Scleredema of Buschke.

Main text A 46-year-old African-American male with a history of type-1 diabetes (DM) was referred to the Rheumatology clinic for a further evaluation of possible systemic scleroderma. He reported a 3-year history of skin thickening and hyperpigmentation on his back and shoulders. Over the last 12 months, his symptoms progressed, involving the proximal arms, legs, and back with sparing of his hand and feet. His medical history was remarkable for insulin-dependent DM, which was complicated with diabetic retinopathy and peripheral neuropathy. Skin examination revealed a woody, hardened, indurated, hyperpigmented skin with a peau d’orange appearance involving the posterior aspect of the neck, shoulders, arms, legs, and mid-back (Figure 1a, b). The face, chest, forearms, hands, and feet were unaffected. There was no telangiectasia, sclerodactyly, fingertip ulceration, or calcinosis. The remainder of the physical examination was unremarkable. Laboratory evaluation revealed a normal complete blood count, comprehensive metabolic panel, Western sedimentation rate, C-reactive protein, creatine phosphokinase level, aldolase, and thyroid-stimulating hormone. Hemoglobin A1C level was 7.1 (normal <6). Immunofluorescence antinuclear antibodies, complement levels, and Scl-70 were all negative. Serum protein electrophoresis and urine protein electrophoresis were normal. Full thickness skin biopsy revealed a thickened dermis, with fenestrated collagen and mucin deposition in the deep dermis, which is consistent with the diagnosis of scleredema (Figure 2 a–c).