Musculoskeletal pain in psoriasis - relation to inflammation and additional value of ultrasound in psoriatic arthritis classification.
Rheumatology (Oxford) 2021;
61:2835-2847. [PMID:
34849603 DOI:
10.1093/rheumatology/keab865]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 11/14/2021] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVE
To investigate and compare clinical features and ultrasound signs of inflammation in joints and entheses in patients with psoriasis (PsO) with and without musculoskeletal pain, and the additional value of ultrasound in classification of psoriatic arthritis (PsA). Furthermore, to explore the association between such findings and patient-reported outcomes (PROs) and the performance of screening-questionnaires for identifying patients with PsA.
METHODS
Patients with PsO (n = 126) recruited from a nationwide survey were evaluated at one of four rheumatology departments. The evaluation included clinical examination, laboratory tests, radiography, greyscale (GS) and colour Doppler (CD) ultrasound of 48 joints and 12 entheses, PROs, and four screening-questionnaires for PsA. Patients were classified with Classification for PsA (CASPAR), ultrasound-modified CASPAR, and ultrasound-only criteria.
RESULTS
When subgroups of self-reported pain (63%), no pain (29%) and diagnosed PsA (9%) were compared, patients with pain had higher tenderness-related clinical scores (tender joints, entheses and fibromyalgia points) and ultrasound GS sum-scores, compared with 'no pain' patients. PROs were negligibly-moderately correlated with pain-related clinical scores (Spearman's rho = 0.11-0.59, all patients), and negligibly-weakly with ultrasound sum-scores (rho = 0.01-0.34). More patients could be classified as PsA when ultrasound synovitis/enthesitis was included as entry criterion (ultrasound-modified CASPAR, 66% of all patients) compared with conventional CASPAR (35%) or ultrasound-only criteria (52%). Sensitivities of screening-questionnaires were low for fulfilment of CASPAR (0.23-0.66), ultrasound-modified CASPAR (0.17-0.57), and ultrasound-only (0.20-0.57) criteria.
CONCLUSION
Self-reported pain in PsO is related to ultrasound inflammation. Ultrasound-modified CASPAR criteria identified almost twice as many patients as conventional CASPAR criteria. Screening-questionnaires showed limited value.
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