Myxedema

Myxedema is a term used synonymously with severe hypothyroidism. However, the term is also used to describe a dermatological change that can occur in hypothyroidism and some forms of hyperthyroidism. In this latter sense, myxedema refers to deposition of mucopolysaccharides in the dermis, which results in swelling of the affected area. One manifestation of myxedema occurring in the lower limb is pretibial myxedema, a hallmark of Graves disease, an autoimmune form of hyperthyroidism. Myxedema can also occur in Hashimoto's thyroiditis and other long-standing forms of hypothyroidism. Myxedema is a term used synonymously with severe hypothyroidism. However, the term is also used to describe a dermatological change that can occur in hypothyroidism and some forms of hyperthyroidism. In this latter sense, myxedema refers to deposition of mucopolysaccharides in the dermis, which results in swelling of the affected area. One manifestation of myxedema occurring in the lower limb is pretibial myxedema, a hallmark of Graves disease, an autoimmune form of hyperthyroidism. Myxedema can also occur in Hashimoto's thyroiditis and other long-standing forms of hypothyroidism. The word myxedema originates from μύξα, taken from ancient Greek to convey 'mucus' or 'slimy substance', and ὁοίδημα for 'swelling'. It can also be thought as nonpitting edema, in contrast to pitting edema. Myxedema can occur in the lower leg (pretibial myxedema) and behind the eyes (exophthalmos).