TY - JOUR T1 - Isolated axial disease in psoriatic arthritis and ankylosing spondylitis with psoriasis JF - Annals of the Rheumatic Diseases JO - Ann Rheum Dis SP - 1678 LP - 1684 DO - 10.1136/ard-2022-222537 VL - 81 IS - 12 AU - Timothy S H Kwok AU - Mitchell Sutton AU - Daniel Pereira AU - Richard J Cook AU - Vinod Chandran AU - Nigil Haroon AU - Robert D Inman AU - Dafna D Gladman Y1 - 2022/12/01 UR - http://ard.bmj.com/content/81/12/1678.abstract N2 - Objectives To compare isolated axial psoriatic arthritis (PsA), axial PsA with peripheral involvement and isolated axial ankylosing spondylitis (AS) with psoriasis. To evaluate predictors for developing peripheral disease from isolated axial PsA over time.Methods Two PsA and AS cohorts identified patients with PsA with axial disease and isolated axial patients with AS with psoriasis. Logistic regression compared isolated axial PsA to axial PsA with peripheral involvement and isolated axial AS with psoriasis. Cox proportional hazards model evaluated predictors for developing peripheral disease from isolated axial PsA.Results Of 1576 patients with PsA, 2.03% had isolated axial disease and 29.38% had axial and peripheral disease. human leucocyte antigen HLA-B*27 positivity (OR 25.00, 95% CI 3.03 to 206.11) and lower Health Assessment Questionnaire scores (OR 0.004, 95% CI 0.00 to 0.28) were associated with isolated axial disease. HLA-B*27 also predicted peripheral disease development over time (HR 7.54, 95% CI 1.79 to 31.77). Of 1688 patients with AS, 4.86% had isolated axial disease with psoriasis. Isolated axial patients with PsA were older at diagnosis (OR 1.06, 95% CI 1.01 to 1.13), more likely to have nail lesions (OR 12.37, 95% CI 2.22 to 69.07) and less likely to have inflammatory back pain (OR 0.12, 95% CI 0.02 to 0.61) compared with patients with isolated axial AS with psoriasis.Conclusions Isolated axial PsA and AS with psoriasis are uncommon. HLA-B*27 positivity is associated with isolated axial PsA and may identify those who develop peripheral disease over time. Isolated axial PsA is associated with better functional status. Isolated axial PsA appears clinically distinct from isolated axial AS with psoriasis.Data are available upon reasonable request. Data may be made available from the senior author upon request. ER -