Ankylosing Spondylitis - Symptoms, Causes, Diagnosis and Treatment
Ankylosing spondylitis, (pronounced ang·kee·low·zuhng spon·duh·lai·tuhs) is a chronic, inflammatory form of arthritis that primarily affects the spine, causing pain, stiffness, and loss of mobility. While the exact cause remains unknown, there are many treatment options available to help manage the condition and improve quality of life. This article provides a detailed overview of AS, covering its potential causes and symptoms, how it can be diagnosed and treatment options to help those affected better understand and live well with this condition.
What is Ankylosing Spondylitis?
Ankylosing spondylitis mainly affects the spine, especially the joints connecting the spine to the pelvis (called sacroiliac joints). It can also affect other areas like the hips, neck, and shoulders. AS is an autoimmune condition, meaning the immune system attacks part of the body – in this case causing inflammation in the spinal joints. This can lead to chronic pain and stiffness. Over time, this may cause some spine bones to fuse together, reducing flexibility and mobility.
Time for a quick terminology check in - it can get confusing! There are two main types of AS (also known as axial spondyloarthritis or axSpA):
- Radiographic axial spondyloarthritis (axSpA): This type, often called ankylosing spondylitis, shows on X-rays due to changes in the sacroiliac joints.
- Nonradiographic axial spondyloarthritis (nr-axSpA): In this type, symptoms fit AS but don’t show on X-rays. It may represent early AS with milder symptoms.
AS affects about 0.1-1.4% of people worldwide1. It’s often more frequently diagnosed in men, but this difference may be partly due to how symptoms are identified and treated2.
While AS is not curable, many people manage it with the right combination of treatments and lifestyle changes.
What causes Ankylosing Spondylitis?
The exact cause of AS isn’t fully understood, but genes are thought to play a part. In particular, A gene called HLA-B27 contributes around 20% to the likelihood of developing AS, and over 100 other genes may also contribute3. However, not everyone with this gene will develop the condition, so other factors are likely involved.
Central sensitization, where the nervous system becomes more sensitive to pain can worsen pain and cause it to spread beyond the spine4.
AS doesn't come from aging, about 80% of people with AS have symptoms before age 305.
Ankylosing Spondylitis symptoms
AS symptoms can vary in intensity and may be constant or come in “flares”. Key symptoms include:
- Pain and stiffness: Typically in the lower back, hips, and buttocks, especially after rest. Unlike other back pain, symptoms often improve with exercise. Pain usually starts gradually before age 30 and lasts for over three months, becoming chronic. While mostly in spine joints, people can also experience pain in associated joints such as pain in feet, hands, ribs, hips and neck.
- Loss of mobility: In severe cases, over time, vertebrae may fuse together, reducing flexibility and increasing stiffness.
- Fatigue: Chronic inflammation can drain energy, leading to constant tiredness.
- Other complications: AS can affect other body areas, causing:some text
- Eye inflammation (uveitis)
- Bone weakness (including the development over time of osteoporosis), leading to fractures
- Breathing issues when ribs are affected
- Cardiovascular problems in 2-10% of cases6
- Nerve damage can occur as a secondary complication of AS due to factors like bone growth or surgeries involving spinal fusion
- Digestive issues like inflammatory bowel disease
- Skin rashes such as psoriasis
- Mental health impacts, including sleep issues, depression, and anxiety
How to diagnose Ankylosing Spondylitis
Diagnosing AS usually includes several steps:
- Medical history and physical examination: Your doctor will ask about your symptoms, such as the location of pain, how long you have had it,and what activities might ease it. They’ll also ask about your family history and check how freely you can move.
- Imaging tests: X-rays, CT scans, or MRIs can show inflammation and changes in the spine and sacroiliac joints. These tests can be both to determine a baseline for progression and to check for and rule out other causes for your pain (such as lumbar spinal stenosis and rheumatoid arthritis). These images can help set a baseline for tracking AS over time and rule out other causes of pain, like spinal stenosis or rheumatoid arthritis. If severe bone fusion is seen, it's sometimes called “bamboo spine.”
- Blood tests: These may look for the HLA-B27 gene and signs of inflammation, like C-reactive protein (CRP). Although the HLA-B27 gene is commonly found in people with AS, not all individuals with this gene will develop the condition, so it’s not required for a diagnosis.
- General health: Your doctor may also ask about any other inflammatory conditions, like IBS or psoriasis, which often occur with AS.
AS can be diagnosed by a general practitioner, but sometimes a rheumatologist—who specializes in conditions affecting joints, bones, and muscles—will confirm it.
A study of AS prevalence in the UK noted it takes about six years on average to get an AS diagnosis after symptoms start. This is because back pain is common, AS is complex, and it can take time to see a specialist7.
Ankylosing Spondylitis Test
Now for the diagnostic terminology and jargon….. These indices were developed by a team of rheumatologists, physiotherapists, and research associates with a specialist interest in AS at the Royal National Hospital for Rheumatic Diseases (RNHRD) for diagnostic purposes8.
- Bath ankylosing spondylitis disease activity index (BASDAI): Six questions about symptoms in the past week.
