Classification, diagnosis, and referral of patients with axial spondyloarthritis.

The concepts for classification, diagnosis and referral of patients with axial spondyloarthitis differ, although they of course basically relate to the same disease. While classification criteria and referral strategies concentrate largely on patients with chronic back pain with an age at onset before 45 years, the rheumatologist can make a diagnosis of axial SpA in patients with late onset or in patients with back pain for only some weeks if other items are fulfilled. Early recognition of patients with axial SpA is important to establish the diagnosis, potentially start therapeutic interventions and avoid unnecessary health care procedures.