Juvenile Idiopathic Arthritis

Juvenile idiopathic arthritis (JIA) comprises a group of heterogenous disorders characterized by childhood-onset chronic joint inflammation. It is the most common rheumatologic disease in the pediatric population and an important cause of chronic illness in children. Early recognition and treatment are vital to prevent sequelae of uncontrolled inflammation on the developing skeleton. JIA can have significant complications that general pediatricians should be aware of, especially uveitis, which can be insidious and asymptomatic in very young children, and macrophage activation syndrome, which can be life-threatening if not recognized and appropriately treated. Although advances have been made in the past few decades, the etiology of JIA remains incompletely understood. Efforts are underway to refine the classification of JIA. The currently accepted classification scheme identifies subsets of JIA that are important clinically in terms of prognosis and tailoring treatment approaches. However, it is limited in identifying homogenous groups of children with early childhood onset and antinuclear antibody positivity, which may have different pathogenic mechanisms that could be important in developing more targeted and effective treatment approaches in the future. Treatment strategies for JIA have changed significantly in recent years with the availability of multiple newer targeted therapies, often modeled after medications used in adult-onset forms of arthritis. These treatments, and likely many others to come, have markedly improved symptom control and reduced complications in patients with JIA.