- Bath Ankylosing Spondylitis Functional Index (BASFI): Ten questions about how AS affects your daily activities.
- Bath Ankylosing Spondylitis Metrology Index (BASMI): Measures changes in spine movement and is widely used in research.
- Bath Ankylosing Spondylitis Global Score (BAS-G): Two questions about overall wellbeing.
- Ankylosing Spondylitis Disease Activity Score (ASDAS)9 - A combination of other scores to show AS activity levels, from inactive to very high.
- Ankylosing Spondylitis Disease Activity Score–CRP (ASDAS-CRP) - a combined index that includes self assessment of back pain, duration of morning stiffness and amount of joint swelling as well as a biologic marker of inflammation levels.
Conditions related to ankylosing spondylitis
AS mainly causes pain and stiffness in the spine, and it can seem similar to other back pain conditions. But AS is different from regular back pain because it often includes these key features:
- Alternating buttock pain
- Uneven joint pain (affecting one side more than the other)
- Heel pain
- Eye inflammation (uveitis)
- Family history of AS
- Pain relief from non-steroidal anti-inflammatory drugs (NSAIDs)
If one or two of these symptoms are present, there’s a 35–70% chance it could be AS. Having three or more of these features increases the chance to 80–95%10.
Other conditions, like scoliosis, Bertolotti's syndrome, and psoriatic arthritis, can also cause back pain but have different causes and require different treatments.
“Red flags” for back pain
There are some “red flags” for back pain that should never be ignored, whether or not AS is the cause. If you have difficulty urinating, lose bowel control, feel numb in your lower body, or suddenly find it hard to walk, get medical help right away. These can be signs of a serious condition called cauda equina syndrome. Other red flags include:
- A recent serious injury
- Weight loss without trying
- History of cancer
- Fever with back pain
- Use of IV drugs or steroids
- Severe pain at night
- Worsening numbness or tingling
- Morning stiffness lasting over 30 minutes
Ankylosing Spondylitis treatment
While there isn’t a cure for AS, gaining a deep understanding of your pain system and creating a tool-box of effective, evidence-based strategies will help you to become your very own expert. AS treatment aims to manage symptoms and improve life quality. A few approaches can help:
Education: Understanding the nature of AS and how to manage symptoms effectively can can make a big difference11.
Physical therapy: Regular movement helps reduce stiffness, improve mobility, and prevent complications. Studies show that physical activity is safe and helpful for people with AS12. And, an additional bonus, being active can improve your mood!
Pain psychology: Techniques like Cognitive Behavioral Therapy (CBT), Acceptance and Commitment Therapy (ACT), and mindfulness can help manage the emotional side of living with chronic pain13. AS is often linked with mental health conditions like depression and anxiety, so learning new ways to think about and handle AS can be very helpful, particular in the area of developing resilience and coping strategies14.
Medication: Some medications can help manage inflammation and pain, such as over-the-counter NSAIDs (like ibuprofen) and corticosteroids. Biological treatments, like IL-17A inhibitors (e.g., secukinumab) and TNF inhibitors, are newer options that may help if exercise and NSAIDs aren’t enough15,16.
Living with Ankylosing Spondylitis
AS is an inflammatory condition, so certain lifestyle changes can help manage symptoms. Chronic pain is complex and can be influenced by more than just joint inflammation.
Here are some lifestyle tips for living well with AS:
Stay active: Motion is lotion! Moving your body is important, whether it’s swimming, tai chi/qigong, yoga, or more intense activities like cycling or golf. Keeping joints moving can help reduce stiffness. inflammation.
Diet: Carrying extra weight can place further strain on affected joints, while too little body fat may increase fatigue, anemia, and inflammation. So eating nutritious foods, maintaining a healthy weight, and cutting down on processed foods, saturated fats, and sugar can help reduce discomfort and inflammation. An anti-inflammatory diet, rich in omega-3 fatty acids and antioxidants, may help manage symptoms however at this stage, there is insufficient evidence that diet can influence AS activity17.
Sleep: Good sleep helps lower inflammation and boost mood and that all sounds pretty good, right? AS often causes nighttime pain and stiffness, making it harder to get deep, restorative sleep. Establishing healthy sleep habits, such as setting a regular sleep schedule and creating a comfortable sleep environment, can make a big difference.
Smoking: Quitting smoking can be very helpful, as smoking worsens AS symptoms and speeds up damage18.
Reduce stress: For any condition where central sensitization or chronic pain plays a role, it is important to keep your levels of stress as low as possible. Stress reduction activities like deep breathing, mindfulness, meditation or other relaxation strategies are likely to be helpful lifestyle approaches for managing AS symptoms.
Conditions like AS can be managed really well, but they also have to be managed for a lifetime. Which means you’ll experience ups and downs along the way. Building a “toolbox” of strategies for managing symptoms can make a big difference, especially during flare-ups.
Resources and support for Ankylosing Spondylitis
There are many resources available to help those living with AS, such as the Spondylitis Association of America, Arthritis Australia, Musculoskeletal Health Australia.
These groups offer information on treatment, support groups, and lifestyle tips.
Looking for more help?
Living with AS can be challenging, but with the right approach, you can manage your symptoms and improve your quality of life.
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