Images of Hyperthyroidism: Pretibial Myxedema

Swelling of the lower legs broughtthis 57-year-old woman to a familypractice clinic. She had a history ofhyperthyroidism with weight loss,tachycardia, and anxiety. This conditionwas confirmed with blood testsand radioactive iodine uptake testing.Pretibial myxedema is a classicfinding in hyperthyroidism that mayappear years before or after developmentof the endocrine disorder. Thedistinguishing feature is nonpittingedema of mucinous ground substanceon the anterior surface of thelower leg. In the early stages, theoverlying skin is erythematous andpruritic. These symptoms usuallysubside spontaneously over a periodof months or years, but topical corticosteroidsmay be given to relieve thepruritus.