BI05 Erythrodermic crusted scabies in an immunosuppressed patient contributing to a fatal outcome

Abstract

Erythroderma is a dermatological emergency regardless of the underlying cause and is associated with significant systemic morbidity, including hypothermia, dehydration and sepsis. We report a fatal case of erythrodermic crusted scabies in an immuno­suppressed patient, initially presumed to represent Stevens–Johnson syndrome/toxic epidermal necrolysis (SJS/TEN). A 71-year-old woman with a history of antineutrophil cytoplasmic antibody-associated vasculitis on long-term immunosuppression (methotrexate and rituximab) was brought in by ambulance with progressive lethargy, confusion and a rapidly worsening extensive skin rash. She was profoundly unwell with hypothermia (27.6 °C), bradycardia and hypotension, requiring intubation and admission to the intensive care unit (ICU). Initial investigations and clinical assessment in a peripheral hospital supported a diagnosis of profound septic shock with presumed SJS. Blood cultures grew Gram-negative organisms, and computed tomography demonstrated bilateral bronchopneumonia. The referring hospital sought dermatology input due to concern for SJS. Images of the cutaneous eruption sent to the dermatology on-call service were strongly suggestive of SJS/TEN, leading to an expedited ICU-to-ICU transfer for specialist dermatological evaluation. Further history obtained from the patient’s general practitioner revealed a prolonged pruritic eruption treated repeatedly as scabies and later on suspected to represent psoriasis. Dermatological examination demonstrated erythroderma with extensive thick yellow crusting involving the hands, feet, genitalia and scalp, a negative Nikolsky sign, and no mucosal involvement. The clinical findings were not in keeping with SJS. Urgent skin biopsy and scrapings confirmed scabies infestation and excluded SJS. Despite appropriate antiparasitic treatment and cutaneous improvement, the patient died from severe sepsis. This case highlights the critical importance of face-to-face dermatological assessment. While clinical photographs are valuable triage tools, they may be misleading and should not replace direct examination and comprehensive history taking. It is unclear whether crusted scabies was the primary source of sepsis in this case; however, this patient’s erythroderma contributed significantly to systemic decompensation, hypothermia and an overall poor outcome.