Eosinophilic fasciitis

In this low-power, trichrome-stained skin and fascial biopsy, the epidermis (far left) and dermis appear to be normal in width, and the dermis shows a loose arrangement of collagen. By contrast, the subcutaneous fascia (right side) is markedly thickened and shows dense blue staining with trichrome, indicative of extensive collagen accumulation.