Distribution (percentages) of selected features by category in 235 Indian children with juvenile idiopathic arthritis, classified by the ILAR classification system (Edmonton, 2001).
| Features/Subset | Systemic Arthritis, n = 19 | OLA-P, n = 39 | OLA-E, n = 10 | Polyarthritis, RF−, n = 41 | Polyarthritis RF+, n = 28 | Psoriatic Arthritis, n = 3 | Enthesitis-related Arthritis, n = 84 | UnA, n = 11 | All Patients, n = 235 |
|---|---|---|---|---|---|---|---|---|---|
| Median onset age, yrs | 5.25 | 10 | 9.75 | 11.5 | 13 | 12 | 13 | 11 | 12 |
| Range for onset age, yrs | 1.5–13 | 1–16 | 1–14 | 1–15.5 | 2–16 | 5–12 | 7–16 | 2–15.5 | 1–16 |
| Female | 42.1 | 59 | 70 | 61 | 88.9 | 66.7 | 9.5 | 45.5 | 41.7 |
| Cervical spine | 16.7 | 2.5 | 20 | 14.6 | 11.1 | 0 | 7.2 | 13.3 | 9.8 |
| Thoracic spine | 0 | 0 | 0 | 2.4 | 0 | 0 | 6 | 0 | 2.6 |
| Lumbar spine | 5.5 | 7.7 | 0 | 7.3 | 14.8 | 0 | 33.7 | 20 | 17.4 |
| Sacroiliac joint | 0 | 0 | 0 | 4.9 | 0 | 0 | 19 | 18.1 | 8.5 |
| Enthesitis | 5.2 | 0 | 0 | 0 | 3.6 | 0 | 36.9 | 27.2 | 15.3 |
| Eye | 5.2 | 2.6 | 0 | 0 | 0 | 0 | 8.3 | 0 | 3.8 |
| Liver/spleen | 26.3 | 0 | 0 | 0 | 0 | 0 | 0 | 9.1 | 2.6 |
| RF-positive | 0 | 0 | 0 | 0 | 100 | 0 | 0 | 82 | 15.7 |
| ANA (positive/no. tested) | 11.8 (2/17) | 8 (2/25) | 10 (1/10) | 16.7 (5/30) | 27.3 (6/22) | 0 (0/2) | 7.4 (5/68) | 20 (2/10) | 12.5 (23/184) |
| HLA-B27 (positive/no. tested) | 0 (0/8) | 16.7 (3/18) | 0 (0/6) | 15.8 (3/19) | 15.8 (3/19) | 100 (1/1) | 88.7 (55/62) | 40 (4/10) | 48.3 (69/143) |
UnA: undifferentiated arthritis; RF: rheumatoid factor; ANA: antinuclear antibody; ILAR: International League of Associations for Rheumatology.