Abstract

We present a case of a 40-year-old hospitalized male with a history of type 1 diabetes, end-stage renal disease on dialysis, and heart failure who was admitted for swelling of the face with concern for SVC syndrome. Dermatology was consulted for a pruritic and painful rash located on the extremities which had been present for approximately 2 months. Physical examination revealed hyperpigmented, firm papules and nodules with keratotic plugs and central dells on the bilateral upper and lower extremities. Clinical presentation was most consistent with acquired perforating dermatosis in the setting of the patient's ESRD and poorly controlled diabetes. The differential diagnosis also included prurigo nodularis from constant scratching and less likely an infectious etiology. A punch biopsy was performed and sent for hematoxylin and eosin staining. Histological sections demonstrated epidermal invagination centrally with parakeratosis and neutrophilic debris. Within this space, there was extrusion of underlying dermal collagen fibers. Within the dermis, a perivascular lymphocytic infiltrate and upward streaking collagen was observed. The histopathologic findings were consistent with the clinical impression of a perforating dermatosis. However, within the dermis at the base of the keratotic papule were fibers that appeared to be branching hyphae. To further investigate a fungal etiology, a PAS was performed which was negative for fungal elements. Movat and elastic statins revealed the hyphal-like fibers were elastic fibers. To our knowledge, this interesting histopathologic finding has not been previously reported in the literature. It is important to be able to distinguish between fungal elements and their mimickers to guide appropriate treatment.

Financial Disclosure:
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