Axial spondyloarthritis is classified as a seronegative spondyloarthropathy. The seronegative spondyloarthropathies (including psoriatic arthritis, enteropathic arthritis, and reactive arthritis) are a heterogenous group of conditions with overlapping clinical manifestations and association with the gene HLA-B27.
Axial spondyloarthritis is a chronic progressive inflammatory arthropathy, which ultimately may lead to radiographical changes in the spine and sacroiliac joints. This radiographical stage is known as ankylosing spondylitis (AS).
Inflammatory back pain is the hallmark clinical feature. This is defined as back pain that is of insidious onset, is worse in the morning, and improves with exercise.
A positive response to non-steroidal anti-inflammatory drugs (NSAIDs) is characteristic of most patients.
Physiotherapy and NSAIDs are the cornerstone of treatment. In people whose symptoms are refractory to these approaches, tumour necrosis factor-alpha inhibitors and interleukin-17 inhibitors play a key role.
Axial spondyloarthritis (axSpA) is a chronic progressive inflammatory arthropathy. Patients present with severe pain and spinal stiffness, which ultimately may lead to radiographical changes in the spine and sacroiliac joints. This radiographical stage is known as ankylosing spondylitis (AS). Progression of disease may lead to spinal fusion. Patients with complete spinal fusion suffer extreme disability.
AS mainly affects the axial skeleton, although peripheral joints, entheses (tendon or ligament attachments to bone), and extra-articular sites such as the eye and bowel are frequently affected.
Non-radiographical axial spondyloarthritis (nr-axSpA) describes axial inflammation visible on magnetic resonance imaging (MRI) that has not caused substantial erosive damage to the sacroiliac joints. Patients can be classified as nr-axSpA on the basis of a positive MRI of the sacroiliac joint.
History and exam
Key diagnostic factors
- presence of risk factors
- inflammatory back pain
- presentation in late teens and early 20s
- male sex
- positive family history of AS
Other diagnostic factors
- sleep disturbance
- tenderness at sacroiliac joint
- loss of lumbar lordosis
- peripheral joint involvement
- symptoms of inflammatory bowel disease
- endoplasmic reticulum aminopeptidase 1 (ERAP1) and interleukin-23 receptor (IL23R) genes
- positive family history of AS
- male sex
- Klebsiella pneumoniae
1st investigations to order
- pelvic x-ray
Investigations to consider
- cervical spine x-ray (lateral)
- lumbar spine x-ray (lateral)
- thoracic spine x-ray (lateral)
adults with pain and/or stiffness
adults without pain and/or stiffness
adults with pain and/or stiffness refractory to 2 NSAIDs and non-pharmacological measures
Antoni Chan, MBChB, FRCP, PhD
Royal Berkshire NHS Foundation Trust
AC has served on the advisory boards for MSD, Novartis, and Sanofi; contributed to educational events for Janssen, MSD, Novartis, Sanofi, and Celgene; been on the speaker bureau for Janssen, Pfizer, and Novartis; and received travel grants from AbbVie, UCB, Lilly, and Pfizer to attend educational conferences.
Sarah Sacks, MBBS, BSc
Specialist Registrar in Rheumatology
Stoke Mandeville Hospital
SS declares that she has no competing interests.
Dr Antoni Chan and Dr Sarah Sacks would like to gratefully acknowledge Dr Jessica Gunn, Dr Sarah Keidel, Dr Millicent Stone, Dr Raj Sengupta, Dr Athimalaipet V. Ramanan, and Dr Emma Pomeroy, the previous contributors to this topic.
JG, SK, RS, and AVR declare that they have no competing interests. MS is an author of several references cited in this topic. EP is an author of a reference cited in this topic.
Roger Sturrock, MD, FRCP
Professor of Rheumatology
Centre for Rheumatic Diseases
University Department of Medicine
Glasgow Royal Infirmary University Trust
RS is an author of a reference cited in this topic.
Andrew Keat, MBBS
Consultant Physician and Rheumatologist
Northwick Park Hospital
AK declares that he has no competing interests.
Karl Gaffney, BCh, BAO (Hons), FRCPI, FRCP
Norfolk and Norwich University Hospital
Norwich and the Cromer & District Hospital
KG is an author of a reference cited in this topic.
Alexios G. Carayannopoulos, DO, MPH
Interventional Spine Physiatrist
Pain Medicine Specialist
AGC declares that he has no competing interests.
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