During the last decade, considerable changes in the treatment of psoriatic arthritis (PsA) have occurred, with clinical practice guidelines developed to assist physicians in integrating these changes into their practices, explains Alexis R. Ogdie-Beatty, MD, MSCE. In recent years, the American College of Rheumatology (ACR) and National Psoriasis Foundation (NPF) released their first joint treatment guideline, the European League Against Rheumatism (EULAR) updated its treatment guideline, and the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) developed a new guideline focused on PsA. To understand the differences in the three guidelines and assist physicians in deciding the correct treatment for patients in light of these differences, Dr. Ogdie-Beatty and colleagues reviewed and compared the recommendations.

For a paper published in Rheumatology (Oxford), Dr. Ogdie-Beatty and colleagues examined the development of the three recommendation sets and compared the differences and similarities between them. GRAPPA structured its recommendations based on disease domain and included a separate group to develop questions for patients with comorbidities. ACR/NPF developed their guideline through scoping meetings to decide which topics to address. EULAR used previous PsA recommendations to build its latest guideline.


A major difference with the ACR/NPF guideline compared with the EULAR and GRAPPA guideline relates to the therapies included and the terminology used in regard to oral therapies. The EULAR and GRAPPA guidelines continue to use previous terminology—conventional synthetic disease-modifying antirheumatic drugs (csDMARDs)— but make note of the limited evidence that supports the disease-modifying effects of these agents as it relates to structural damage. Comparatively, ACR/NPF renamed this category the oral small molecules (OSM). The ACR/NPF guideline also includes several therapies that did not have sufficient research and information available when the EULAR and GRAPPA guidelines were first developed.

All three guidelines structured their recommendations differently, most notably in order of therapy selection (Table). GRAPPA and EULAR both used “step-up” approaches. While both guidelines allow for skipping ahead through these steps the GRAPPA recommendations allow easier skipping based on disease severity, or presence of specific disease features, such as enthesitis. On the other hand, ACR/NPF offers specific recommendations for each situation, such as treatment-naïve active PsA and active PsA in the presence of enthesitis. ACR/NPF does not include a flow diagram in the guideline but instead provides specific figures for each scenario that show pairwise comparisons without providing an order of therapy selection or priority.

Disease Severity

The ACR guideline provides specific definitions of disease severity, whereas the EULAR and GRAPPA guidelines define disease severity based on poor prognostic factors, according to Dr. Ogdie-Beatty. Specifically, the EULAR recommendations suggest that patients with poor prognostic factors be treated more aggressively than patients with better prognostic factors, with poor prognostic factors including many swollen joints, structure damage in the presence of inflammation, high sedimentation rate or c-reactive protein, and clinically relevant extra-articular manifestations. Conversely, GRAPPA recommends accelerating treatment for patients with poor prognostic factors. “Considering the disease severity definitions can help when needing to know when to use a biologic therapy and in assisting patients with insurance coverage,” adds Dr. Ogdie-Beatty.

Looking Forward

“These guidelines are a great starting point for considering treatment decisions. However, since the recommendations are mostly based on applied evidence and not direct evidence, there is still research needed to fill in the gaps in PsA research,” notes Dr. Ogdie-Beatty. “Direct head-to-head comparisons of therapies including evidence for the line of therapy (ie, what therapies should be used first) are needed. Also, studies would be welcomed that provide a better understanding of how subpopulations or specific disease manifestations in this heterogeneous disease may respond differently to individual therapies.”