Juvenile Psoriatic Arthritis - Followup and Evaluation of Diagnostic Criteria

Abstract

<h4>Objective</h4>To describe the course of juvenile psoriatic arthritis (JPsA) defined by the "Vancouver Criteria."<h4>Methods</h4>A retrospective review of JPsA in 63 children, (44 girls, median age at onset 4.5 yrs; 19 boys, median age at onset 10.1 yrs) who fulfilled the Vancouver Criteria, as follows. Definite JPsA: arthritis with psoriasis, or arthritis with 3 of 4 minor criteria (nail pits, dactylitis, psoriasis-like rash, family history of psoriasis); probable JPsA: arthritis with 2 of the minor criteria.<h4>Results</h4>At last followup, 50 children had definite JPsA and 13 had probable JPsA. Rheumatoid factor was absent in all; antinuclear antibody was present in 50%. Thirty-eight children were followed for > 5 yrs, 18 for > 10 yrs, and 7 for > 15 yrs. Forty-four children had active arthritis; 32% were in functional class I, 38% in class II, 22% in class III, and 8% in class IV. Of the 46 patients with oligoarticular onset, 21 remained oligoarticular, and 25 became polyarticular. Arthritis in the small joints of the hands and feet increased in frequency, with arthritis eventually occurring in proximal interphalangeal joints in 63%, metacarpophalangeal or metatarsophalangeal joints in 55%, and distal interphalangeal joints in 27%. Dactylitis occurred in 35%, most commonly in 2nd toes and index fingers. Nine patients (14%) developed chronic anterior uveitis. Eleven of 24 patients (46%) who initially had probable JPsA evolved to definite JPsA after a median of 2.1 yrs. Five developed psoriasis and the remainder developed additional minor criteria. The 13 patients with a current diagnosis of probable JPsA did not differ significantly from the 50 patients with definite JPsA with respect to number of joints involved at onset or during the disease course. Patients with psoriasis (n = 41) did not differ from those with definite JPsA without psoriasis (n = 9) with respect to the number of joints involved at onset or during the disease course, functional class, or need for 2nd line therapy.<h4>Conclusion</h4>JPsA defined by the Vancouver Criteria is a relatively common chronic arthropathy of childhood that differs clinically, serologically, and genetically from both juvenile rheumatoid arthritis and juvenile ankylosing spondylitis.