Axial involvement is present in 25–70% of patients with psoriatic arthritis (PsA) and is an accepted marker of PsA disease severity.

Improved recognition of axial involvement may help to identify patients who are candidates for more aggressive and appropriate therapy that effectively treats the complete spectrum of PsA, including axial disease in PsA (axPsA).

Chronic back pain is also thought to have a relevant role in the early identification of axPsA and is usually accompanied by inflammatory back pain (IBP) symptoms but can be confused with mechanical back pain (MBP).

It is important to differentiate between IBP and MBP to ensure that patients with axPsA receive the most appropriate treatment.