Non-radiographic axial spondyloarthritis (nr-axSpA) and ankylosing spondylitis (AS) are both subtypes of axial spondyloarthritis that are diagnosed and treated in similar ways.
Axial spondyloarthritis is a type of chronic arthritis that can cause inflammation in your spine, sacroiliac (SI) joints, and peripheral joints, such as the joints in your:
- knees
- ankles
- shoulders
- elbows
- wrists
- hands
- feet
Your SI joints connect your pelvis to your lower spine.
Nr-axSpA and AS may cause swelling, stiffness, and pain in any of these joints. It may also cause enthesitis, which is inflammation where tendons or ligaments attach to bone.
Nr-axSpA and AS may cause inflammation in other tissues and organs, such as your gastrointestinal (GI) system, skin, and eyes.
Treatment is important to help reduce inflammation, relieve symptoms, and lower your risk of complications, including permanent joint damage.
Read on to find answers to common questions about the differences between nr-axSpA and AS.
Nr-axSpA is a subtype of axial spondyloarthritis that may affect your spine, SI joints, peripheral joints, and other areas of your body. Your SI joints connect your pelvis to your lower spine.
Both nr-axSpA and AS may cause inflammation, stiffness, and pain in your SI joints. However, X-ray images only show definitive damage to the SI joints in AS. This is the defining difference between the two conditions.
Some people with nr-axSpA experience more frequent, widespread, or severe pain than others. This may include mild to severe pain in the SI joints, even when no damage is visible on X-rays.
Studies have found that nr-axSpA progresses to AS in
Treatment may help reduce inflammation, relieve symptoms, and limit disease progression.
AS is another subtype of axial spondyloarthritis that may affect your spine, SI joints, peripheral joints, and other tissues. It’s also known as radiographic axial spondylitis (axSpA).
AS causes definitive damage to the SI joints visible on X-rays.
Some people develop AS after living with a diagnosis of nr-axSpA for some time. Other people learn they have AS with no prior diagnosis of nr-axSpA.
To diagnose nr-axSpA or AS, your doctor will:
- ask you about your symptoms and medical history
- conduct a physical exam of your joints and other affected areas
- order blood tests to check for genetic markers and signs of inflammation
- order imaging tests of affected joints
These steps can help your doctor determine whether you have axial spondyloarthritis or nr-axSpA specifically.
Your doctor may order multiple imaging tests, including X-rays and an MRI.
If you have AS, definitive damage to your SI joints will appear on your X-rays.
If you have nr-axSpA, no definitive damage to your SI joints will appear on your X-rays. However, your MRI images may show active inflammation in your SI joints. This can help your doctor diagnose and treat nr-axSpA early, which helps stop it from progressing to AS.
Your doctor will also take steps to rule out other conditions that may cause inflammation or joint damage, such as:
- injuries
- infections
- other types of arthritis
- other chronic pain conditions, such as fibromyalgia
The general treatment approach is similar for nr-axSpA and AS, but there are more Food and Drug Administration (FDA)-approved medications for AS.
Sometimes, a doctor may prescribe a treatment for nr-axSpA or AS that isn’t specifically FDA-approved for that condition. This is known as off-label prescribing.
The first-line treatment for nr-axSpA and AS is a combination of physical therapy and nonsteroidal anti-inflammatory drugs (NSAIDs).
If you continue to experience inflammation despite these treatments,
- adalimumab (Humira)
- infliximab (Remicade)
- etanercept (Enbrel)
- certolizumab pegol (Cimzia)
- golimumab (Simponi)
The FDA has approved all these TNF inhibitors for AS. It has approved Cimzia only for nr-axSpA, but your doctor might prescribe another TNF inhibitor off-label.
If treatment with a TNF inhibitor doesn’t work well for you, your doctor may prescribe:
- an interleukin (IL)-17A inhibitor, such as:
- secukinumab (Cosentyx)
- ixekizumab (Taltz)
- a Janus kinase (JAK) inhibitor, such as:
- tofacitinib (Xeljanz)
- upadacitinib (Rinvoq)
The FDA has approved Cosentyx, Taltz, and Rinvoq for nr-AxSpA and AS. But Xeljanz is only approved for AS.
Other potential treatments for nr-axSpA and AS include:
- conventional disease-modifying drugs for peripheral arthritis, such as:
- sulfasalazine
- methotrexate
- local corticosteroid injections
- surgery for severe joint damage
Researchers are also continuing to develop and test new treatments for nr-axSpA and AS.
Your doctor may also recommend certain lifestyle changes or home remedies to help manage pain, stiffness, or other symptoms. Talk with your doctor before trying a new home remedy.
Your doctor may refer you to another specialist if you develop GI, skin, or eye symptoms. Certain medications that reduce joint inflammation may also reduce inflammation in other organs.
Members of your care team should work together to develop a treatment plan that addresses symptoms across all affected organ systems.
Nr-axSpA and AS may cause similar symptoms, ranging from mild to severe. Some people with nr-axSpA have symptoms just as severe as those experienced in AS.
Both conditions can reduce quality of life, limit physical function, and contribute to disability.
Either condition may become more severe over time, especially without treatment.
Chronic inflammation can lead to permanent joint damage, which may require surgery to treat.
Nr-axSpA progresses to AS in an estimated
Treatment can help reduce inflammation, relieve symptoms, and limit disease progression and joint damage. Lowering inflammation can also help reduce your risk of heart disease.
Talk with your doctor to learn more about your outlook and treatment options.
Nr-axSpA and AS are subtypes of axial spondyloarthritis, a chronic condition that causes inflammation in joints such as your spine, SI joints, and peripheral joints. It may also cause inflammation in your gastrointestinal tract, skin, eyes, or areas where tendons and ligaments attach to bone.
The key difference between the two conditions is that nr-axSpA doesn’t involve definitive damage to the SI joints on x-rays, whereas AS does.
Let your doctor know if you’re experiencing chronic back pain, pain or stiffness in other joints, or signs or symptoms of inflammation in other parts of your body.
They may ask you about your symptoms and medical history, conduct a physical exam, and order blood and imagining tests to determine the cause.
The first-line treatment for nr-axSpA and AS is physical therapy combined with NSAIDs. Your doctor may prescribe other medication if these treatments don’t work.
Treatment can reduce inflammation, relieve symptoms, and help prevent disease progression and complications. Talk with your doctor to learn more about your diagnosis, treatment options, and outlook.