
Thryoid Acropachy
An Unusual Feature of Graves' Disease and Related Disorders
Thyroid acropachy is characterized by soft tissue swelling and periosteal bone changes, which usually occur in the fingers, toes and lower extremities, causing clubbing.
Thyroid acropachy is as extreme manifestation of autoimmune thyroid disease that causes soft tissue swelling and clubbing primarily in the fingers, toes, and lower extremities. Usually associated with pretibial myxedema, thyroid acropachy is usually only seen in patients with moderate to severe thyroid eye disease.
Who is Affected?
Women are affected about 4 times as often as men. Although not all cases are reported or diagnosed, reports in the scientific literature estimate that about one percent of all patients with thyroid eye disease are affected with thyroid acropachy and about 20 percent of patients with pretibial myxedema may develop acropachy. Thyroid acropachy has been known to occur up to 30 years after the initial diagnosis of Graves’ disease, and it is more likely to be seen in patients treated with radioiodine ablation for hyperthyroidism and in smokers.
Most patients with acropachy have an initial diagnosis of Graves’ disease although acropachy may also occur in patients with Hashimoto’s thyroiditis and euthyroid Graves’ disease. Rarely, acropachy may develop before the emergence of thyroid disease, thyroid eye disease, or pretibial myxedema emerge.
Symptoms
Acropachy is primarily seen in patients with severe forms of pretibial myxedema, a disorder that it may be confused with. However, in acropachy soft tissue swelling is the prominent feature compared to skin lesions in pretibial myxedema. The tissue swelling in acropachy may also cause a periosteal reaction (increased growth of new bone caused by increased collagen or increased production of the subperiosteal bone layer) of the distal phalangeal bones, and rarely articular manifestations of the distal joints. Joint pain is sometimes noted.
Clubbing or thickening of the upper extremity of the fingers or toes with thickening of the skin over the digits is frequently seen in acropachy. The nails in acropachy may also have characteristic changes, particularly clubbing or a spoon-shaped appearance.
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