Scleredema Diabeticorum Mimicking Systemic Sclerosis in a 75-Year-Old Female: A Case Report.

Scleredema diabeticorum is a rare sclerosing cutaneous disorder characterized by diffuse, nonpitting, woody skin induration, most commonly occurring in patients with long-standing diabetes mellitus. Its clinical resemblance to systemic sclerosis (SSc) may result in diagnostic confusion, particularly in atypical presentations. We report a 75-year-old woman with a 20-year history of insulin-dependent Type 2 diabetes mellitus who developed progressive, generalized skin thickening. The disease initially involved the lower extremities and subsequently progressed proximally to the trunk, upper limbs, and face, with prominent facial and periorbital involvement and sparing of the hands and feet. She was initially suspected to have SSc because of diffuse skin induration and positive antinuclear antibodies and was treated with corticosteroids. However, the absence of characteristic distal scleroderma features, negative SSc-specific antibody testing, and histopathological findings of marked dermal thickening with broad collagen bundles and mucin deposition supported a diagnosis of scleredema diabeticorum. Management was complicated by diabetic nephropathy and concurrent cardiac disease, requiring individualized immunomodulatory therapy, close monitoring, and optimization of glycemic control. UVA1 phototherapy was attempted but discontinued because of immediate clinical intolerance. The patient subsequently received systemic immunomodulatory treatment with clinical improvement during follow-up. This case highlights the importance of distinguishing scleredema diabeticorum from SSc, particularly when atypical clinical features and positive nonspecific autoantibodies may lead to diagnostic uncertainty. Careful clinical assessment, appropriate serological evaluation, and histopathology are essential for accurate diagnosis and management.