Systemic Juvenile Idiopathic Arthritis.

Systemic juvenile idiopathic arthritis (sJIA) is a distinctive subtype of juvenile idiopathic arthritis, characterized by fever and arthritis, often accompanied by rash, sometimes by generalized lymphadenopathy, hepatosplenomegaly, and serositis. The diagnosis requires adequate exclusion of infectious, oncologic, autoimmune, and autoinflammatory diseases. Macrophage activation syndrome, a serious and potentially fatal complication of sJIA, requires prompt evaluation and treatment. Newer biologic agents, particularly interleukin-1 and interleukin-6 inhibitors, are highly effective and have transformed the treatment approach by reducing the use of systemic glucocorticoids. Primary care providers have a crucial role in monitoring children with sJIA for disease-related complications and medication-related adverse events.