Does systemic-onset juvenile idiopathic arthritis belong under juvenile idiopathic arthritis?

'Science is the systematic classification of experience' George Henry Lewes (1817-78), English philosopher, critic, dramatist, scientist. Juvenile idiopathic arthritis (JIA) is prevalent in about 1 in 1000 children. The earliest formal description of this disease was by Sir George Frederick Still in 1897. This work was done when he was a registrar at the Hospital for Sick Children, Great Ormond Street, London. In this initial description of 19 patients he identified three patterns of arthritis, one of which came to be known later as Still's disease [now known as systemic-onset juvenile idiopathic arthritis (SoJIA)]. Over the next few decades it came to be appreciated that one form of arthritis in children is very different and dominated by the presence of systemic manifestations. Over the last two decades several paediatric rheumatologists have come together to classify juvenile arthritis for purposes of better disease identification and research. All along, the systemic form of juvenile arthritis was always recognized as belonging to a distinct group; in fact for several decades (and even now in some countries) the systemic form of juvenile arthritis was referred to as Still's disease. In this article we will attempt to highlight the reasons why we feel that SoJIA is perhaps not best retained in the company of JIA.