Background: Psoriatic arthritis (PsA) affects up to one- third of people with psoriasis (PsO) over the entire course of the disease. There are no sufficient biomarkers to predict the transition to PsA in patients with PsO. Recently, a ~10% probability of developing PsA within the initial 12 months of follow-up, increasing to 22.7% after 36 months, was identified in PsO patients with subclinical PsA and symptoms of arthralgia, with oligoarthritis arthritis being the predominant presentation pattern and musculoskeletal symptoms persisting for an extended period [1]. Moreover, a EULAR task force developed points to consider for the definition of clinical and imaging features suspicious for progression from PsO to PsA, proposing a nomenclature reflecting a temporal, although non-linear continuum, of psoriatic disease, with a stage (a) of PsO patients ‘at higher risk’ (eg, severe skin involvement, nail involvement), (b) a ‘subclinical stage’, including clinical features, namely arthralgia and/or imaging features typically linked to more imminent progression to PsA and (c) a ’clinical’ stage, defined by the presence of clinical synovitis in an individual with PsO [2].

Objectives: This study was set up to examine the prevalence of PsA-specific findings in patients with psoriasis but no musculoskeletal (MSK) complains about musculoskeletal symptoms (stage (a) according to the EULAR points to consider).

Methods: This was a multi-center prospective study with a total of 154 psoriasis patients in Germany. Patients with already established diagnosis of psoriasis were consecutively recruited from dermatology practices if they had no musculoskeletal symptoms reported so far. Exclusion criteria were newly diagnosed PsA (diagnosis up to the clinical at the rheumatologist), age <18 years and previous or current b- or ts-DMARD or corticosteroid treatment. After agreement, patients were referred to a specialized university rheumatology center within 4 weeks, who performed a clinical and laboratory examination, power doppler ultrasound (PDUS) of both hands and both heels and referred the patient to MRI examination of the dominant hand, the thoracic and lumbar spine and the SIJ.

Results: A total of 154 patients were included, 57.8% were male, mean age 46.8±12.8 years, PsO diagnosis duration 16.9±13.7 years, median BSA for PsO 7,5%, nail involvement was found in 56.9%. Overall, 22 patients (14.4%) were receiving csDMARDs. The mean CRP was 0.2mg/dl, 7.2% were HLA-B27 positive, the mean overall pain level (NRS 0-10) was 4.6±3.0. In the rheumatological clinical examination, tender joints count was 6.5±9.2, while swollen joints count was 0.3±1.1. There was no active dactylitis found, while 12% self-reported a history of dactylitis. The GEPARD questionnaire was positive in 82.2% and the mean DAPSA score was 16.4±13.5. In the imaging examinations, PDUS positive inflammatory signal was found in the hands of 3.9% patients, while enthesitis of the Achilles’ tendon or the plantar fascia was found in 7.8% patients. Furthermore, using MRI, inflammatory findings were found in 8.2% patients in the hand, in 1.0% patients in the thoracic spine, in 1.0% patients in the lumbar spine and in 2.5% in the SIJ MRI examinations. A clinical diagnosis of PsA was made after the completion of all examinations in 14.3% and a suspicion of PsA was present in 5.9% patients, while only 14.9% of both these groups fulfilled the CASPAR classification criteria. Patients with clinical signs of PsA had significantly more frequently PDUS positive for enthesitis or MRI positive for inflammatory lesions as compared to those without.

Conclusion: A substantial amount (1 out of 5) patients with long-standing psoriasis were found to have high suspicion or also a diagnosis of PsA, even without clinical complains of arthritis, after extensive clinical and imaging evaluation. Especially the combination of PsO with history of dactylitis or with joint tenderness should prompt physicians to initiate more dedicated examinations, especially imaging, in order to identify silent inflammatory lesions which may lead to early PsA diagnosis, before the full disease picture becomes clinically evident.

REFERENCES: [1] Zabotti A et al, RMD Open 2024.

[2] Zabotti A et al, Ann Rheum Dis 2024.

Acknowledgements: NIL.

