Abstract
The term Juvenile Idiopathic Arthritis (JIA) denotes a group of childhood diseases characterised by the presence of chronic arthritis and variable degree of extra-articular manifestations according to the disease subtype. In the disease aetiology, exposure to environmental factors such as microbial antigens triggering inadequate immune response in a genetically pre-disposed host has been suggested.
Diagnosis of JIA is purely clinical, laboratory investigations assist differential diagnosis, disease classification and standardised outcome assessment. Systemic JIA (sJIA) with constitutional symptoms and often rapidly progressive destructive polyarthritis is the most serious disease subtype.
Macrophage activation syndrome is a life-threatening complication of sJIA. The most common JIA subtype, oligoarthritis, bears a high risk of chronic uveitis, mainly in its early-onset type affecting children below 6 years of age.
Timely diagnosis and appropriate disease management are the main prognostic factors. Long-acting intra-articular corticosteroids and methotrexate belong to the most common treatments.
Therapeutic failure or drug intolerance lead to an introduction of biologics with TNFalpha blockers being most commonly used in resistant polyarthritis. Inhibition of interleukin 6 and 1 has found its place mainly in the treatment of sJIA.