Diabetic Dermopathy
Diabetic dermopathy (DD), commonly known as shin spots, refers to the red-brown, atrophic, circinate macules and patches that often appear on the lower extremities in patients with T2DM. Although the pretibial area is the most frequently involved site, other areas of bony prominence such as the forearms can be affected. The prevalence of DD in the diabetic population can be exceedingly high, with some studies reporting incidence rates greater than 50%, particularly in those with poorly controlled T2DM.[19,20,21] Interestingly, DD also has been documented in patients without T2DM and has been postulated to be an early sign of insulin resistance.[20,22]
The pathogenesis of DD remains uncertain, but one proposed mechanism is through microvascular damage caused by hyperglycemia-induced, nonenzymatic glycation, possibly in conjunction with mild trauma, that leads to the deposition of hemosiderin and melanin in the skin.[20,23] A recent study identified increased vascularization of dermopathy lesions when compared with surrounding tissue.[24] Subcutaneous nerve ischemia and degeneration secondary to diabetic neuropathy also have been postulated as causative.[20,23] Given the lack of effective therapies and the asymptomatic nature of DD, treatment typically is not pursued. However, DD is associated with other diabetic microvascular complications, including diabetic nephropathy, retinopathy, and neuropathy. For this reason, identification of DD warrants further characterization and management of a patient’s underlying diabetes.[19,20]
Cutis. 2021;107(2):74-78. © 2021 Cutis
