JRA: Systemic, Pauciarticular, and Polyarticular Juvenile ArthritisWebMD explains juvenile rheumatoid arthritis (JRA) –- the types, signs and symptoms, how it's diagnosed, and the treatment.Polyarticular Juvenile Rheumatoid Arthritis - What is ...A form of juvenile rheumatoid arthritis which affects five or more joints.Juvenile idiopathic arthritis - Wikipedia, the free encyclopediaJuvenile idiopathic arthritis (JIA) (aka Juvenile Rheumatoid Arthritis JRA) is the most common form of persistent arthritis in children. (Juvenile in this context ...