Study Reveals Challenges in Musculoskeletal Classification of Psoriasis, PsA

Results of an ongoing study published in Journal of Clinical Medicine demonstrated a notable prevalence of suspected musculoskeletal symptoms in patients with psoriasis (PsO); however, only a small portion could be directly attributed to psoriatic arthritis (PsA).¹

Alberto Floris, MD

Credit: University of Cagliari

“A close collaboration between dermatologists, who are the first ones to assess and follow up on PsO patients, and rheumatologists, who are responsible for the PsA diagnosis and its differentiation from other mimicking conditions, is strongly recommended,” wrote lead investigator Alberto Floris, MD, associated with the Department of Medical Sciences and Public Health, University of Cagliari, Italy, and colleagues. “However, clear evidence of the benefits of a systematic collaboration between the two specialists in managing PsO patients is still scarce, especially regarding the differential diagnosis.”

PsA is generally diagnosed in an overall clinical evaluation comprised of a physical examination, radiographic features, and a patient’s medical history. The clinical heterogeneity of the condition, lack of validated biomarkers, and delays in seeing a rheumatologist ultimately make a PsA diagnosis more challenging. If not diagnosed in a timely manner and adequately treated, PsA can result in reduced quality of life, joint damage, disability, and increased socioeconomic costs.²

To accurately diagnose PsA, a clinician must differentiate the condition from similar arthropathies and nonspecific arthralgia. To further complicate the diagnosis process, patients with PsO with musculoskeletal symptoms may not have PsA and instead are experiencing other arthropathies.³

The cross-sectional rheumatologic analysis of the ongoing DIAPASON (Early Diagnosis of PsA in a monocentric cohort of PsO patients) project analyzed 1057 adult patients with PsO to pinpoint specific challenges regarding the classification of musculoskeletal manifestations in this population.¹

The mean age at enrollment was 55.3 years, the mean PsO disease duration was 20.1 years, and 55.3% were male. Of the included patients, 209 (19.8%) were previously diagnosed with PsA. Out of the remaining 848 patients, 35% (n = 293) were categorized as suspected PsA according to a rheumatologist and/or had an Early PsA Screening Questionnaire (EARP) score of ≥3. Of those with suspected PsA, only 13.7% (n = 40) ultimately received a PsA diagnosis, while 48.3% (n = 142) had a PsA-alternative diagnosis, and 36.9% (n = 108) were classified as having nonspecific arthralgias.¹

Most patients with newly diagnosed PsA reported a symptom duration ≥1 year (72%) along with moderate disease activity (55%), active oligoarthritis (85%), dactylitis, or enthesitis (35%). The most common PsA-alternative diagnoses were osteoarthritis (44%) and fibromyalgia (41%). Factors deemed significant in discriminating PsA from other conditions and nonspecific arthralgias were young age as well as EARP score with a history of dactylitis, swollen joints, or morning stiffness.¹

While the results showed a high prevalence of suspected musculoskeletal symptoms in patients with PsO, only a small number were due to PsA.¹

Investigators noted the retrospective nature of the study as a limitation as it prevented an exact distinction between early and established PsA in newly diagnosed patients. Additionally, using data from a monocentric cohort from a tertiary dermatologic center may have hindered the generalization of results.¹

“Close collaboration between dermatologists and rheumatologists plays a crucial role not only in diagnosing and managing PsA but also in the distinction and management of other musculoskeletal disorders,” investigators concluded. “Follow-up data from these patients will provide further evidence regarding the benefits of the early recognition of the transition from PsO to PsA, especially in patients with nonspecific arthralgia, and an improvement in other long-term outcomes.”¹

References

1. ^{Floris A, Mugheddu C, Sichi L, et al. The Challenging Differentiation of Psoriatic Arthritis from Other Arthropathies and Nonspecific Arthralgias in Patients with Psoriasis: Results of a Cross-Sectional Rheumatologic Assessment of a Large Dermatologic Cohort. J Clin Med. 2023;12(18):6090. Published 2023 Sep 21. doi:10.3390/jcm12186090}
2. ^{Gratacós, J.; Behrens, F.; Coates, L.C.; Lubrano, E.; Thaçi, D.; Bundy, C.; de la Torre-Aboki, J.; Luelmo, J.; Voorneveld, H.; Richette, P. A 12-point recommendation framework to support advancement of the multidisciplinary care of psoriatic arthritis: A call to action. Jt. Bone Spine 2021, 88, 105175}
3. ^{Ritchlin, C.T.; Colbert, R.A.; Gladman, D.D. Psoriatic Arthritis. N. Engl. J. Med. 2017, 376, 957–970}