New recommendations developed to unify sJIA and AOSD

sJIA and AOSD share the same features, and the same four major symptoms. However, the two conditions have traditionally been separated by a person's age at diagnosis. Until now, before the age of 16, a patient would be diagnosed with sJIA, and after 16 they would be diagnosed with AOSD. Critically, this has translated into different treatment options. Several drugs have been approved in sJIA in recent years, but not in AOSD - mainly due to the rarity of the adult-onset form, which has made it difficult to run trials. This has meant that effective, advanced therapies have been accessible only for people whose disease started before the age of 16 years. People with AOSD, whilst experiencing the same disease, have been left behind.

To address this, EULAR has worked with PReS to develop new recommendations to unify these two diseases and give advice on diagnosis and management. The work was completed by a task force of researchers, healthcare professionals, and patient representative. The group completed a literature review to collect up-to-date evidence. The new work, published in the September month 2024 issue of the Annals of the Rheumatic Diseases, includes 14 individual recommendations, and 4 important overarching principles.

Crucially, the first of the overarching principles stresses that EULAR and PReS see sJIA and AOSD as the same disease and recommend that from now on they be called by the same name: Still's disease instead of sJIA or AOSD.

The principles go on to say that treatment targets and the strategy for looking after people with Still's disease should be based on shared decision making between the patient (and their parents or caregivers for young patients) and the treating team. Treat-to-target is a strategy used in other rheumatological conditions, and this should also be practised in Still's disease - with the ultimate goal of achieving drug-free remission. Finally, there is a risk of risk of macrophage activation syndrome (MAS) in people with Still's disease, and this should be detected promptly and treated rapidly.

Of the 14 recommendations, 3 are around diagnosis, 2 focus on timing and targets, 3 are on treatment choices, and the remaining 6 look at specific complications of Still's disease.

These are the first consensus for the diagnosis and management of children and adults with Still's disease. EULAR hope the new recommendations will help to unify two previously separate diseases, and help to improve outcomes for all patients, no matter what age they are when they receive their diagnosis.