Initial manifestations and clinical course of systemic onset juvenile idiopathic arthritis: a ten-year retrospective study.

BACKGROUND/PURPOSE: The diagnosis of systemic onset juvenile idiopathic arthritis (SoJIA) on disease onset is challenging and made mainly by exclusion. This study aimed to investigate the initial clinical and laboratory features of children with SoJIA in Taiwan.

METHODS

Patients diagnosed with SoJIA at the National Taiwan University Hospital between 1997 and 2007 were evaluated and data were collected by retrospective chart review. Inferential statistics were used to compare features of patients with steroid use for <6 months or >6 months.

RESULTS

Twenty-eight (28) patients (13 boys and 15 girls) were included in this study. The mean age of onset was 8.7 years old. The most common presentations were fever (100%), arthritis (89.3%), and skin rash (67.9%). The patterns of arthritis in affected patients were 50% oligoarticular type and 39% polyarticular type. The most common joints involved were the knee (76% of patients with arthritis), ankle (56%), and elbow and proximal interphalangeal joints (28%). The most common pattern of fever during first week was intermittent (53%). Prolonged use of steroid was associated with leukocytosis (17.63±7.71 vs. 11.93±4.43×10(9) leukocytes/L, p<0.05) and higher aspartate aminotransferase (89.4 vs. 31.2 U/L, p<0.05) on initial presentation.

CONCLUSION

In SoJIA, extra-articular features such as fever, rash, and lymphadenopathy are most prominent. Leukocytosis and polyarticular pattern on presentation may indicate a refractory clinical course.