Myxedema

Last revised by Daniel J Bell on 18 Sep 2020

Myxedema refers to a waxy swelling of the skin classically seen in hypothyroidism.

Occasionally myxedema is also used as a synonym for hypothyroidism or as a shortening for myxedema coma.

Historically the term myxedema has also been used for a localized form of skin thickening, especially of the shins (hence pretibial myxedema), seen in some forms of hyperthyroidism, especially Graves disease. This has been renamed and is now properly known as thyroid dermopathy 3.

Typically the edema is non-pitting in nature (cf. pitting edema of congestive cardiac failure).

Pathologically, myxedema is due to a number of interrelated processes 3:

  • accumulation of glycosaminoglycans, primarily hyaluronic acid, which due to its highly polar nature, may attract more than 1000 times its own weight in water
  • mucin deposition
  • escape of albumin into the extracellular space
  • poor lymphatic drainage

Myxedema is derived from Greek roots. 'Myxo' comes from the Greek word μυξα (myxa) meaning mucus, and 'edema' from the Greek word οιδημα (oidema) meaning swelling 1,2.

ADVERTISEMENT: Supporters see fewer/no ads

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.