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In this section you can find out more information regarding Ankylosing Spondylitis (AS)

AS is a chronic inflammatory disease that primarily affects the spine while other areas of the body can be inflamed.

In more advanced cases, this inflammation can lead to ankylosis, causing sections of the spine to fuse in an immobile position.

AS tends to first develop in teenagers and young adults. Most cases first start in people aged 20-30, with only a minority of cases first affecting adults over 45.

AS is more common in men than in women.

There are around 200,000 people in the UK who have been diagnosed with AS.

What is Ankylosing Spondylitis (AS)?

References
1. NHS. Ankylosing spondylitis. Available at https://www.nhs.uk/conditions/ankylosing-spondylitis/ Accessed October 2022
2. Spondylitis Association of America (SAA). Ankylosing spondylitis diagnosis. Available at https://spondylitis.org/about-spondylitis/types-of-spondylitis/ankylosing-spondylitis/ Accessed October 2022
3. NHS Inform. Ankylosing spondylitis. Available at https://www.nhsinform.scot/illnesses-and-conditions/muscle-bone-and-joints/conditions/ankylosing-spondylitis Accessed October 2022

Causes

The exact cause of AS is not fully understood – but in many cases there is a link with a particular gene known as human leukocyte antigen B27 (HLA-B27). However, having this gene does not necessarily mean AS will develop. It's estimated 8 in every 100 people in the general population have the HLA-B27 gene, but most do not have AS.

Having the HLA-B27 may make people more vulnerable to developing AS. The condition may be triggered by 1 or more environmental factors, although it's not known what these are.

Risk Factors

Factors that may increase the risk of AS include:

Genetics

AS can run in families, and the HLA-B27 gene can be inherited from another family member.

Gender

Men are more likely to develop AS than women.

References
1. NHS. Ankylosing spondylitis - Causes. Available at https://www.nhs.uk/conditions/ankylosing-spondylitis/causes Accessed October 2022
2. Mayo Clinic. Ankylosing spondylitis. Available at https://www.mayoclinic.org/diseases-conditions/ankylosing-spondylitis/symptoms-causes/syc-20354808 Accessed October 2022

The main symptoms of AS are:

Pain and stiffness

  • In lower back and hips
  • Especially in the morning and after periods of inactivity
  • Gets better with exercise, but does not improve or gets worse with rest
  • Pain that causes sleep disturbance

Fatigue

  • Tiredness
  • Lack of energy

Arthritis

Inflammation of the joints (arthritis) in other parts of the body like the knees and hips.

Read more about Arthritis here.

Enthesitis

Painful inflammation where a bone is joined to a tendon (a tough cord of tissue that connects muscles to bones) or a ligament (a band of tissue that connects bones to bones).

What are the symptoms of AS? 1

What are the symptoms of AS? 2

References
1. NHS. Ankylosing spondylitis - Causes. Available at https://www.nhs.uk/conditions/ankylosing-spondylitis/causes Accessed October 2022
2. Mayo Clinic. Ankylosing spondylitis. Available at https://www.mayoclinic.org/diseases-conditions/ankylosing-spondylitis/symptoms-causes/syc-20354808 Accessed October 2022

AS can be difficult to diagnose because there is no definitive test for the condition and it develops slowly. In many cases confirming a diagnosis is a long process that can take years.

A diagnosis of AS is made by a doctor:

  • assessing symptoms experienced - back pain that does not improve with rest is a strong indicator that the person has AS
  • an examination
  • procedures e.g. genetic testing
  • scans
  • blood tests. If AS is suspected, a referral to a specialist (rheumatologist) is made

Blood Tests

No blood test can definitively prove or rule out a diagnosis of AS. However, blood tests can show signs of inflammation.

Scans

Scans may be used to examine the appearance of the spine and pelvis.

  • X-rays – creates images of the inside of the body, used to look for changes to the bones or joints
    • A diagnosis of AS can usually be confirmed if an X-ray shows inflammation of the sacroiliac joints (sacroiliitis) and at least 1 of the following:
      • at least 3 months of lower back pain that gets better with exercise and doesn't improve with rest
      • limited movement in the lower back (lumbar spine)
      • limited chest expansion compared with what is expected for age/sex
  • Ultrasound scans – uses sound waves to build up pictures of the inside of the body
  • Magnetic Resonance Imaging (MRI) scans – uses magnets to look at what is happening inside the body. Scan can show soft-tissue damage – in the muscles, ligaments or nerves – as well as any problems with the bones
  • Computerised Tomography (CT) scans – uses x-rays and a computer to create detailed images of the inside the body (sometimes called a CAT scan)

Genetic Testing

To test for the HLA-B27 gene - can contribute towards a diagnosis of AS.

References
1. NHS. Ankylosing spondylitis – Diagnosis. Available at https://www.nhs.uk/conditions/ankylosing-spondylitis/diagnosis Accessed October 2022
2. Mayo Clinic. Ankylosing spondylitis. Available at https://www.mayoclinic.org/diseases-conditions/ankylosing-spondylitis/diagnosis-treatment/drc-20354813 Accessed October 2022

There is no cure for AS, however treatment can help to relieve the symptoms and prevent or delay complications and spinal deformity.

There are three main ways to treat AS:

  1. Exercise
  2. Physiotherapy
  3. Medications

Exercise

It is extremely important to exercise and keep mobile with AS. Keeping active can improve posture and range of spinal movement, preventing the spine becoming stiff and painful.

Physiotherapy

  • Group or individual programmes – specific exercises to preserve good posture and movement
  • Massage – manipulation of muscles and other soft tissue to relieve pain and improve movement
  • Hydrotherapy – exercise in water helps make movement easier and the warm water can relax muscles

Medications

There are four main groups of medications that are used to treat AS:

  1. Painkillers – e.g., paracetamol, can help to relieve the pain

  2. Non-steroidal anti-inflammatory medications (NSAIDs) – e.g., ibuprofen, can be used to help control symptoms of pain, swelling or stiffness. They can be used in combination with painkillers

  3. Disease-modifying anti-rheumatic medications (DMARDs) – as well as treating symptoms, they can help prevent joint damage

    Biologics are a subset of DMARDs that target specific parts of the immune system causing joint damage. A biologic can slow, modify or stop the disease

References
1. NHS. Ankylosing spondylitis – Diagnosis. Available at https://www.nhs.uk/conditions/ankylosing-spondylitis/diagnosis Accessed October 2022
2. Mayo Clinic. Ankylosing spondylitis. Available at https://www.mayoclinic.org/diseases-conditions/ankylosing-spondylitis/diagnosis-treatment/drc-20354813 Accessed October 2022

Lifestyle changes can help with managing AS and include:

Exercise – lack of exercise may stiffen joints and weaken muscles. Exercise can also help ease pain and maintain flexibility

Posture – practicing standing straight in front of a mirror can help avoid some of the problems associated with AS

Smoking – creates additional problems including further hampering breathing

Medication – it is important to take medication as prescribed, even if symptoms reduce. Medication can help prevent flare-ups and reduce the risk of joint damage

References
1. Mayo Clinic. Ankylosing spondylitis. Available at https://www.mayoclinic.org/diseases-conditions/ankylosing-spondylitis/diagnosis-treatment/drc-20354813 Accessed October 2022

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