Characteristics of patients with juvenile PsA and other subtypes of JIA. Values are numbers (%) of patients or mean ± standard deviation.
| PsA, n = 31 | Oligoarthritis, n = 137 | Polyarthritis, n = 68 | ERA, n = 55 | Undifferentiated Arthritis, n = 22 | Systemic Arthritis, n = 23 | |
|---|---|---|---|---|---|---|
| Male sex | 7 (23) | 29 (21) | 20 (35) | 36 (66)*** | 5 (23) | 10 (59) |
| Age at onset, range 1.7–15.2 yrs | 8.2 ± 3.6 | 6.0 ± 4.1** | 8.4 ± 4.2 | 11.1 ± 2.8*** | 6.9 ± 4.7 | 6.2 ± 4.4 |
| Age at followup visit, range 13.7–31.3 yrs | 23.3 ± 3.9 | 21.2 ± 4.6* | 23.1 ± 4.2 | 26.5 ± 3.0*** | 22.4 ± 5.2 | 20.7 ± 4.5* |
| Onset age > 6 yrs | 23 (74) | 62 (45)** | 35 (61) | 51 (93)* | 11 (50) | 11 (48) |
| Disease duration at followup visit, range 11.7–25.1 yrs | 15.0 ± 1.8 | 15.2 ± 2.3 | 14.7 ± 1.8 | 15.2 ± 2.3 | 15.5 ± 2.4 | 14.5 ± 1.3 |
| Disease duration at postal survey, range 16.1–31.7 yrs† | 22.9 ± 2.0 | 22.8 ± 2.2 | 22.4 ± 2.1 | 22.2 ± 2.5 | 22.6 ± 2.2 | 21.6 ± 1.8* |
| Oligoarticular arthritis at onset | 21 (68) | 137 (100)*** | 0*** | 40 (73) | 19 (86) | 16 (70) |
| Polyarticular course | 20 (65) | 42 (31)*** | 68 (100)*** | 37 (67) | 11 (50) | 13 (57) |
↵*** p < 0.001 versus PsA;
↵** p < 0.01 versus PsA;
↵* p < 0.05 versus PsA (not statistically significant when corrected for numbers of comparisons). PsA: psoriatic arthritis, ERA: enthesitis-related arthritis.
↵† n = 28 PsA, n = 110 oligoarthritis, n = 45 polyarthritis, n = 40 ERA, n = 18 undifferentiated arthritis, n = 17 systemic arthritis.