Refers to all forms of arthritis that begin before the age of 16 years, and persists for more than 6 weeks and are of unknown cause.
Most common chronic rheumatic disease in children.
Prevalence in developed countries between 16 and 150 per 100,000.
Subtype-systemic arthritis-affects males and females equally, accompanied by quotidian fever of at least 2 weeks duration, and may have a non-fixed erythematous rash hepatosplenomegaly, generalized lymphadenopathy or serositis.
Subtype-systemic arthritis-during fever peaks may be associated with abdominal pain or myalgias.
Subtype-systemic arthritis-arthritis is often symmetrical, polyarticular and may develop later in the course of the illness.
Subtype-systemic arthritis-lab abnormalities include anemia, leucocytosis, elevation in the ESR and CRP concentration and thrombocytosis.
Subtype-systemic arthritis-anemia associated with IL-6 induced iron sequestration in the reticuloendothelial system.