Pretibial myxedema

A skin condition associated with thyroid disease

Pretibial myxedema

Pretibial myxedema showing characteristic skin changes.

Pretibial myxedema is a form of myxedema that occurs in the skin, particularly over the shins. It is most commonly associated with Graves' disease, an autoimmune disorder that affects the thyroid gland. This condition is characterized by the deposition of mucopolysaccharides in the dermis, leading to a thickening of the skin.

Pathophysiology

Pretibial myxedema is caused by the accumulation of glycosaminoglycans, such as hyaluronic acid, in the dermis. This accumulation is due to the stimulation of fibroblasts by autoantibodies that are also involved in the pathogenesis of Graves' disease. The result is a localized thickening and induration of the skin.

Clinical presentation

The condition typically presents as non-pitting edema and thickening of the skin over the anterior aspect of the lower legs. The affected skin may appear waxy, and in some cases, it can have a peau d'orange (orange peel) texture. The lesions are usually bilateral and symmetric.

Diagnosis

Diagnosis of pretibial myxedema is primarily clinical, based on the characteristic appearance of the skin lesions and the presence of thyroid disease. A skin biopsy can be performed to confirm the diagnosis, showing mucin deposition in the dermis.

Treatment

Treatment of pretibial myxedema focuses on managing the underlying thyroid disorder. Topical corticosteroids may be used to reduce inflammation and improve the appearance of the skin. In some cases, compression therapy can be beneficial.

Prognosis

The prognosis of pretibial myxedema varies. In some patients, the condition may improve with treatment of the underlying thyroid disease, while in others, it may persist or progress.

Related pages

• Graves' disease
• Thyroid gland
• Autoimmune disorder
• Myxedema