Renal histological findings in a patient with acute renal injury associated with purpura fulminans: a case report

ABSTRACT Introduction: Purpura fulminans (PF) is a rapid progressive thrombotic disease in which hemorrhagic infarction of the skin and disseminated intravascular coagulation (DIC) occurs. It can potentially cause acute kidney injury (AKI). However, there is no description in the medical literature of renal histological findings of PF. Case report: A 20-year-old female patient, previously healthy, was admitted to the emergency department (ED) with odynophagia, fever, generalized myalgia and anuria, which evolved with the appearance of purpuric plaques on the face and limbs. She required dialysis on admission. Laboratorial tests showed anemia, leukocytosis, thrombocytopenia, and elevation of lactic dehydrogenase (LDH). The purpuric lesions became bullous with ruptures and then necrotic and erosive, reaching the dermis, subcutaneous tissue and musculature, until bone exposure. There was no improvement with initial antibiotic therapy aimed at the treatment of meningococcemia. Thrombotic microangiopathy (TMA) and PF were then suspected. The patient remained in daily dialysis, requiring plasmapheresis. After sustained improvement of the thrombocytopenia, she underwent renal biopsy, which was not compatible with TMA, characterizing possible PF. A complete recovery of the renal function was achieved and cutaneous sequels were treated with grafts. Conclusion: When thrombotic and hemorrhagic phenomena overlap, obtaining a renal biopsy can be difficult. However, in the presented case, the biopsy allowed the exclusion of AKI caused by TMA, presenting for the first time, histological findings compatible with PF.

摘要 引言：暴发性紫癜（Purpura fulminans, PF）是一类快速进展的血栓性疾病，可出现皮肤出血性梗死与弥散性血管内凝血（disseminated intravascular coagulation, DIC），并可能引发急性肾损伤（acute kidney injury, AKI）。但目前医学文献中尚未有关于PF肾脏组织学表现的相关报道。病例报告：本例为1例既往健康的20岁女性患者，因吞咽痛、发热、全身性肌痛及无尿就诊于急诊科（emergency department, ED），就诊期间面部与四肢陆续出现紫癜性斑块。患者入院时即需接受透析治疗。实验室检查结果显示贫血、白细胞增多、血小板减少症及乳酸脱氢酶（lactic dehydrogenase, LDH）水平升高。患者的紫癜性皮损逐渐发展为水疱并破溃，随后出现坏死与糜烂，累及真皮、皮下组织及肌肉组织，直至骨暴露。初始针对脑膜炎球菌血症的抗生素治疗未取得明显疗效。临床随后怀疑为血栓性微血管病（thrombotic microangiopathy, TMA）与PF。患者后续每日接受透析治疗，并需进行血浆置换。待血小板减少症持续改善后，患者接受了肾活检，结果不符合血栓性微血管病的表现，提示可能为PF。患者肾功能完全恢复，皮肤后遗症通过植皮手术进行治疗。结论：当血栓性与出血性表现叠加时，肾活检的操作难度较大。但在本例中，肾活检成功排除了血栓性微血管病所致的急性肾损伤，首次报道了与PF相符的肾脏组织学表现。