Myxedema

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Myxoedema
Classification and external resources
Hyaluronan.png
Hyaluronan, an example of a mucopolysaccharide.
ICD-10E03.9
ICD-9244.9
DiseasesDB6558
MedlinePlus000353
eMedicinemed/1581 derm/347
MeSHD009230
 
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Myxoedema
Classification and external resources
Hyaluronan.png
Hyaluronan, an example of a mucopolysaccharide.
ICD-10E03.9
ICD-9244.9
DiseasesDB6558
MedlinePlus000353
eMedicinemed/1581 derm/347
MeSHD009230
This article is about skin changes that occur in hypothyroidism. The word myxoedema was historically used to refer hypothyroidism in general. For the related medical emergency, see myxedema coma.

Myxedema (British English: Myxoedema) is a term used synonymously with severe hypothyroidism. It is also to describe a dermatological change that can occur in hypothyroidism, and some forms of hyperthyroidism. This article discusses the dermatological changes.

In this context, myxoedema refers to mucopolysaccharides deposition in the dermis. This results in swelling of the affected area. One manifestation of myxoedema occurring in the lower limb is pretibial myxedema, a hallmark of Graves disease. Myxoedema can occur in Hashimoto's thyroiditis and other long-standing forms of hypothyroidism, as well as Graves disease, an autoimmune form of hyperthyroidism.

The word myxoedema originates from μύξα, taken from ancient Greek to convey 'mucus' or 'slimy substance' and ὁίδημα for swelling.

Signs and symptoms[edit]

Man with myxedema or severe hypothyroidism showing an expressionless face, puffiness around the eyes and pallor
Additional finding include swelling of the arms and legs and significant ascites.

Myxoedema can occur in the lower leg (pretibial myxedema) and behind the eyes (exophthalmos).

Cause[edit]

Myxoedema is known to occur in various forms of hypothyroidism, and also in Graves' disease. One of the hallmarks of Grave's disease is pretibial myxedema, myxoedema of the lower limb.[1]

Myxoedema is more common in women than in men.[2]

Myxedema can occur in:

Pathophysiology[edit]

Myxedema describes a specific form of cutaneous and dermal edema secondary to increased deposition of connective tissue components. These can include glycosaminoglycans, hyaluronic acid, and other mucopolysaccharides. [4] The increased deposition of glycosaminoglycan is not fully understood, however two mechanisms predominate:

References[edit]

  1. ^ Berger, William D. James, Dirk M. Elston, Timothy G. Andrews' Diseases of the skin : clinical dermatology. (11th ed. ed.). [London]: Saunders/ Elsevier. ISBN 978-1-4377-0314-6. 
  2. ^ Schneider, Arthur S.; Kim, Philip A. Szanto ; with special contributions by Sandra I.; Swanson, Todd A. (2009). Pathology (4th ed. ed.). Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins. p. 314. ISBN 1451109067. 
  3. ^ "Pretibial Myxedema", Retrieved on 2009-3-27
  4. ^ Berger, William D. James, Dirk M. Elston, Timothy G. Andrews' Diseases of the skin : clinical dermatology. (11th ed. ed.). [London]: Saunders/ Elsevier. ISBN 978-1-4377-0314-6.