Systemic juvenile idiopathic arthritis (sJIA), also known as systemic-onset JIA (SoJIA) is a rare auto-inflammatory disease, accounting for only 10% to 15% of children who have juvenile idiopathic arthritis (JIA). Though sJIA is considered to be a subtype of JIA, the symptoms, underlying cause and treatments for it are all different. Systemic JIA most commonly affects young children, but the symptoms may start at any age.
Systemic JIA used to be called “Still’s disease,” though most pediatric rheumatologists now refer to this condition as SJIA or SoJIA. The adult form of sJIA is still known as adult-onset Still's disease (AOSD), and this is also a very rare disorder.
Children with sJIA have fevers, rashes and arthritis. These symptoms may occur all at once or spread out over several days or weeks:
In children with sJIA, the innate immune system (the part of the immune system you are born with) is overactive. This leads to inflammation in the joints and in other parts of the body. The cause of this overactivity is not fully understood but is probably due to a combination of genetic and environmental factors.
There are no specific medical tests for sJIA. A doctor will typically make a diagnosis based on:
Your child’s rheumatologist may recommend an exam by an ophthalmologist to evaluate for ocular inflammation (uveitis), although this is less common than in the other types of JIA.
There is no cure for sJIA. The goal of treatment is to reduce the symptoms and treat the underlying inflammation. Many children require corticosteroids, as well as other immunosuppressive medications. Biologic medications that target specific inflammatory molecules (interleukins), such as anakinra, canakinumab and tocilizumab, may help treat both the systemic inflammation and the arthritis. These medications are given by injection or IV infusion.
Assistant Attending Physician, Hospital for Special Surgery
Assistant Professor of Pediatrics, Weill Cornell Medical College