TY - CHAP M1 - Book, Section TI - Systemic Arthritis A1 - Wells, Robert G. Y1 - 2015 N1 - T2 - Diagnostic Imaging of Infants and Children AB - Juvenile idiopathic arthritis (JIA; juvenile rheumatoid arthritis) encompasses a group of disorders that are clinically characterized by a chronic synovitis of unknown origin that begins when the patient is less than 16 years of age, and persists for more than 6 weeks. Subgroups of JIA include pauciarticular (4 or fewer joints involved), polyarticular (5 or more joints), and systemic-onset varieties. Synovial inflammation in these patients stimulates synovial proliferation and joint effusion. Pannus formation in the synovium can lead to erosion of cartilage and bone.1 SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/04/19 UR - accesspediatrics.mhmedical.com/content.aspx?aid=1148953394 ER -