BI29 Crusted scabies: a complicated course in a renal transplant recipient

Abstract A 55-year-old man of Nigerian origin was admitted with a 3-month history of a generalized rash that was intensely pruritic at night. He had received a renal transplant 1 year prior for end-stage kidney disease in the context of hypertensive nephropathy. His maintenance immunosuppressive regimen includes mycophenolate mofetil, tacrolimus and prednisolone. No household contacts were affected by itch. He had been treated with the topical scabicide permethrin cream in the community, resulting in a painful fissuring of the lower limbs that prompted presentation to the emergency department. Full skin examination revealed an extensive scaling eruption, with profuse skin shedding and lichenified fissuring of the lower limbs. There were also loosely adherent, grey, hyperkeratotic scaling plaques widely extending from the genitals to mid-thigh and posterior upper limbs, with involvement of the ear lobes. There was relative sparing of the acral areas. He was initially treated empirically with oral ivermectin, oral flucloxacillin and topical clobetasol propionate ointment and paraffin gel. A full blood count revealed a prominent eosinophilia. A punch biopsy later revealed a number of scabies mites. He was prescribed ivermectin as per the Centers for Disease Control guidelines for crusted scabies in immunosuppressed populations with oral ivermectin 200 μg kg–1 on days 1, 2, 8, 9, 15, 22 and 29. Supply issues in the community delayed his treatment course. Further topical antiscabietic therapy was deferred until tolerated. He was subsequently re-admitted with methicillin-sensitive Staphylococcus aureus bacteraemia with pyelonephritis of the transplant kidney. The prescribed treatment regime of oral ivermectin, a topical keratolytic cream and topical permethrin cream daily for 7 days was completed as an inpatient. This yielded complete resolution of his crusted lesions. He responded well to a prolonged course of intravenous flucloxacillin. This case illustrates the challenge of diagnosing scabies in richly pigmented skin, as well in the immunosuppressed host (in this case due to defective T-cell responses). Maintaining a high index of suspicion is essential in the context of unexplained itch in the immunosuppressed as they may present with atypical presentations. Such vigilance will improve the recognition and management of this uncommon, potentially life-threatening infectious complication of crusted scabies in the transplant population (Wang MK, Chin-Yee B, Lo CKL et al. Crusted scabies in a renal transplant recipient treated with daily ivermectin: a case report and literature review. Transpl Infect Dis 2019; 21:e13077).