Table 1.
Clinical characteristics in a Nordic cohort of children with juvenile idiopathic arthritis, classified according to the ILAR classification criteriab and followed for at least seven years
| Clinical characteristics | ||||||||
|---|---|---|---|---|---|---|---|---|
| Number of patients n | Age at onset median (IQR) | Psoriasis n | Psoriasis- like rash n | Dactylitis n | Nail pitting n | Patients assessed for heredity n | First-degree heredity for psoriasis or psoriatic arthritis n (%) | |
| Systemic arthritis | 18 | 4.5 (2.2-6.7) | - | - | - | - | 18 | - |
| Oligoarticular persistent | 133 | 5.1 (2.6-8.5) | - | 1 | 6 | 3 | 123 | - |
| Oligoarticular extended | 78 | 4.1 (1.8-8.4) | - | 2 | 1 | 3 | 74 | - |
| Polyarticular RF negative | 80 | 4.9 (2.2-9.1) | - | 2 | 7 | - | 79 | - |
| Polyarticular RF positive | 3 | 10.2, 13.2, 13.3 | - | - | - | - | 3 | - |
| Psoriatic arthritis | 14 | 5.8 (4.3-7.9) | 8 | 3 | 3 | 7 | 14 | 9 (64.3) |
| Enthesitis-related arthritis | 49 | 10.0 (6.8-12.3) | - | 3 | 1 | 2 | 47 | - |
| Undifferentiated arthritis | 65 | 7.8 (3.2-11.8) | 6a | 2 | 6 | 3 | 57 | 51 (78.5) |
aNone of the six patients with psoriasis at the 8-year follow-up fit any category, four because of mutual exclusion from JPsA and ERA because of enthesitis, one because he was a HLA-B27-positive boy older than 6 years at onset, one because of positive RF
bInternational League of Associations for Rheumatology classification criteria [10] assessed at last study visit (median 98, range 84–147 months)