Joint Pain, Tenderness, and Limited Function May Signal Psoriatic Arthritis Onset

Among patients with psoriasis (PsO), arthralgia was associated with later development of psoriatic arthritis (PsA), as were joint pain, joint tenderness, and functional limitations, according to study results published in Rheumatic & Musculoskeletal Diseases Open.

Data on the phases preceding the transition from PsO or undifferentiated arthritis (UA) to PsA are limited. Investigators aimed to identify clinical characteristics of patients transitioning from PsO or UA to PsA, with the goal of establishing potential interventions for preventing or delaying PsA onset.

Using Medline, Embase, PubMed, and international congress abstracts, investigators conducted a systematic literature review of all articles listing features of patients progressing from PsO or UA to PsA. A meta-analysis was unable to be conducted, as data collected from included studies was too heterogeneous. Incidence rates (IRs) for development of PsA were calculated for all studies that included patients with PsO.

A total of 18 studies were included in the analysis.

The IRs for development of PsA among patients with PsO ranged from 1.6 to 24.4 per 100 patient-years among 9 studies.

Further analysis revealed that, among patients with with PsO, arthralgia was associated with later development of PsA, as were joint pain, joint tenderness, and functional limitations.

The finding of subclinical enthesopathy during imaging was also associated with an eventual diagnosis of PsA.

Peripheral arthritis, typically oligo-arthritis, was the most frequent finding at the onset of PsA, and the mean number of swollen joints ranged from 1.5 to 3.2. No target joints were found to predict the development of PsA or were typical of its onset.

Articular erosions apparent after conventional radiography were seen in 23% to 33% of patients with a new diagnosis of PsA.

Taken together, these findings led the study authors to conclude that very early PsA was mainly oligoarticular.

Results of this systematic review were used to inform the European League Against Rheumatism (EULAR) task force on the transition to PsA, defining the clinical and imaging features that may indicate PsO or UA progression to PsA.

This analysis was limited by the lack of a standard definition for PsA onset and its associated diagnostic criteria, significant risk for observer bias and selection bias, and lack of included studies with prospective or longitudinal designs. 

“In conclusion, the characterisation of the transitioning features from PsO to PsA is critical both on a scientific level, to improve our understanding of the pathobiology of PsA and on a pragmatic-clinical level, to improve our ability to prevent or intercept PsA development. This [systematic literature review] has served to bring together this preliminary information and has informed the guidance provided in the EULAR points to consider in this key area of transition to PsA,” the study authors stated.

Disclosure: One or more of the study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.