Ankylosing Spondylitis (AS)

What is Ankylosing Spondylitis?

Ankylosing spondylitis (AS), also known as axial spondyloarthritis (SpA) in Singapore, is a chronic inflammatory condition that mainly affects the spine. It leads to pain, stiffness, and reduced mobility in the back. It falls under the category of spondyloarthritis, a group of autoimmune diseases that affects the joints of the spine,  joints in the limbs, tendons and the entheses (sites where tendons and ligaments attach to bone).

Ankylosing spondylitis predominantly affects the sacroiliac joints and lumbar spine (lower back) initially, though it can also affect the cervical and thoracic spine. Prolonged inflammation in these areas can ultimately lead to spinal fusion, resulting in a rigid spine known as bamboo spine. The condition may also affect other joints, tendons, and ligaments. Some people with ankylosing spondylitis develop eye disease (uveitis), or rarely gut disease (inflammatory bowel disease).

Ankylosing spondylitis is two to three times more common in males than females. It usually starts in the teenage years and early adulthood and can lead to persistent discomfort and limitations in daily activities.

What causes Ankylosing Spondylitis?

Thus far, there has been no definitive proof of an exact cause of ankylosing spondylitis, but it is believed to result from a combination of genetic and environmental factors.  The primary genetic factor associated with AS is the presence of a specific gene called HLA-B27. Almost 90% of people with AS are positive for this gene. However, not everyone with HLA-B27 gene develops AS, only 1-5% of HLA-B27 positive individuals in the population develop AS.  Environmental factors, such as infections or other triggers, may play a role in the development of AS in genetically predisposed individuals.

What are the symptoms of Ankylosing Spondylitis?

Symptoms of ankylosing spondylitis include the following: 

• Back pain: persistent, chronic painin the lower back and/or buttocks. This pain is worse in the morning or with prolonged inactivity.
• Stiffness: stiffness in the spine, especially in the morning or after rest. The stiffness improves with movement and exercise.
• Reduced spinal mobility: ankylosing spondylitis can lead to decreased flexibility in the spine, making it challenging to bend or twist. Over time, the fusion of spinal vertebrae can lead to a rigid spine known as “bamboo spine”.Peripheral joint pain: ankylosing spondylitis can also cause pain and swelling in joints other than your spine. This can include your, ankles, knees, hips and shoulders.
• Enthesitis: enthesitis refers to inflammation at the sites where your tendons and ligaments attach to the bone. This can cause pain and tenderness in these areas.
• Chest pain: inflammation of the joints between the ribs and breastbone (costochondritis) can cause chest pain.
• Eye inflammation: 20-30% of individuals with ankylosing spondylitis may develop uveitis (eye inflammation). Symptoms of this include eye pain, redness, and sensitivity to light.
• Limited chest expansion: ankylosing spondylitis can restrict the expansion of your chest, leading to shallow breathing.
• Fatigue: many individuals with ankylosing spondylitis report feeling fatigued, even after a whole night’s sleep.
• Weight loss: unintentional weight loss due to loss of appetite and inflammation is a common symptom of ankylosing spondylitis.
• Inflammatory bowel disease: individuals with ankylosing spondylitis rarely develop Crohn’s disease or ulcerative colitis

If you suspect you have ankylosing spondylitis or are experiencing any of the symptoms mentioned above, make an appointment with Asia Arthritis Rheumatology Clinic today.

Is Ankylosing Spondylitis painful?

Yes, ankylosing spondylitis is painful. It is a chronic inflammatory condition that primarily affects the spine and the sacroiliac joints, causing pain and stiffness. The pain is often described as a dull ache and varies in intensity. People with ankylosing spondylitis may experience pain and discomfort in the lower back, buttocks, and sometimes the neck and peripheral joints.

