Axial psoriatic arthritis (axPsA) is a distinct but underdefined manifestation of psoriatic arthritis, primarily affecting the spine and sacroiliac joints. Despite its clinical relevance, there is no consensus definition or standardized classification for axPsA, complicating diagnosis and treatment. Experts emphasize the need for precise terminology—favoring “axial psoriatic arthritis” (axPsA)—and recommend active evaluation for axial symptoms in all patients with PsA. Diagnosis should involve a combination of detailed clinical assessment, genetic testing (especially HLA-B27 status), and imaging, such as spinal and pelvic radiographs or MRI when appropriate. Current classification systems like CASPAR and ASAS are not sufficiently sensitive or specific for axPsA, and efforts are ongoing to establish dedicated criteria.

Treatment for axPsA currently mirrors that of axial spondyloarthritis due to a lack of dedicated clinical guidelines. NSAIDs are considered first-line, followed by biologic or targeted synthetic DMARDs for those with inadequate response. Secukinumab, an IL-17A inhibitor, is the only therapy with demonstrated efficacy in a randomized controlled trial specifically for axPsA. Other treatment options, including TNF inhibitors and JAK inhibitors, show promise but lack axPsA-specific trial data. Given the potentially different pathophysiology and treatment responses compared with axSpA, more focused research is needed to define diagnostic criteria, monitoring tools, and optimized therapeutic strategies tailored to axPsA.

Reference: Michelena X, López-Medina C, De Miguel E, et al. How Are We Addressing Axial Psoriatic Arthritis in Clinical Practice? Rheumatol Ther. 2024 Dec;11(6):1441-1456. doi: 10.1007/s40744-024-00722-w. Epub 2024 Oct 18. PMID: 39422869; PMCID: PMC11557781.