Axial spondyloarthritis is an inflammatory condition that primarily affects the spine and sacroiliac joints, causing pain and stiffness that develop gradually over time. It encompasses a spectrum of disease, ranging from early, non-radiographic forms through to ankylosing spondylitis, in which long-standing inflammation leads to new bone formation and, in more advanced cases, fusion of the spine.
The condition is often mistaken for ordinary mechanical back pain in its early stages, as symptoms develop slowly and can be difficult to distinguish from more common causes of back discomfort. This frequently leads to a significant delay between the onset of symptoms and a confirmed diagnosis.
Without appropriate assessment and management, axial spondyloarthritis can lead to progressive spinal stiffness, structural damage, chronic pain and a marked reduction in mobility and quality of life.
What is axial spondyloarthritis?
Axial spondyloarthritis is a chronic inflammatory arthritis that primarily affects the axial skeleton, including the spine and sacroiliac joints. It belongs to a wider family of conditions known as the spondyloarthropathies and is strongly associated with the HLA-B27 gene.
Inflammation in axial spondyloarthritis develops at the entheses, the sites where ligaments and tendons attach to bone. Over time, in ankylosing spondylitis, this ongoing inflammation can stimulate new bone formation, causing the small joints and discs of the spine to gradually fuse together and lose flexibility.
Symptoms typically begin in the late teens, twenties or early thirties. The condition has historically been considered more common in men and associated with more visible structural change on imaging, although it is increasingly recognised in women, who are often diagnosed later.
What are the symptoms of axial spondyloarthritis?
Symptoms of axial spondyloarthritis usually develop gradually and can closely resemble ordinary mechanical back pain, which means many people are not diagnosed until symptoms have been present for some time.
Signs and consequences of axial spondyloarthritis may include:
- Chronic lower back pain and stiffness lasting more than three months, typically worse in the morning or after rest and improving with movement
- Pain in the buttocks or sacroiliac joints, which may alternate from one side to the other
- Reduced flexibility and mobility of the spine over time
- Persistent fatigue
- Pain, swelling or tenderness in peripheral joints or at entheses, such as the Achilles tendon or heel
Because axial spondyloarthritis can be mistaken for common mechanical back pain, early identification in people with characteristic, persistent symptoms is particularly important.
When should you seek care for axial spondyloarthritis?
You should seek specialist assessment if you have chronic back pain lasting more than three months that began before the age of 45, morning stiffness that improves with exercise but not rest, or associated conditions such as psoriasis, inflammatory bowel disease or uveitis.
Early assessment allows treatment to begin before significant structural damage occurs, helping to preserve spinal mobility and reduce the risk of long-term disability.
What causes axial spondyloarthritis?
Axial spondyloarthritis develops as a result of a combination of genetic and immune-mediated factors that lead to chronic inflammation of the spine and sacroiliac joints. A number of features increase the likelihood of developing the condition:
- Male sex, although the condition is increasingly recognised in women
- Younger age, with onset typically before the age of 45
- A family history of axial spondyloarthritis, ankylosing spondylitis or related conditions
- Presence of the HLA-B27 gene
- Associated inflammatory bowel disease, psoriasis or psoriatic arthritis
- Associated inflammatory bowel disease, including Crohn's disease or ulcerative colitis
- A history of uveitis or recurrent eye inflammation
- A preceding infection triggering reactive joint inflammation
- Smoking, which is associated with more severe symptoms and structural progression
- Other associated autoimmune or rheumatic conditions
How do we diagnose axial spondyloarthritis?
Diagnosis is based on a combination of clinical assessment, imaging and blood tests. There is no single test that confirms the condition on its own, particularly in its earlier, non-radiographic stages, and results need to be interpreted alongside your overall clinical picture.
Dr Nuttall will begin with a detailed review of your symptoms, medical history, family history and any associated conditions, together with a physical examination. Diagnostic tests may include:
- MRI of the sacroiliac joints and spine, which can detect early inflammation before changes are visible on a plain X-ray
- X-rays of the spine and sacroiliac joints, to identify structural changes such as fusion in more established disease
- Blood tests, including testing for the HLA-B27 gene and inflammatory markers such as CRP and ESR
- Physical examination assessing spinal mobility, posture and chest expansion
- Further imaging or specialist referral where peripheral joint or extra-articular features are present
Different patients require different investigations, and your diagnostic pathway will be tailored to your symptoms and clinical findings.
Axial spondyloarthritis treatment and management:
Treatment is aimed at reducing inflammation, controlling symptoms, preserving spinal mobility and preventing long-term structural damage. The approach is tailored to your individual disease activity, symptoms and overall health.
- Non-steroidal anti-inflammatory drugs (NSAIDs), usually the first-line treatment for pain and stiffness
- Physiotherapy and a structured, regular exercise programme to maintain spinal mobility and posture
- Biologic therapies, such as TNF inhibitors, for people with persistently active disease despite NSAIDs
- IL-17 inhibitors, an alternative biologic option for active disease
- JAK inhibitors, used in some cases where other treatments are unsuitable or ineffective
- Disease-modifying anti-rheumatic drugs (DMARDs), which may be used where there is peripheral joint involvement
- Peripheral joint steroid injections or systemic steroids for disease flares
- Lifestyle modifications, including smoking cessation, postural advice and staying physically active
- Regular specialist review to monitor disease activity and adjust treatment as needed
Dr Nuttall will tailor treatment to reduce inflammation, preserve spinal mobility, and support your long-term function and quality of life.
