label: rheumatoid factor-negative juvenile idiopathic arthritis
label_lc: rheumatoid factor-negative juvenile idiopathic arthritis
description: "Rheumatoid factor-negative polyarthritis is a term used to describe a group of poorly defined heterogenous conditions that incorporates forms of rheumatoid factor-negative polyarthritis and forms of oligoarticular arthritis that become extensive in less than 6 months after onset."