Axial Spondyloarthritis (AxSpA) and Ankylosing Spondylitis (AS)

2025/09/23

What is Axial Spondyloarthritis and Ankylosing Spondylitis?

Axial spondyloarthritis (AxSpA) is a type of arthritis mainly affecting the spine (back-bone) and the buttocks (sacroiliac joints). Damaged joints lead to stiffening of the spine and loss of flexibility of the back. Ankylosing spondylitis (AS) is a subset of AxSpA and occurs in patients with X-ray changes in the joints in the buttocks (sacroiliac joints). AxSpA usually affects teenagers and young adults less than 40 years old, and is more common in men.

What causes AxSpA?

AxSpA is an autoimmune condition. The cause of AxSpA is unknown, but genetic factors exist, particularly with the presence of the HLA B-27 gene in 90% of patients with AxSpA.

What are the symptoms of AxSpA and AS?

• Back pain and stiffness, which usually starts from the lower back, buttock or neck, and persists over several months. The pain is usually worse in the morning and may wake you up at night. Rest does not make it better but exercise eases the pain.

• Other joints may be affected leading to joint pain, swelling and stiffness

• Tendons and ligaments may be affected leading to pain that is worse with specific movements e.g. pain over the back of the heel where the Achilles tendon inserts (tendoachilles tendinitis), sole of the feet (plantar fasciitis) and around the elbow (tennis elbow or golfer’s elbow)

• Other symptoms may include:

o Eye involvement: The eye may become painful, red and inflamed with severe sensitivity to bright lights (acute anterior uveitis)

o Gastrointestinal involvement: Diarrhoea, blood in the stools which may occur to inflammation in the intestines

o Tiredness

How is AxSpA and AS diagnosed?

Diagnosis is made based on a combination of a patient’s symptoms, clinical examination, blood tests (such as raised inflammatory markers e.g. CRP) and imaging studies such as X-rays or MRI. A genetic test (for HLA B-27) may be performed.

Further evaluation by an ophthalmologist (eye doctor) or gastroenterologist (stomach and intestine doctor) may be required if there is suspicion of eye or gastrointestinal involvement respectively.

What is the treatment for AxSpA?

AxSpA is a chronic condition. Symptoms can be alleviated, and joint damage can be prevented by prompt and appropriate treatment. Delay in treatment can lead to limitation in movement of the spine/other joints and hunching of the back which may be permanent.

• Exercise is the cornerstone of treatment – regular stretching can help to reduce pain and stiffness. A physiotherapist will teach you specific exercise routines. In addition, non-spinal loading exercises such as swimming are very useful.

• Non-steroidal anti-inflammatory drugs (NSAIDs) help with pain control and reduction of inflammation.

• Biologics: These are targeted medications for patients with severe disease in whom other treatments including NSAIDs have failed. These are given subcutaneously (injection under the skin given to the thighs or abdomen) or through the veins. Examples include infliximab, adalimumab, golimumab, etanercept, secukinumab, and ixekizumab.

• Other disease-modifying anti-rheumatic drugs (DMARDs) may be given in select patients who have affected joints in the upper or lower limbs. Examples include sulfasalazine and methotrexate.

• Newer targeted synthetic DMARDs have been developed and are usually reserved for patients who have failed NSAIDs and one or more biologics e.g. tofacitinib and upadacitinib.

• Patients on DMARDs will require regular blood tests to monitor for any potential side effects.

AxSpA patients are at higher risk of comorbid conditions such as osteoporosis and cardiovascular disease. These conditions should be addressed as part of holistic care for AxSpA and AS. Certain vaccinations are recommended for patients on biologics to prevent common infections, such as influenza, pneumococcal, RSV and shingles.

What should I do if I have been diagnosed with AxSpA?

Lifestyle changes are an important aspect of management. You are strongly encouraged to work closely with your physician and play an active role in your care.

• Avoid smoking

• Exercise and stretch regularly

• Eat a balanced diet. Raw and partially cooked food should be avoided to reduce risks of infections if you are on DMARDs or biologics

• Lose weight if you are overweight

• Reach out for support – whether through friends, family, or support groups such as the National Arthritis Foundation

What should I do if I suspect I have AxSpA?

Seek a doctor’s advice. You may be referred to a specialist (rheumatologist) who will confirm the diagnosis and start you on appropriate treatment.

This condition is managed by the Division of Rheumatology and Allergy.