Inflammatory back pain criteria perform well in subset of patients with active axial psoriatic arthritis but not among patients with established axial disease

How Are We Addressing Axial Psoriatic Arthritis in Clinical Practice?

Psoriatic arthritis (PsA) is a chronic inflammatory disease affecting the musculoskeletal system, skin and nails. In addition to peripheral joints, inflammation of the spine and sacroiliac joints may occur. Yet, research into this axial phenotype has lagged behind partly because of the challenge in its clinical identification with a lack of specific clinical, molecular or imaging biomarkers. In the absence of a validated definition of what constitutes axial PsA (axPsA), guidelines for the management of axial involvement in PsA in clinical practice are scarce. On the basis of a literature review and their clinical expertise, a group of rheumatology experts provide their opinion to aid the diagnosis and management of axial PsA in clinical practice.

Proposal of a new diagnostic algorithm for adult-onset Still's disease

OBJECTIVE

This study was performed to develop a new diagnostic algorithm for adult-onset Still's disease (AOSD).

METHODS

We conducted a multicenter prospective nationwide case-control study in tertiary Internal Medicine, Rheumatology, and Infectious Diseases departments, to include successively patients with suspected AOSD based on the presence of two or more major criteria of Yamaguchi and/or Fautrel classifications. Patients were classified as AOSD or controls according to a predefined procedure. A receiving operating characteristic curve was used to determine the best cutoff value of the points-based score for disease classification. A diagnostic algorithm was developed to help the physician in the diagnostic approach.

RESULTS

A total of 160 patients were included, 80 patients with AOSD and 60 controls with different diagnoses. Twenty patients with incomplete data were excluded. In the multivariate analysis, 6 items remained independently associated with AOSD diagnosis: typical rash (OR: 24.01, 3 points), fever ≥ 39 °C (OR: 17.34, 3 points), pharyngitis (OR: 10.23, 2 points), arthritis (OR: 9.01, 2 points), NLR ≥ 4 (OR: 11.10, 2 points), and glycosylated ferritin ≤ 20% (OR: 1.59, 1 point). AOSD should be considered if the patient satisfies 7 points with a sensitivity of 92.5%, specificity of 93.3%, and accuracy of 92.8% (area under the curve (AUC): 0.97 [95% CI: 0.94-0.99]). The present points-based score was more accurate and sensitive than the Yamaguchi classification (78.8%, 92.5%, p = 0.01) and Fautrel classification (76.3%, 92.5%, p = 0.004). A typical rash associated with a points-based score ≥ 7 points leads to a very likely disease.

CONCLUSION

The proposed new algorithm could be a good diagnostic tool for adult-onset Still's disease in clinical practice and research. Key Points • A diagnostic algorithm was performed to help the physician in the diagnostic approach of AOSD. • The points-based score included in this algorithm had a high sensitivity and accuracy. • This diagnostic algorithm can be useful in the clinical research.

Axial involvement in psoriatic arthritis

Among the variety of clinical manifestations of psoriatic arthritis (PsA) – including peripheral arthritis, dactylitis, enthesitis, and axial disease – spondylitis is the least studied. There is no generally accepted definition of axial PsA (axPsA), nor is there any common terminology or diagnostic criteria for it. In the rheumatology community, there is also no consensus regarding radiological and MRI assessment of axial involvement in PsA patients, while disease activity indexes and the therapeutic tactics are borrowed from those used in treating axial spondyloarthritis (axSpA) and ankylosing spondylitis (AS). However, despite a range of similarities in immunopathogenetic mechanisms of axPsA and axSpA, there are also certain differences that may affect the treatment response in these patients. The aim of this review is the analysis of data on axial disease in PsA. The article discusses the genetic features, clinical presentations, imaging techniques, differential diagnostics and treatment options of axPsA.

