[Association of skin lesion severity with clinical features of psoriatic arthritis]

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.