Abstract
Systemic-onset juvenile idiopathic arthritis (SoJIA) is a form of juvenile idiopathic arthritis (JIA) that typically presents with prominent systemic features and accounts for approximately 10-15% of children with JIA. Pro-inflammatory cytokine pathways are thought to be involved in its pathogenesis, including interleukin-1 (IL-1) and interleukin-6 (IL-6), and laboratory tests demonstrate a prominent inflammatory response with high CRP and ferritin levels. We present a case of severe, aggressive, erosive SoJIA in a 17-year-old male resistant to multiple biologic therapies treated with a novel combination of IL-1 and IL-6 blockade along with subcutaneous methotrexate.