Images of Hyperthyroidism: Pretibial Myxedema

Swelling of the lower legs brought this 57-year-old woman to a family practice clinic. She had a history of hyperthyroidism with weight loss, tachycardia, and anxiety. This condition was confirmed with blood tests and radioactive iodine uptake testing. Pretibial myxedema is a classic finding in hyperthyroidism that may appear years before or after development of the endocrine disorder. The distinguishing feature is nonpitting edema of mucinous ground substance on the anterior surface of the lower leg. In the early stages, the overlying skin is erythematous and pruritic. These symptoms usually subside spontaneously over a period of months or years, but topical corticosteroids may be given to relieve the pruritus.