Disclosure of Interests: Philipp Sewerin AXIOM Health, AMGEN, AbbVie, Astra Zeneca, Biogen, Bristol-Myers Squibb,Boehringer Ingelheim, Celgene, Celltrion, Chugai Pharma Marketing Ltd., Deutscher Psoriasis-Bund, Fresenius Kabi, Gilead Sciences, Galapagos Pharma, Hexal Pharma, Janssen-Cilag, Johnson & Johnson, Lilly, medi-login, Medac, Mediri GmbH, Novartis Pharma, Onkowissen GmbH, Pfizer, Roche Pharma, Rheumazentrum Rhein-Ruhr, Sanofi-Genzyme, Swedish Orphan Biovitrum, UCB Pharma, AXIOM Health, AMGEN, AbbVie, Astra Zeneca, Biogen, Bristol-Myers Squibb,Boehringer Ingelheim, Celgene, Celltrion, Chugai Pharma Marketing Ltd., Deutscher Psoriasis-Bund, Fresenius Kabi, Gilead Sciences, Galapagos Pharma, Hexal Pharma, Janssen-Cilag, Johnson & Johnson, Lilly, medi-login, Medac, Mediri GmbH, Novartis Pharma, Onkowissen GmbH, Pfizer, Roche Pharma, Rheumazentrum Rhein-Ruhr, Sanofi-Genzyme, Swedish Orphan Biovitrum, UCB Pharma, AbbVie, Novartis, Janssen, Cellgen, Panagiotis Ermeidis: None declared, David Kiefer AbbVie, Eli Lilly, Galapagos, Janssen, Novartis and UCB, AbbVie, Eli Lilly, Galapagos, Janssen and UCB, Novartis, Ioana Andreica Astra Zeneca, Chugai, Gilead, UCB, Abbvie, Alfasigma, Amgen, Astra Zeneca, Chugai, Galapagos, GSK, Janssen, Lilly, MSD, Novartis, Pfizer, Springer, Sobi,Takeda, UCB, Abbvie, Alfasigma, Amgen, Gilead, Lilly, Novartis, Pfizer, Sobi, Takeda, UCB, Lilly, Uta Kiltz AbbVie, Amgen, Eli Lilly, Fresenius, GSK, Hexal, J&J, MSD, Novartis, UCB, AbbVie, Amgen, Eli Lilly, Fresenius, GSK, Hexal, J&J, Novartis, UCB, AbbVie, Amgen, Fresenius, GSK, Hexal, Novartis, Falk Bechara AbbVie Inc., AbbVie Deutschland GmbH & Co. KG, Acelyrin, Beiersdorf, Boehringer Ingelheim Pharma GmbH & Co. KG, Celltrion, Dr. Wolff, Incyte Corporation, JanssenCilag GmbH, Johnson & Johnson, Merck, Mölnlycke, MoonLake, Novartis Pharma GmbH, Sanofi, Sitala and UCB Pharma, AbbVie Inc., AbbVie Deutschland GmbH & Co. KG, Acelyrin, Beiersdorf, Boehringer Ingelheim Pharma GmbH & Co. KG, Celltrion, Dr. Wolff, Incyte Corporation, JanssenCilag GmbH, Johnson & Johnson,Merck, Mölnlycke, MoonLake, Novartis Pharma GmbH, Sanofi, Sitala and UCB Pharma, AbbVie, MoonLake, Boehringer Ingelheim Novartis Pharma, UCB Pharma, Janssen Cilag GmbH, Dr. Wolff, Lennart Ocker: None declared, Matthias Hoffmann: None declared, Xenofon Baraliakos Abbvie, Alphasigma, Amgen, BMS, Cesas, Celltrion, Galapagos, Janssen, Lilly, Moonlake, Novartis, Pfizer, Roche, Sandoz, Springer, Stada, Takeda, UCB, Zuellig, Abbvie, Alphasigma, Amgen, BMS, Cesas, Celltrion, Galapagos, Janssen, Lilly, Moonlake, Novartis, Pfizer, Roche, Sandoz, Springer, Stada, Takeda, UCB, Zuel, Abbvie, Alphasigma, Amgen, BMS, Cesas, Celltrion, Galapagos, Janssen, Lilly, Moonlake, Novartis, Pfizer, Roche, Sandoz, Springer, Stada, Takeda, UCB, Zuel.

© The Authors 2025. This abstract is an open access article published in Annals of Rheumatic Diseases under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ). Neither EULAR nor the publisher make any representation as to the accuracy of the content. The authors are solely responsible for the content in their abstract including accuracy of the facts, statements, results, conclusion, citing resources etc.