Positive family history of psoriasis does not affect the clinical expression and course of juvenile idiopathic arthritis patients with oligoarthritis

Objective. In the 1997 revision of the International League of Associations for Rheumatology (ILAR) criteria for juvenile idiopathic arthritis (JIA), a family history of psoriasis is an exclusion for the oligoarthritis category. We investigated whether psoriasis in a first or second degree relative influences the clinical expression and course of JIA patients with oligoarthritis. Methods. In a cross-sectional study, consecutive oligoarticular-onset JIA patients were investigated. Clinical evaluations included confirmation of a family history of psoriasis and assessment of nail abnormalities, dactylitis, psoriatic rash, variables of JIA activity, and laboratory indicators of inflammation. Retrospective assessments included sex, onset age, disease duration, antinuclear antibodies, HLA-B27, uveitis, ocular complications, second-line therapies, intraarticular corticosteroid injections, radiographic joint lesions, joint involvement over time, and laboratory investigations at disease presentation and first observation. Results. A total of 185 patients were included. Thirty-three had a positive family history of psoriasis (group 2) and 139 did not (group 1). Thirteen patients fulfilled the ILAR criteria for juvenile psoriatic arthritis (group 3). Patients in groups 1 and 2 were comparable for all parameters, except for a higher frequency of females in group 1 (P = 0.04). As compared with group 2, patients in group 3 were less frequently antinuclear antibody positive and had a more severe arthritis and a different distribution of joint involvement. Conclusion. We found close similarities in the clinical features and course among patients with oligoarthritis who had a positive family history for psoriasis and those who did not. These findings argue against the exclusion of the former patients from the oligoarthritis category of JIA.