Axial involvement in psoriatic arthritis: An update for rheumatologists

Psoriatic arthritis (PsA) is a heterogenous, chronic, inflammatory musculoskeletal disease that can lead to peripheral and axial damage and loss of function. Axial involvement occurs in 25% to 70% of patients with PsA, varying greatly depending on its definition, with the key manifestations being sacroiliitis and/or spondylitis. However, there are no agreed-upon classification or diagnostic criteria for axial involvement in PsA and no consensus on treatment paradigms, which complicates management of PsA. There have only been a few studies assessing biologics in patients with PsA with axial involvement, and most treatment plans are based on evidence from patients with axial spondyloarthritis. Rheumatologists therefore face many challenges in the management of axial PsA, including diagnosis, differential diagnosis, and choice of appropriate treatment. In this review, we summarize the clinical presentation, imaging characteristics, differential diagnoses, treatment options, and prognosis of axial PsA, with the aim of increasing rheumatologists' knowledge of this phenotype of PsA and thereby aiding its optimal management.

Axial Psoriatic Arthritis

PURPOSE OF REVIEW

To review current understanding of the prevalence, clinical features, outcome measures and recent therapeutic trials in axial psoriatic arthritis (axPsA).

RECENT FINDINGS

The prevalence of axPsA is estimated at 40-50%. However, the definition of axPsA remains unclear, therefore these estimates may be inaccurate. Ax PsA appears to be distinct from ankylosing spondylitis in demographic, clinical, genetic and therapeutic features. Because of the lack of widely accepted definition of axPsA it has been difficult to design therapeutic trials for this domain of PsA. Several studies have demonstrated the uniquness of axPsA. Few recent trials suggest that therapies that work for peripheral arthritis also work for axPsA.

Evaluating Inflammatory Versus Mechanical Back Pain in Individuals with Psoriatic Arthritis: A Review of the Literature

Psoriatic arthritis (PsA) is a chronic immune-mediated disease characterized by psoriatic skin and nail changes, peripheral joint inflammation, enthesitis, dactylitis, and/or axial involvement, either alone or in combination with each other. The presence of axial involvement has been shown to be a marker of PsA severity; however, there is no widely accepted definition of axial involvement in PsA (axPsA) or consensus on how or when to screen and treat patients with suspected axPsA. Chronic back pain is a prominent feature of axPsA and is thought to have a relevant role in early identification of disease. Chronic back pain can be caused by inflammatory back pain (IBP) or mechanical back pain (MBP). However, MBP can complicate recognition of IBP and delay diagnosis of axPsA. While MBP can also be associated with chronic back pain of ≥ 3 months in duration that is typical of IBP, IBP is characterized by inflammation of the sacroiliac joint and lower spine that is differentiated from MBP by key characteristic features, including insidious onset at age < 40 years, improvement with exercise but not with rest, and nighttime pain. This review discusses the differences in identification and management of IBP and MBP in patients with PsA with axPsA. The summary of available evidence highlights the importance of appropriate and timely screening, difficulties and limitations of differential diagnoses and treatment, and unmet needs in axPsA.

Axial Psoriatic Arthritis: A Distinct Clinical Entity in Search of a Definition

Axial involvement in psoriatic arthritis is a well-recognized manifestation with a prevalence between 12.5% and 78%. This huge heterogeneity is due to the different criteria used by authors to define psoriatic arthritis with axial involvement combining clinical features with radiographic evidence of disease. Specific genetic and clinical attributes of axial psoriatic arthritis might differentiate it from axial spondyloarthritis with concurrent skin psoriasis. Few studies address the specific management. The purpose of this review is to acknowledge the current understanding of axial involvement in psoriatic arthritis and highlight the need for a definition to facilitate research and clinical recognition.

Challenges in the clinical diagnosis of psoriatic arthritis

Psoriatic arthritis (PsA) is a chronic heterogeneous inflammatory musculoskeletal disease. The non-specific and often subtle manifestations make early diagnosis and subsequent treatment challenging. In the absence of diagnostic criteria and biomarkers, the diagnosis is often delayed leading to poor long-term outcomes. In addition, the differential diagnosis of a patient presenting with arthritis in the setting of skin psoriasis is wide due to symptom overlap with many other diseases. Peripheral arthritis, dactylitis, enthesitis and axial arthritis are the 4 domains of musculoskeletal involvement in PsA and careful examination of each domain by a rheumatologist is the first step for a correct diagnosis. Other extra-musculoskeletal features such as the presence of uveitis, inflammatory bowel disease, nail psoriasis and elevated acute phase reactants aid in the diagnosis of PsA. Screening patients with skin psoriasis using validated questionnaires might help in early diagnosis especially when coupled with imaging.