Ankylosing spondylitis

Ankylosing spondylitis (AS) is a type of arthritis of the spine. It causes inflammation between your vertebrae and in the joints between the spine and pelvis, although it can affect other joints. 

The causes of AS aren’t known, but it is likely that both hereditary and environmental factors play a role.

There’s a link between AS and the presence in the body of an antigen — a substance the body regards as potentially dangerous and against which it produces antibodies — called HLA-B27. The risk of developing ankylosing spondylitis if you are HLA-B27 positive is reportedly about 20%.

The disease usually begins between the ages of 20 and 40 and is about three times more common in men than women. 

What are its symptoms?

Early symptoms of AS include back pain and stiffness, which often start in early adulthood. Over time, AS can fuse your vertebrae, limiting movement. While some people have less acute symptoms that come and go, others suffer with constant, severe pain.

Symptoms, especially in the early stages, can be very similar to common back problems. 

AS symptoms include:  

  • Arthritis: AS causes symptoms in the back and spine, as well as joint pain in other parts of your body, such as your hips and knees. 
  • Back pain and stiffness: This is worse in the morning and at night, and is not eased with rest. 
  • Fatigue: If untreated, AS can make you feel tired and lacking in energy.
  • Enthesitis: A painful inflammation where a bone is joined to a tendon (tissue connecting muscles to bones) or a ligament (tissue connecting bones to bones).

How is it diagnosed? 

An AS diagnosis is typically based on your medical history and a physical examination. Your doctor may also recommend imaging or blood tests.

There’s no single test for AS, so diagnosis involves information from different sources, including:

  • Your history of the condition 
  • A physical examination
  • Blood tests, which may reveal inflammation

Inflammation tests include:

  • C-reactive protein (CRP)
  • Erythrocyte sedimentation rate (ESR)
  • Plasma viscosity (PV)

Your doctor may also order a blood test that may confirm the presence of the HLA-B27 gene. People with ankylosing spondylitis always test positive for HLA-B27, but, in many cases, so do some people who do not have it. A positive test may point to AS but it won’t confirm the diagnosis. 

X-rays can sometimes help to confirm the diagnosis in later stages and magnetic resonance imaging (MRI) scans may show changes in the spine or sacroiliac joints at an early stage of the disease.

What are your treatment options? 

There are remedies to ease pain and stiffness, but exercise and maintaining a good posture are important in keeping the spine mobile. This can help you live an active life.  

Treatments include:

  • Medication: Doctors most commonly use nonsteroidal anti-inflammatory drugs (NSAIDs) to threat AS. They can relieve inflammation, pain and stiffness. However, there are side effects such gastrointestinal bleeding. Your doctor may also suggest tumour necrosis factor (TNF) blockers. TNF is a cell protein that acts as an inflammatory agent in rheumatoid arthritis. TNF blockers target this protein to help reduce pain, stiffness, and tender or swollen joints. They are administered by injecting the medication under the skin or through an intravenous line.
  • Physical therapy can provide a number of benefits, from pain relief to improved physical strength and flexibility. 
  • Surgery: Your doctor may recommend surgery if you have severe pain or joint damage or the spine needs to be straightened. Most people with AS, however, don’t need surgery.

Can it be prevented? 

AS has no cure, but medication can relieve symptoms and may keep it from worsening. Eating a healthy diet, not smoking, and exercising can help. 

For more info

Visit the Arthritis Foundation of South Africa

The accuracy of this information was checked and approved by physician Dr Thomas Blake in May 2016