Pruritic papules with keratotic plugs in a patient with end-stage renal disease: Kyrle disease or perforating folliculitis?

Summary: Abstract Body: Kyrle disease and perforating folliculitis are rare perforating dermatoses often associated with systemic conditions like diabetes mellitus and end-stage renal disease (ESRD). Differentiating between these entities poses significant clinical and histopathologic challenges due to overlapping features. A 39-year-old female with past medical history of ESRD (on hemodialysis for 12 years), type 2 diabetes mellitus, hypertension, and prior left leg amputation due to gangrene, presented to the emergency department with a 3-month history of worsening pruritic eruptions and poor glycemic control. Lesions began on her legs and spread to her arms and back. Physical examination revealed numerous flesh-colored papules and nodules with central keratotic plugs, predominantly affecting the legs, arms, and back, with koebnerization on the legs. She was admitted for further management. Histopathology from a punch biopsy of the left forearm demonstrated hyperkeratosis with acute folliculitis and dermal parakeratotic material. Differential diagnoses included perforating folliculitis and Kyrle disease. Elastic staining revealed rare elastic fibers entering the epidermis, consistent with Kyrle disease. However, the absence of elastic fibers in the mid to upper epidermis and cornified layer introduced diagnostic uncertainty. This case highlights the diagnostic complexity of perforating dermatoses in patients with systemic comorbidities, emphasizing the importance of integrating clinical, histopathologic, and advanced staining techniques for accurate diagnosis. Recognizing and addressing perforating dermatoses in ESRD patients is critical to improving management and outcomes. Future studies are warranted to refine diagnostic criteria and elucidate pathogenesis. Leila Parsa¹, Taha Rasul¹, Leo Wan², Angelia Stepien² 1. Department of Dermatology, HCA Orange Park Hospital, Orange Park, FL, United States. 2. Department of Dermatology, West Virginia School of Osteopathic Medicine, Lewisburg, WV, United States. Clinical Research: Epidemiology and Observational Research