Mucopolysaccharide content of skin in patients with pretibial myxedema.

It is well-known that the skin of patients with primary and secondary myxedema contains a mucinous infiltrate. This extracellular deposition of metachromatically staining material has been interpreted as being a complex of acid mucopolysaccharide and protein (1). It has not been defined chemically. The infiltrate disappears from the skin of patients with generalized myxedema who are given 120 to 180 mg. of desiccated thyroid daily for six to eight weeks (1). A deposit, histochemically like that which occurs in generalized myxedema, occasionally presents locally in the pretibial skin of patients with thyrotoxicosis and exophthalmos (2, 3). Whenthe patient with localized pretibial myxedema is given 180 mg. of desiccated thyroid a day, however, no clinical or histochemical change occurs in the myxedematous plaque. In 1947 Watson and Pearce isolated a crude mucopolysaccharide fraction from the pretibial plaques of two patients with pretibial myxedema. They found considerably less of this material in skin from the amputated leg of an elderly man (4). Wehave found no record of the comparison of chemical or histochemical findings of myxedematous areas to other areas of the skin of patients with pretibial myxedema, or comparison with control patients of similar age. Wewish to report a chemical study of the mucopolysaccharide concentration of the skin of six euthyroid patients with pretibial myxedema and exophthalmos and eight patients of comparable