What is Juvenile chronic arthritis, systemic-onset?

Juvenile chronic arthritis, systemic-onset: A form of joint disease in children whose systemic signs and symptoms include high intermittent fever, a salmon-colored skin rash, swollen lymph glands, enlargement of the liver and spleen, inflammation of the lungs (pleuritis), and inflammation around the heart ( pericarditis). The arthritis itself may not be immediately apparent, but in time it surfaces and may persist after the systemic symptoms are long gone. Also known as systemic-onset chronic arthritis or Still's disease.