Demographic and clinical features at onset in 132 patients with systemic juvenile idiopathic arthritis. Data are median (interquartile range) unless indicated otherwise.
| Characteristic | Early Onset | Late Onset | p |
|---|---|---|---|
| Age at disease onset, mo | 12 (11–16) | 60 (36–96) | 0.00001 |
| Sex female, n (%) | 14 (74) | 64 (57) | NS |
| Delay in diagnosis, mo | 2 (1–3) | 2 (0–3) | NS |
| No. active joints (%) | 13 (3.5–20) | 8.5 (3–20) | NS |
| Polyarthritis, n (%) | 12 (63) | 80 (71) | NS |
| Rash, n (%) | 16 (84) | 78 (69) | NS |
| Lymphadenopathy, n (%) | 8 (42) | 55 (49) | NS |
| Splenomegaly, n (%) | 8 (42) | 33 (29) | NS |
| Hepatomegaly, n (%) | 9 (47) | 31 (27) | 0.05 |
| Serositis, n (%) | 6 (32) | 14 (12) | 0.01 |
| White blood cell count, × 109/l | 21.1 (17.6–26.2) | 18.4 (13.9–23.6) | NS |
| Hemoglobin, g/l | 82.5 (6.7–10.3) | 96 (8.6–10.4) | 0.03 |
| Platelets, × 109/l | 707 (414–876) | 530 (401–735) | 0.03 |
| Erythrocyte sedimentation rate, mm/h | 105 (73–117) | 105 (87–120) | NS |
NS: nonsignificant.