Chronic arthritis in childhood is a group of diseases that vary in their mode of origin, course and course, and presumably in their etiology. At present, we refer to these diseases as juvenile idiopathic arthritis (JIA), which is defined as unexplained joint swelling lasting more than 6 weeks in children under 16 years of age, except for other diseases. Juvenile idiopathic arthritis has different manifestations and is usually divided into the following types: 1. Systemic juvenile idiopathic arthritis: one or more arthritic joints with concurrent or preceding fever for at least 2 weeks, including daily chills for at least 3 consecutive days, accompanied by one or more of the following symptoms: transient, non-fixed erythematous rash; generalized lymph node enlargement; hepatosplenomegaly; plasmacytitis, etc. 2. oligoarticular juvenile idiopathic arthritis: 1-4 joints are involved in the first 6 months of disease onset, with two subtypes: (1) persistent oligoarticular JIA: the number of joints involved is less than or equal to 4 throughout the course of the disease; (2) extended articular JIA: the number of joints involved is greater than or equal to 5 after 6 months of disease. (3) (rheumatoid factor negative) polyarticular juvenile idiopathic arthritis: the initial 6 months of disease onset, more than 5 joints involved, rheumatoid factor negative. 4, (rheumatoid factor positive) polyarticular juvenile idiopathic arthritis: the onset of the first 6 months, more than 5 joints involved, and in the first 6 months with a minimum interval of more than 3 months and more than 2 times rheumatoid factor positive. 5. Psoriatic juvenile idiopathic arthritis: 1 or more arthritis combined with psoriasis, or arthritis combined with at least 2 of the following: finger (toe) inflammation; nail depression or nail detachment; family history of first-degree relatives with psoriasis, etc. 6. Juvenile idiopathic arthritis associated with adhesion point inflammation: arthritis combined with adhesion point inflammation, or arthritis or adhesion point inflammation with at least 2 of the following: (1) current presentation or history of sacroiliac joint compression and or inflammatory lumbosacral pain; (2) HLA-B27 positive; (3) male children over 6 years of age with onset of disease; (4) acute or symptomatic anterior uveitis; (5) Family history of first-degree relatives with ankylosing spondylitis, arthritis associated with inflammation of attachment sites, such as inflammatory bowel disease arthritis, Reiter’s syndrome, acute anterior uveitis, etc. 7) Uncategorized juvenile idiopathic arthritis: arthritis that does not fit any of the above or fits more than two of the above categories.