Recently, some patients have asked me several times about the concept of adult Still’s disease, and I am giving you a more detailed introduction. Adult Still’s disease is a systemic rheumatic disease with three major clinical manifestations: fever, rash, and arthralgia/inflammation, often with mononuclear-phagocytic system involvement (e.g., pharyngitis, lymph nodes, hepatosplenomegaly), and with laboratory features (increased white blood cells and serum ferritin) that should be prominent when acute. From 1897, when it was first reported by pathologist George F. Still, to 1971, when Eric Bywaters officially named the disease, the disease is still poorly understood, the pathogenesis is still unclear, and the diagnosis is still exclusionary, mainly by empirical treatment. Diagnostic criteria: mainly refer to Cush et al. criteria and Japanese criteria, Fautrel et al. proposed a new classification criteria in 2002, listing fever ≥ 39°C, arthralgia, pharyngitis, transient rash, neutrophil ≥ 80%, and glycosylated ferritin ≤ 20% as the main criteria; leukocytes ≥ 10×109/L and fixed maculopapular rash as secondary criteria. It is considered that ≥4 major criteria, or 3 major criteria + 2 minor criteria are sufficient to diagnose the disease, and no other diseases need to be excluded.