Spondyloarthritis (SpA) is a group of chronic inflammatory diseases affecting the musculoskeletal system. These diseases are mediated by the immune system and share epidemiological, genetic, immunopathological, clinical, radiographic, and therapeutic response characteristics. This group includes axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA). AxSpA is characterised by involvement of the sacroiliac joints and the spine, as well as the sites where ligaments attach to bone (entheses), and it may also affect peripheral joints.1,2 PsA is a chronic inflammatory disease affecting the skin and musculoskeletal system. It usually affects the peripheral joints and around 30% of patients also have axial skeletal involvement. Enthesitis and dactylitis (inflammation of the tendon sheaths causing the finger to swell like a sausage) are also common. Both diseases can be associated with inflammation of the eyes (uveitis) and the intestines (Crohn's disease and ulcerative colitis).3,4

A clinical practice guideline (CPG) is a document presenting a set of recommendations based on a systematic review of the evidence and an assessment of the risks and benefits of different alternatives, with the goal of improving patient care.5 The recommendations of the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) for diagnosing and treating these rheumatic diseases are the most widely used internationally. In Spain, the ESPOGUIA guideline has been produced by the Spanish Society of Rheumatology (SER) since 20093 and updated twice, in 2015 and 2018.6,7

Given the time that has elapsed since the publication of the previous CPG,6 and the significant advances that have emerged in recent years, mainly in the area of therapeutic innovations and new treatment strategies, the SER decided on an update and the new “Guideline for the treatment of axial spondyloarthritis and psoriatic arthritis” was published in December 2024.8 The aim was to establish current recommendations, based on the best available evidence, aimed at improving the quality of care and quality of life of people with axSpA and PsA, and to assist rheumatology specialists in therapeutic decision-making in this group of diseases.

The 2024 CPG is the result of the work of a large group of healthcare professionals (drafting group [DG]) from different autonomous communities who are involved in managing patients with axSpA and PsA. This group includes specialists in rheumatology, dermatology, ophthalmology, gastroenterology, and nursing, as well as representatives of patient associations. Specialists in methodology, technicians from the SER Research Unit, and several rheumatologists from the SER working group of reviewers, as well as other external reviewers, were also involved in systematically reviewing the available scientific evidence. For the first time, ESPOGUÍA has incorporated the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology,9 both to determine the quality or certainty of the evidence and to grade the strength and direction of the recommendations.

The CPG incorporates new biological therapies for the treatment of PsA, including IL-23 and IL-17A/F inhibitors, as well as JAK1,3 and JAK1 inhibitors. It also includes new therapies for axSpA, such as IL-17A and IL-17A/F inhibitors, and new data on the efficacy and safety of IL-17A inhibition in axial PsA. Results from head-to-head studies comparing IL-17A and TNF-alpha inhibitors in PsA, as well as results from a clinical trial indicating that methotrexate could be an effective treatment for enthesitis and dactylitis in PsA (SEAM-PsA), have also been incorporated.10 Evidence from current retrospective studies suggesting that treating psoriasis, particularly with biological therapy, may prevent or delay the onset of PsA has also been included. Another new addition is an update on the debate as to whether axial spondyloarthritis and axial psoriatic arthritis are the same disease.

Several important topics are addressed in ESPOGUÍA 2024, including the disease burden of spondyloarthritis in Spain and the importance of patient empowerment in decision-making regarding their diagnosis and treatment. Thanks to patient involvement, systems have been developed to assess the impact of the disease on patients with PsA, such as PsAID. This allows us to identify which of the 12 physical, psychological, and sociological variables that make up their disease are having the greatest impact on their quality of life. These and other measures are also useful for improving treatment adherence. This is why the opinions of patients and nursing professionals are included in ESPOGUÍA.

The SER's ESPOGUÍA 2024 presents some key differences when compared to the EULAR recommendations for axSpA and also for PsA, since the ESPOGUÍA is a document that extensively develops aspects related to epidemiology and disease burden, the importance of dietary habits, toxin avoidance (e.g. tobacco and alcohol), and physical activity. These topics are not usually included in the EULAR11,12 or ACR recommendations.13,14 The final recommendations on disease management and treatment are essentially similar in ESPOGUÍA and EULAR, although the methodologies used to develop them are different: GRADE9 and OXFORD,15 respectively. The GRADE methodology explicitly structures the process of formulating recommendations. Among its novelties and strengths, it is worth highlighting that it evaluates the quality or certainty of the evidence for each outcome of interest; outcomes that have been previously prioritised by the DG; that the quality assessment goes far beyond the usual risk of bias, extending to factors such as the consistency or inconsistency of results or their imprecision. It also explicitly separates the quality of the evidence (confidence in the estimation of an effect to support a recommendation) from the strength of the recommendations (the extent to which we can trust that implementing a recommendation will result in more benefits than risks). Other relevant factors incorporated into the development of recommendations include patient values and preferences, the balance between the desirable and undesirable effects of interventions, and aspects such as equity, acceptability, feasibility of implementation, and resource use and costs. After summarising the evidence for each clinical question, the DG proceeded to formulate specific recommendations based on a “formal assessment” or “reasoned judgement”.

One of the most notable aspects is that ESPOGUÍA 2024 issues new recommendations for changing treatment following failure or intolerance to TNF-alpha inhibitors in axSpA and PsA. These recommendations depend on the extra-musculoskeletal manifestations of the disease, such as psoriasis, uveitis, or inflammatory bowel disease, as well as the patient's comorbidities (cardiovascular risk and obesity, etc.). The recommendation on reducing or withdrawing treatment for patients in remission has also been updated.

One of the most important conclusions of drafting ESPOGUÍA 2024, albeit a predictable one, is that new studies are needed to provide sufficient evidence to enable more robust recommendations to be made regarding prognostic factors and biomarkers of response to different targeted therapies, as well as studies comparing axSpA with axPsA. The future of treatment lies in personalised medicine, meaning providing patients with the right treatment for their disease and its status. However, achieving this goal is extremely challenging given that spondyloarthritis, including PsA, is a disease with many clinical phenotypes affecting various tissues (e.g., entheses, synovium, bone, and skin), with significant heterogeneity in response to treatment. These and other unmet needs are included in the ESPOGUÍA 2024 research agenda.

In summary, the ESPOGUÍA 2024 guideline for the treatment of axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA) was developed using a rigorous, evidence-based methodology. They aim to promote effective, safe, and coordinated decision-making among healthcare professionals regarding therapeutic interventions for axSpA and PsA, with a focus on the patients that suffer from them.