Key clinical point: Axial psoriatic arthritis (PsA) can be categorized as a distinct subtype of PsA because it exhibits clinical and radiological symptoms that are different from those of ankylosing spondylitis (AS) with psoriasis.
Major finding: Compared with patients with AS and psoriasis, patients with human leukocyte antigen (HLA)-B27-negative axial PsA had lesser inflammatory pain (P = .002), anterior uveitis (P = .014), and structural damage (P < .001) along with a higher prevalence of nail disease (P = .009) and were more likely to present with psoriasis before spondyloarthritis onset (P = .020). However, patients with HLA-B27-positive axial PsA vs AS and psoriasis reported lesser structural damage as revealed by Bath Ankylosing Spondylitis Radiology Index scores (P < .001).
Study details: This cross-sectional study included 109 patients with axial PsA and 127 patients with AS and current presentation or a history of skin psoriasis from the REGISPONSER registry.
Disclosures: The REGISPONSER registry is funded by the Spanish Society for Rheumatology. The authors declared no conflicts of interest.
Source: Michelena X et al. Characterising the axial phenotype of psoriatic arthritis: a study comparing axial psoriatic arthritis and ankylosing spondylitis with psoriasis from the REGISPONSER registry. RMD Open. 2022;8:e002513 (Dec 5). Doi: 10.1136/rmdopen-2022-002513