Understanding Axial Spondyloarthritis: A Hidden Cause of Chronic Back Pain

What is Axial Spondyloarthritis?

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease that primarily affects the spine and sacroiliac joints (the joints connecting the lower spine to the pelvis). Unlike typical mechanical back pain, axSpA is driven by immune system dysfunction and inflammation, which can lead to stiffness, chronic pain, and even spinal fusion in severe cases.

The condition often starts in early adulthood, typically before age 45, and affects both men and women. Because the symptoms mimic common back pain, many patients experience years of delay before receiving an accurate diagnosis.

Types of Axial Spondyloarthritis

AxSpA is broadly divided into two categories:

• Non-radiographic axSpA (nr-axSpA): Inflammation is present, but structural damage is not visible on X-rays. Diagnosis often relies on MRI findings and clinical features.

• Ankylosing Spondylitis (AS): A more advanced form where X-rays show clear evidence of sacroiliac joint damage. Over time, new bone formation may lead to spinal fusion, reducing flexibility and mobility.

  
  

Signs and Symptoms

People with axSpA may experience:

• Chronic back pain lasting more than three months

• Pain that improves with exercise but not with rest

• Morning stiffness lasting 30 minutes or more

• Alternating buttock pain

• Fatigue and reduced mobility

• Extra-articular symptoms such as uveitis (eye inflammation), psoriasis, or inflammatory bowel disease

Because symptoms overlap with other conditions, axSpA is often underdiagnosed or mistaken for mechanical back pain.

Causes and Risk Factors

The exact cause of axSpA remains unknown, but several factors play a role:

• Genetics: A strong link exists with the HLA-B27 gene.

• Immune dysregulation: The body’s immune system mistakenly triggers chronic inflammation.

• Environmental factors: Gut microbiome changes and infections may influence disease onset.

Not everyone with HLA-B27 develops axSpA, but those who do often present at a younger age and with more severe symptoms.

Diagnosis

Diagnosing axSpA requires a careful combination of:

• Medical history and symptom review

• Physical exam to assess spinal mobility and pain patterns

• Imaging tests such as MRI (to detect early inflammation) and X-ray (for structural damage)

• Blood tests for markers of inflammation (CRP, ESR) and genetic testing for HLA-B27

Early detection is essential to prevent irreversible joint damage.

Treatment and Management

There is no cure for axSpA, but effective therapies help control symptoms and prevent progression:

• Lifestyle measures: Regular exercise, posture training, and smoking cessation.

• Medications:

  • NSAIDs (first-line treatment for pain and inflammation)

  • Biologic therapies such as TNF inhibitors and IL-17 inhibitors

  • DMARDs (for associated arthritis outside the spine)

• Physical therapy: Improves mobility, posture, and lung capacity.

• Surgery: Rarely needed, but joint replacement or corrective spinal surgery may be considered in severe cases.

Living with Axial Spondyloarthritis

Managing axSpA is a long-term journey. Many patients benefit from a multidisciplinary approach involving rheumatologists, physical therapists, and patient support groups. With proper treatment, people with axSpA can maintain an active lifestyle and minimize disease impact.

Raising awareness is vital recognizing that chronic back pain in young adults may be more than “just a sore back” can shorten the diagnostic delay and improve outcomes.

References

1. Sieper J, Poddubnyy D. Axial spondyloarthritis. Lancet. 2017;390(10089):73–84.

2. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Axial Spondyloarthritis Information. Accessed September 2025.

3. Ward MM, Deodhar A, Gensler LS, et al. 2019 Update of the American College of Rheumatology/Spondylitis Association of America/Spondyloarthritis Research and Treatment Network Recommendations for the Treatment of Ankylosing Spondylitis and Non-radiographic Axial Spondyloarthritis. Arthritis Rheumatol. 2019;71(10):1599–1613

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