The diagnostic criteria for rheumatoid arthritis in children are divided into five categories: 1) age of onset under 16 years old; 2) inflammation of one or more joints, manifested by joint swelling or fluid accumulation, which may be accompanied by joint movement limitation, joint pain, pressure pain, and increased local temperature of the joints; 3) duration of disease of more than 6 weeks; 4) within the first 6 months of onset, symptoms can be divided into three types, including polyarthritic type, which usually involves 5 or more joints; and oligoarthritic type, which involves 4 or fewer joints. The polyarthritic type, which usually involves 5 or more joints, and the oligoarthritic type, which involves 4 or fewer joints. The systemic type may have intermittent fever, rheumatoid rash, arthritis, enlarged liver, spleen and lymph nodes, and plasmacytosis.5 To exclude other types of disease, patients with rheumatoid arthritis in children can usually present with fever, rash, enlarged lymph nodes, and may also have internal organ damage such as liver, spleen, and heart damage. There are many types of arthritis, and many patients have significant joint effusion, but the joint lesions are mostly found in the large joints, and the symptoms of joint pain and morning stiffness are less severe than in adults, and functional impairment and deformity rarely occur. Therefore, the diagnosis of rheumatoid arthritis in children relies mainly on the symptoms of the condition.