Successful Management of Still's Disease with Severe Liver Injury Through the administration of Baricitinib：A Case Report

Dabin Tang^1,2Jiang Yubao^1,2Yanying Zhang^1,2Jingjing Xie^1,2*Jian Yong Zhang^1,2*

• ¹The Fourth Clinical Medical College, Guangzhou University of Chinese Medicine, Shenzhen, China
• ²The Department of Rheumatology, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China

Still's disease (SD) is a rare systemic autoinflammatory disorder of unknown etiology, clinically characterized by a triad of high-spiking fevers, an evanescent salmon-colored rash, and arthritis. The disease exhibits considerable heterogeneity, ranging from mild manifestations to severe, life-threatening complications such as macrophage activation syndrome (MAS). Management strategies are tailored according to disease severity, with glucocorticoids remaining the mainstay of treatment for moderate to severe cases. However, a subset of patients becomes glucocorticoid-dependent or refractory, necessitating the use of steroid-sparing immunosuppressive agents. Recent advancements in biologic therapies have significantly improved disease outcomes and are increasingly adopted as first-line therapies. The Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway, known to be activated in various autoimmune and inflammatory conditions, has emerged as a promising therapeutic target. Herein, we present a case of SD complicated by severe liver injury, which was successfully managed with baricitinib following the failure of conventional synthetic disease-modifying antirheumatic drugs.