Abstract
The term juvenile idiopathic arthritis (JIA) describes a group of diseases manifesting themselves during the childhood with chronic arthritis and variable rate of extra-articular symptoms. The systemic-onset JIA (SJIA) is the rarest and the most serious form of this disease.
It is characterized by the presence of systemic symptoms and often by rapidly progressing destructive polyarthritis. Macrophage activation syndrome is a life threatening complication of SJIA.
Early diagnosis, and commencement of appropriate therapy are limiting factors in SJIA prognosis. Differential diagnosis may be challenging at the time of disease onset and include other inflammatory conditions as well as systemic malignancies.
Except for systemic glucocorticosteroids, the treatment consists in particular of biological agents blocking the proinflammatory cytokines interleukin 1, and 2. Their administration usually enables the corticotherapy to be stopped and thus prevents the development of serious adverse effects such as growth retardation, obesity, hypertension, and cataract, often seen before.
Relatively high relapse rate when attempting to stop the treatment remains an issue and number of paediatric patients carries various level of disease activity to their adulthood.