近期不明原因儿童急性重症肝炎病例在全球多发，自苏格兰首次病例报道至今，已有33个国家通报了至少650例散发病例，相互间缺乏流行病学联系。患儿主要表现为急性肝炎。结合流行病学分析及临床表现初步推论，该疾患可能由感染所致。所有病例均排除甲、乙、丙、丁和戊型肝炎，实验室检测发现半数以上患儿人腺病毒(human adenovirus，HAdV)阳性，部分鉴定为HAdV-41型，提示腺病毒与此疾患发病存在关联性。主流病因推测并提出腺病毒基因重组、辅助因素诱导病毒嗜性改变假说，尤其是超抗原假说引发了广泛热议，即HAdV-41感染诱发严重急性呼吸综合征冠状病毒2(severe acute respiratory syndrome coronavirus 2，SARS-CoV-2)超抗原介导中毒性休克及肝细胞凋亡的发生。最终病因至今尚未明确。本文从流行病学调查、病因分析、病理表现、实验室检查、病原学检测、诊疗规范、现行病例隔离管理及预防消毒措施等方面对本疾患相关信息进行更新，以期总结对本病发病机制及诊疗的最新认识。

Recently, severe acute hepatitis with unknown etiology in children (SAHUEC) was emerging around the world. Since the first case was found in Scotland, at least 650 cases have been reported in 33 countries. The cases were sporadic, and few appeared to have an epidemiological link. Most children presented as acute hepatitis. In concerning an epidemiological pattern and clinical symptoms, the disease has been considered as an infection with unknown pathogen. Hepatitis A, B, C, D and E were excluded in all cases. Laboratory tests found that more than half of the children were positive for human adenovirus (HAdV), and HAdV-41 was identified in a portion of the cases, suggesting that there was an etiologic link between HAdV infection and SAHUEC. Currently two hypotheses are convincing, that are the adenovirus gene recombination and the altered viral tropism induced by cofactors. Particularly, a superantigen theory is more appealing, i．e. gastrointestinal adenovirus infection induces an onset of SARS-CoV-2 superantigen-mediated toxic shock and hepatocellular apoptosis. However, the true etiology still needs to be determined. This review intends to update available information regarding epidemiological investigation, etiological analysis, pathological alteration, laboratory examination, pathogenic detection, guidelines of diagnosis and treatment, as well as quarantine and preventive measures of SAHUEC, and to provide contemporary understanding of the underlying mechanisms for better therapy.