Psoriatic arthritis is chronic inflammatory condition affecting multiple tissues including skin and joints. Axial psoriatic arthritis (axPsA) forms part of the SpA spectrum, may occur in the form of spondylitis with or without sacroiliitis. Spondylitis presents clinically with spinal stiffness and pain, while sacroiliitis causes alternating buttock pain. Although different classification criteria have been used for axPsA, a clear distinction is still not available. Spondylitis occurs in 40% of patients with PsA and may result in fusion of the vertebrae. These manifestations may be present on radiological examination without symptoms or signs. Some patients had silent axial disease, thus it was suggested that in order to identify axPsA, recognition of which has prognostic value, rheumatologists should consider conducting axial imaging for all patients with PsA regardless the presence of back pain.

Aim of the work:
To study spinal involvement in patients with psoriatic arthritis clinically and radiographically.

Patients and Methods
Patients:
Fifty patients diagnosed with PsA according to the classification criteria for psoriatic arthritis (CASPAR) were enrolled. Patients were classified into three groups based on the absence or presence of spinal involvement clinically and/or radiographically:
Group (Ι): patients with peripheral PsA (pPsA) only.
Group (ΙI): PsA patients with radiographic axial involvement (AxPsA-R)
Group (ΙII): PsA patients with clinical and radiographic axial involvement (AxPsA-CR).
Patients with orthopedic diseases or other rheumatic disorders affecting the spine and psychiatric and neurological disorders were excluded.