Systemic onset juvenile idiopathic arthritis (SJIA) is an uncommon condition with several features suggestive of an autoinflammatory disease.
Features of systemic onset juvenile idiopathic arthritis:
(1) age at onset < 16 years
(2) >= 3 consecutive days of quotidian fever
(3) arthritis in >=1 joint
(4) one or more of the following: evanescent erythematous rash, generalized lymphadenopathy, hepatomegaly, splenomegaly or serositis
Complications:
(1) macrophage activation syndrome (MAS)
(2) interstitial lung disease (ILD)
(3) amyloidosis
Criteria for refractory SJIA - one or both of the following:
(1) failure to respond to IL-1 and/or IL-6 inhibitors
(2) need for ongoing treatment with long-term (> 6 months) glucocorticoids with persistence of systemic and/or arthritic features
