Objective: To investigate the relationship between
psoriasis severity and clinical features in
psoriatic arthritis (PsA). Methods: Patients were recruited from the Chinese REgistry of
Psoriatic ARthritis (CREPAR) between December 2018 and June 2021, and data were collected including the baseline demographic characteristics, various clinical manifestations (including
arthritis,
nail disease, comorbidities), laboratory tests[including erythrocyte sedimentation rate(ESR),
C-reactive protein (CRP)], health assessment questionnaire (
HAQ). Body surface area (BSA) and
psoriasis area and severity index (PASI) were selected for the tools of assessment of cutaneous
psoriasis. Patients were divided to two groups, including the severe
psoriasis group (BSA>10%) and the non-severe
psoriasis group (BSA≤10%). Disease assessment included
ankylosing spondylitis disease activity score (ASDAS), disease activity score 28 (DAS28) and disease activity in
psoriatic arthritis (DAPSA). Results: 1 074 eligible patients with PsA were recruited, and 106 (9.9%) had severe
psoriasis. Compared with non-severe
psoriasis group, the severe
psoriasis group had more peripheral joint involvement (including patients with ever or current peripheral
arthritis, 94.3% vs. 85.6%), more polyarticular joint involvement (including patients with current peripheral
arthritis, 74.0% vs. 58.2%), more axial joint involvement (51.4% vs. 39.9%), more
nail disease (72.6% vs. 61.4%), more frequency of smoking (20.2% vs. 18.7%), and higher proportion of
hypertension (23.4% vs. 14.4%). In addition, the severe
psoriasis group had higher level of ESR [33(10, 70) mm/1h vs. 20(9, 38) mm/1h] and CRP [18.6(5.0, 60.8) mg/L vs. 7.0(2.4, 18.1) mg/L], higher values of DAS28-ESR (4.5±1.7 vs. 3.7±1.5), DAS28-CRP (4.2±1.5 vs. 3.4±1.4), ASDAS-ESR (3.5±1.4 vs. 2.6±1.2), and ASDAS-CRP(3.4±1.6 vs. 2.5±1.2), higher scores of
HAQ [0.6(0.1, 1.0) vs. 0.3(0.0, 0.8)]. Conclusion: Patients with PsA with severe
psoriasis bore a heavier disease burden. Therefore, clinicians were supposed to pay more attention to them. In addition to skin lesions, they should also focus on examination of other clinical manifestations, such as joints and nails.