Preradial myxedema in thyroid disease

Abstract

Patients with Graves' disease were noted to have thickening of the skin on the extensor surfaces of their forearms. Skin biopsy specimens were obtained from nine consecutive patients with Graves' disease treated with sodium iodide I 131, from three patients with other thyroid disorders, and from one patient with acromegaly. Skin specimens from one patient with scleredema and one patient with scleromyxedema were used as controls for the histologic stains. Hematoxylin-eosin-stained sections of forearm skin from eight of nine patients with Graves' disease showed prominent round-cell (probably lymphocytic) infiltration around dermal capillaries and distortion of collagen fibers. In five of the patients with Graves' disease, staining with Mowry's colloidal iron disclosed dense deposits of mucin in the papillary dermis, with a distribution similar to that reported for pretibial myxedema. Mucopolysaccharide deposition in the skin on the extensor surface of the forearms may be the clinical counterpart of pretibial myxedema.

Observing pretibial myxedema in patients with Graves' disease using digital infrared thermal imaging and high-resolution ultrasonography: for better records, early detection, and further investigation

“…In other words, the prevalence of dermopathy may be higher than 0.5-4.3% among patients with GD. In a study of forearm skin biopsy of nine patients with GD without PM, dense mucin deposition in the papillary dermis was noted in five patients (22). The authors suggested that deposition of mucopolysaccharide was a widespread phenomenon in GD, and that clinical PM represented changes at a later stage of the disease, which correlated with our study and hypothesis.…”

Thyroid Autoimmunity in Patients with Skin Disorders

“…Less common is an elephantiasis nostras variant in which the extremity becomes enlarged and covered with verrucous nodules [10]. Thickening of the skin of the extensor surface of the forearm (preradial myxedema) has been reported [18]. Excessive amounts of hyaluronic acid and chondriotin are present in lesions as well as in clinically normal skin [19].…”

The Fibroblast Is the Target Cell in the Connective Tissue Manifestations of Graves' Disease

“…These unusual sites of thyroid dermopathy generally occur following trauma to the area [23]. In addition, as noted above, excess GAG was shown to be present in clinically unaffected forearm skin from 7 o f 10 patients with Graves' hyperthyroidism [27], It may be that there is generalized autoimmune involvement o f connective tissue throughout the body in Graves' disease. Also in support of this concept is the demonstration, dis cussed above, that patients' orbital T cells recognize autolo gous skin fibroblasts, as well as orbital fibroblasts [18].…”

“…It is usually seen in patients who have both GO and PTD [24], As in GO, GAG accumulation and fibroblast pro liferation is characteristic of affected tissues in PTD and acropachy [23], Approximately 90% of patients with GO have a current or past history of hyperthyroidism, and a majority of the re mainder have laboratory evidence o f autoimmune thyroid disease [25], Conversely, although only approximately 25-50% of patients with hyperthyroidism have clinically evi dent GO, most of these patients have evidence of ocular in volvement when sensitive imaging techniques are used [26], In a similar manner, although PTD occurs in only a few percent of patients with Graves' hyperthyroidism and in approximately 15% of patients with GO, 90% of patients with PTD have a current or past history of hyperthyroidism, and 99% have GO [24]. Forearm skin biopsies in 7 of 10 hyperthyroid patients with no clinical evidence of PTD show histologic evidence of dermopathy [27], Finally, acro pachy occurs in 7% of patients with PTD [24] and has not been described in patients without PTD. These data suggest that there is overlapping, if not concurrent, subtle evidence of hyperthyroidism, GO and PTD (and perhaps acropachy) in the vast majority of patients with Graves' disease.…”