Pretibial myxedema (thyroid dermopathy)

Editorial Perspective: Pretibial myxedema (thyroid dermopathy) is the sine qua non of the dermatologic manifestations of thyroid disease. Although any medical student can reflexively state that pretibial myxedema is a hallmark of Graves disease, how many clinicians realize that the term is a misnomer? That thyroid dermopathy is not necessarily limited to the pretibial region and is not exclusively seen in patients with Graves disease are just two facts frequently misconceived about this condition. The reality is that much has been learned about the immunologic pathogenesis of thyroid der-mopathy, a condition that results from the accumulation of the glycosaminoglycans, hyaluronic acid, and chondroitin sulfate in the dermis. A precise understanding of its pathogenesis, however, remains to be determined. This chapter surveys the clinical, biological, and therapeutic landscape of thyroid dermopathy. By understanding its natural history, eliminating or reducing predisposing factors such as smoking and obesity, appreciating the complexities of the immunologic aberrations leading to mucin deposition, and having a logical approach to therapy, clinicians should be able to at least ameliorate this chronic, occasionally severe, recalcitrant disorder.