Definition. – A constitutional disease, characterized by thickening and induration of the skin and subcutaneous tissue and progressive failure of bodily and mental powers, and caused by the atrophy or ablation of the thyroid gland.
Symptoms. – The first skin manifestations appear upon the face, giving it a swollen, thickened, edematous appearance, the so-called “moon-face”. The swollen tissue is firm, does not pit upon pressure, is not influenced by position and has a yellow, waxy color, while the surface is dry and anemic. Occasionally on the extremities it may be livid. The hair falls out, especially if the axillary and pubic regions are involved. The disease usually extends to the neck and extremities and less commonly to other parts of the body. With its extension there develops a feebleness of body and mind that may increase to incoordination, unsteadiness of gait and imbecility.
Etiology and Pathology. – While the condition may occur in either sex or at any age, it is most common in middle-aged women. The real cause is obscure, although it is admitted that it is concerned with the atrophy and loss of the thyroid gland. Clinical observation has demonstrated this fact because the pathogenesis of the disease is very like that of sporadic cretinism, in which a congenital deficiency of the thyroid gland has been found. Myxedema has followed the partial or complete removal of the thyroid gland in a number of cases. Ord states that there is a mucous degeneration of the subcutaneous fat and infiltration of the cutis with mucin. Hun observes that there is a general atheromatous endarteritis, and Charcot considers the implication of the nervous system as the primary factor.
Diagnosis – Dropsical swellings pit on pressure and are associated with the renal or cardiac disease which causes them. Acromegaly can be excluded in the absence of the enlargement of the bones, chiefly of the hands and feet.
Prognosis and Treatment. – While this condition is persistent, chronic and progressive, and if untreated or neglected usually has a fatal ending, the discovery of the value of thyroid extract has much improved the prognosis. “Thyroid feeding” consists in the use of the desiccated or powdered glands given in capsule or tablet form. The dose should be small at first, one grain three times daily, and gradually increased up to five grain doses, if needed, or if symptoms of thyroidism (rapid pulse, shortness of breath, restlessness, etc.) do not appear. Usually relief from the symptomatic condition is prompt and fairly complete in a few weeks. But it is only relief, and the effect must be kept up by smaller or less frequent doses of the thyroid for months or years and perhaps throughout the life of the patient. If thyroid treatment needs to be discontinued, an indicated constitutional remedy such as Calcarea carb., Calcarea fluor., or Hydrocotyle may be used.