waxy type of swelling (nonpitting edema) with abnormal deposits of mucin in the skin (mucinosis) and other tissues, associated with hypothyroidism; the facial changes are distinctive, with swollen lips and thickened nose.myxedem´atous
congenital myxedema  cretinism.
papular myxedema  lichen myxedematosus.
pituitary myxedema  that due to deficient secretion of the pituitary hormone thyrotropin.
pretibial myxedema  localized edema associated with preceding hyperthyroidism and exophthalmos, occurring typically on the anterior (pretibial) surface of the legs, the mucin deposits appearing as both plaques and papules.

myxedema

or

myxoedema

(mĭk′sĭ-dē′mə)
n.
A disease caused by decreased activity of the thyroid gland in adults and characterized by dry skin, swellings around the lips and nose, mental deterioration, and a subnormal basal metabolic rate.

myx′e·dem′a·tous (-dĕm′ə-təs, -dē′mə-), myx′e·dem′ic (-dĕm′ĭk) adj.

myxedema

[mik′sədē′mə]
Etymology: Gk, myxa, mucus, oidema, swelling
the most severe form of hypothyroidism. It is characterized by swelling of the hands, face, feet, and periorbital tissues and may lead to coma and death. Also spelled myxoedema. See also hypothyroidism.
enlarge picture
Myxedema facies

myxedema

Endocrinology Severe hypothyroidism characterized by yellowish discoloration, nonpitting edema, especially facial, accompanied by periorbital puffiness, puffy lips, and tongue, hoarse voice and sluggish movement; myxedema elicits several reactions a sui generis
Myxedema
Myxedema coma A complication of severe hypothyroidism, characterized by a loss of consciousness, which may be iatrogenic–sedatives in hypothyroidism are very slowly metabolized, may be due to infections or cold exposure; or rarely, occurring spontaneously Mortality 20-50%
Myxedema madness A condition most common in the elderly, characterized by impaired hearing and memory, acalculia, somnolence, psychologic withdrawal, and paranoia
Myxedema megacolon Pseudo-obstruction due to ↓ GI motility
Myxedema wit Confabulation or use of humorous non-sequiturs by a hypothyroid Pt in order to draw the interviewer's attention away from the Pt's impaired memory  

myx·e·de·ma

(miks'ĕ-dē'mă)
Nonpitting waxy edema of the skin, often most pronounced in the face and shins (pretibial myxedema), owing to subcutaneous deposition of mucoid material in hypothyroidism.
Synonym(s): myxoedema.
[myx- + G. oidēma, swelling]

Myxedema

A condition that can result from a thyroid gland that produces too little of its hormone. In addition to a decreased metabolic rate, symptoms may include anemia, slow speech, an enlarged tongue, puffiness of the face and hands, loss of hair, coarse and thickened skin, and sensitivity to cold.

myx·e·de·ma

(miks'ĕ-dē'mă) [MIM*255900]
Hypothyroidism with a relatively hard edema of subcutaneous tissue, with increased content of mucins (proteoglycans) in the interstitial fluid; characterized by somnolence, slow mentation, dryness and loss of hair, increased fluid in body cavities such as the pericardial sac, subnormal temperature, hoarseness, muscle weakness, and slow return of a muscle to the neutral position after a tendon jerk.
Synonym(s): myxoedema.
[myx- + G. oidēma, swelling]

myxedema (mīksədē´mə),

myxedema

a mucinous degeneration with thickening of the skin that occurs in hypothyroidism. In animals it occurs mainly in newborn piglets and dogs.