Macrophage activation syndrome (MAS) is a potentially fatal complication of a number of rheumatological conditions, but few studies assessed it in juvenile dermatomyositis (JDM). Indeed, MAS is not considered as a frequent complication of JDM, but its occurrence could be under-estimated. In order to address this issue, we performed a revision of the available medical literature, describing and assessing patients with both MAS and JDM. After retrieving 253 records initially, 11 papers were selected as appropriate for our research objective, which provided a total of 12 patients affected with both MAS and JDM. Our pooled case series suggested that MAS in JDM may not be very rare, even though no final conclusion about its incidence and mortality rate can be made. However, JDM-related MAS seems to be difficult to treat, since methylprednisolone pulse therapy alone was not sufficient in most cases. Moreover, MAS in JDM patients often occurred at the onset of the rheumatic disease, before the final diagnosis of JDM could be established. Finally, MAS criteria validated for systemic Juvenile Idiopathic Arthritis (sJIA) resulted to be a very useful guidance to diagnose MAS in JDM patients as well, but their reliability may not be absolute. Therefore, cohort and multicenter studies are needed to assess the incidence and improve the diagnostic criteria for MAS in JDM patients.

中文翻译：

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少年皮肌炎巨噬细胞活化综合征：系统评价。

巨噬细胞活化综合症（MAS）是许多风湿病的潜在致命并发症，但很少有研究在青少年皮肌炎（JDM）中对其进行评估。实际上，MAS不被认为是JDM的常见并发症，但是其发生率可能被低估了。为了解决这个问题，我们对现有的医学文献进行了修订，描述和评估了MAS和JDM患者。最初检索253条记录后，选择了11篇适合我们研究目的的论文，总共为12名同时受到MAS和JDM影响的患者。我们汇总的病例系列表明，即使无法就其发病率和死亡率得出最终结论，JDM中的MAS也不是很罕见。但是，与JDM相关的MAS似乎很难治疗，因为仅在大多数情况下单独使用甲基泼尼松龙脉冲疗法是不够的。此外，JDM患者的MAS常常在风湿性疾病发作之前发生，无法确定JDM的最终诊断。最后，针对系统性幼年特发性关节炎（sJIA）进行验证的MAS标准也可作为诊断JDM患者MAS的非常有用的指南，但其可靠性可能不是绝对的。因此，需要进行队列研究和多中心研究来评估JDM患者中MAS的发生率并改善其诊断标准。验证了针对系统性幼年特发性关节炎（sJIA）的MAS标准也是诊断JDM患者MAS的非常有用的指导，但其可靠性可能不是绝对的。因此，需要进行队列研究和多中心研究来评估JDM患者中MAS的发生率并改善其诊断标准。验证了针对系统性幼年特发性关节炎（sJIA）的MAS标准也是诊断JDM患者MAS的非常有用的指导，但其可靠性可能不是绝对的。因此，需要进行队列研究和多中心研究来评估JDM患者中MAS的发生率并改善其诊断标准。