This patient has clinical features of pretibial myxedema, generally seen in patients with Graves hyperthyroidism. Also termed thyroid dermopathy, pretibial myxedema results from the accumulation of glycosaminoglycans in the dermis that leads to the characteristic thickening and development of firm but compressible plaques described in this patient. The pretibial thickening generally occurs 1 to 2 years after the onset of Graves hyperthyroidism. The mechanisms of development of both pretibial myxedema and Graves ophthalmopathy are similar, and the findings often develop within a year of one another. The mechanisms of pretibial myxedema are not well understood but may be related to the interaction of thyrotropin-receptor antibodies with antigen-specific T cells and dermal fibroblasts causing inflammation and increased glycosaminoglycan production. Similar to increasing the risk for ocular disease, tobacco use may also increase the risk for pretibial myxedema in patients with Graves disease; almost all patients with pretibial myxedema have evidence of ophthalmopathy. The skin lesions typically occur on the shins, but rarely may occur elsewhere. Some patients may develop elephantiasis and severe leg deformity from the extent of myxedema. Once the lesions occur, they tend to persist regardless of the status of the thyroid disease. Skin-directed therapy may be required for improvement, although the lesions are generally of cosmetic concern and do not pose health risks.

Lipodermatosclerosis is a severe form of stasis in which the skin becomes thickened and may develop an “inverted champagne bottle” appearance with the skin on the distal legs being very tight and “woody.”

Necrobiosis lipoidica (NL) is another skin manifestation of an endocrine condition that can occur on the anterior shins. NL presents as atrophic, orange-colored patches often associated with visible vasculature from skin thinning; the lesions may ulcerate. NL may develop in patients with diabetes mellitus, and when present may be a sign of end-organ damage, as patients with NL are more likely to have retinopathy or nephropathy.

Stasis dermatitis occurs in the setting of lower extremity edema. It is characterized by a ruddy-brown complexion in the setting of chronic venous backup and fluid filling the legs in response to proximal compression. This is typically seen in patients with heart failure.