Spondyloarthritis encompasses a group of inflammatory conditions with some shared features, including extra-articular manifestations. Both peripheral and axial joints can be affected. The spondyloarthritides are distinct from rheumatoid arthritis but are as important to recognise and manage early in their presentation to improve health outcomes.

Most people with these conditions have either psoriatic arthritis or axial spondyloarthritis, which includes ankylosing spondylitis. Ankylosing spondylitis and non-radiographic axial spondyloarthritis primarily affect the spine, in particular the sacroiliac joint. Both conditions present in similar ways; the primary classification difference is whether sacroiliitis is detectable on X‑ray.

Psoriatic arthritis may manifest in a number of different patterns. These include predominant involvement of small joints in the hands and feet, predominant large joint involvement, particularly in the knees, or combinations of these. Psoriatic arthritis may also involve the axial joints, and inflammation of the entheses and/or finger and toe joints. Skin and nail involvement may not be present at diagnosis and in its absence, a family history of psoriasis is required to meet the diagnostic criteria.

Less common subgroups are enteropathic spondyloarthritis, which is associated with inflammatory bowel disease (Crohn's disease and ulcerative colitis), and reactive arthritis, which can occur in people after gastrointestinal or genitourinary infections.

The final subgroup is people who have undifferentiated spondyloarthritis. These people generally have an asymmetrical oligoarticular (fewer than 5 involved joints) arthritis, often involving the knees. They do not meet the diagnostic criteria of the other subgroups at presentation but their disease may evolve to do so at a later stage.

This guideline also includes people who are 16 years or older with axial or peripheral symptoms who have previously been diagnosed with juvenile idiopathic arthritis.

Healthcare professionals in non-specialist settings do not always recognise the signs and symptoms of spondyloarthritis, particularly spinal symptoms, which may be mistakenly attributed to other causes of low back pain. This can lead to substantial delays in diagnosis and treatment with consequent disease progression and disability. This guideline seeks to raise awareness of the features of spondyloarthritis and provide clear advice on what action to take when people with signs and symptoms first present in healthcare settings.

This guideline also provides advice on the interventions available to people with spondyloarthritis. These include pharmacological and non-pharmacological treatments, and surgery. The guidance also provides advice on how care for people with spondyloarthritis should be organised across healthcare settings, and what information and support should be provided.