Rash and fever in a kidney transplant recipient

Abstract

A 59-year-old man was admitted to the hospital with a 2-day history of rash and high fever. He reported malaise and myalgia but denied itchiness and respiratory, gastrointestinal, and urinary symptoms. He had received a living-donor kidney transplant 6 years previously; his primary renal disease was IgA nephropathy. His past medical history included hypertension, diverticular disease, and osteopenia. Two months prior to this presentation, he experienced acute allograft dysfunction due to intragraft posttransplant lymphoproliferative disorder (PTLD) with associated Epstein–Barr virus (EBV) viremia. The allograft dysfunction had resolved with valganciclovir treatment. Tacrolimus and mycophenolate mofetil were stopped and prednisolone (10 mg daily) was commenced as the sole immunosuppressive agent. EBV had then become undetectable by polymerase chain reaction (PCR). Two weeks prior to the current presentation, azathioprine (50 mg daily) was added to his immunosuppressive regimen. Other medications included ramipril and vitamin D. On examination, his heart rate was 108 bpm and his blood pressure was 140/86 mmHg. His temperature was 40°C/104°F. No focal infective signs were present, and no lymphadenopathy was detected. The renal graft was nontender on palpation. He had a rash (Figure 1) localized to the chest, abdomen, back, and legs. The neck, face, scalp, and mucous membranes were unaffected. Blood tests revealed stable allograft function (a creatinine level of 1.5 mg/dL), a C-reactive protein level of 350 mg/L, and a white blood cell count of 13.2 × 109/L with 90% neutrophils. Other hematological and biochemical parameters were within normal limits, and chest radiograph was normal. Urinalysis demonstrated protein + only. Multiple blood cultures were negative for bacterial and fungal growth. 1What is the most appropriate initial investigation?aComputed tomography (CT) scan of the chest, abdomen, and pelvisbSerum IgA titercRenal allograft biopsydSkin biopsyeVaricella zoster virus (VZV) PCR2What does the skin biopsy light microscopy (Figure 2) show?aEpidermal keratinocyte necrosisbEpidermal thickeningcIgA deposition in superficial capillariesdLeukocytoclastic vasculitiseNeutrophilic folliculitis3What is the diagnosis?aAzathioprine hypersensitivity syndromebHenoch–Schönlein purpuracPTLDdSweet’s syndromeeVZV infection4What is the best course of management?aStart acyclovirbStart broad-spectrum antibioticscStart high-dose corticosteroidsdStart plasma exchangeeStop azathioprine