The pain tends to worsen in the morning or after prolonged periods of inactivity, but it may improve with physical activity and exercise. Ankylosing spondylitis-related pain can also lead to disrupted sleep, fatigue, and reduced quality of life. In severe cases, the inflammation can result in the fusion of spinal vertebrae, further limiting mobility and causing chronic pain.

Who is at risk of Ankylosing Spondylitis in Singapore?

Ankylosing spondylitis is a condition that can affect anyone, but certain factors can increase the risk of developing ankylosing spondylitis in Singapore. These risk factors are:

• Genetics: ankylosing spondylitis has a strong genetic component. If you have a family member with ankylosing spondylitis, your risk of developing the condition is heightened. Specific genetic markers like HLA-B27 are associated with a higher risk.
• Age: ankylosing spondylitis typically manifests in late adolescence or early adulthood, typically before the age of 45
• Gender: ankylosing spondylitis is two to three times more common in men than women.
• Altered gut bacteria: individuals with altered gut bacteria are more likely to develop ankylosing spondylosis.
• Infections: studies have shown that individuals with previous infections are at an increased risk of developing ankylosing spondylitis.
• Smoking: smoking has been linked to many medical conditions, including ankylosing spondylitis.

While these factors may increase your risk, it is important to note that not everyone with these risk factors will develop ankylosing spondylitis, and individuals without them can still develop the condition.

How is Ankylosing Spondylitis diagnosed?

Diagnosing ankylosing spondylitis involves a combination of medical history, physical examinations, and various tests.

Diagnosing ankylosing spondylitis typically includes:

• Medical history: your rheumatologist will start by taking a detailed medical history and ask about your symptoms, family history of ankylosing spondylitis, and any previous illnesses or infections. This information helps to build a diagnostic foundation for your condition.
• Physical examination: a physical exam is conducted to assess your range of motion and flexibility and to look for signs of inflammation, especially in your spine and joints.
• Blood tests: while there is no definitive blood test for ankylosing spondylitis, genetic markers, such as HLA-B27 can provide supportive evidence for your diagnosis.
• Imaging tests: X-rays and magnetic resonance imaging (MRI) scans are crucial for ankylosing spondylitis diagnosis. X-rays can reveal structural changes in the spine or affected joints. MRI scans can detect inflammation or early signs of ankylosing spondylitis, especially inflammation in the affected areas.

Ankylosing spondylitis can be challenging to diagnose, and it may take time to rule out other conditions with similar symptoms. Early diagnosis is crucial for managing ankylosing spondylitis effectively.

If you suspect you have ankylosing spondylitis or are experiencing symptoms such as pain and stiffness in your lower back or finding it difficult to take deep breaths, consult  a rheumatologist for a proper evaluation and diagnosis.

What are the treatment options for Ankylosing Spondylitis in Singapore?

In Singapore, ankylosing spondylitis is treated through a combination of approaches to relieve symptoms, improve mobility, and slow down the condition's progression.

Treatment options include:

• Medications:
  • Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly prescribed to manage pain and inflammation. Continuous treatment with NSAIDs appears to reduce the progression of spinal disease in AS.  
  • Disease-modifying antirheumatic drugs (DMARDs), such as sulfasalazine may be used in some cases, depending on the joints involved and severity of the condition.
  • Corticosteroids are occasionally helpful in controlling AS symptoms; however, they should only be used for the short term.
  • Biologics, such as tumour necrosis (TNF) inhibitors, IL-17 inhibitors, and Janus kinase (JAK) inhibitors, may be recommended.
• Physical therapy: physical therapy and regular exercises help maintain flexibility and posture, reducing pain and stiffness.
• Lifestyle modifications: good posture, ergonomic workstations, and lifestyle changes can alleviate discomfort.
• Heat and cold therapy: applying heat or cold packs can relieve pain and inflammation.
• Surgery: in severe cases or when joint damage is significant, surgery may be considered to correct deformities or replace damaged joints.

Treatment plans should be personalised and regularly reviewed by your rheumatologist.

Frequently Asked Questions