To study the incidence and prevalence of juvenile chronic arthritis (JCA) in northern Norway.
Cases from the period 1985-1994 were retrospectively identified from the hospital files of the only pediatric department treating JCA in the study area. The European League Against Rheumatism (EULAR) criteria for JCA were used.
The annual incidence of JCA was 22.6/100,000 children under 16 years of age. The incidence of oligoarticular JCA was 11.8, and the incidence of systemic JCA was 0.8/100,000. In the incidence group 25% were ANA positive, 14% developed uveitis and 42% of the tested patients were HLA-B27 positive. The point prevalence was 148.1/100,000.
These incidence and prevalence data are higher than those reported in most other studies. The impact of genetic differences, cyclic variations and other factors in relation to the onset and course of JCA merit further investigation.