Axial spondyloarthritis (axSpA) is a chronic inflammatory condition that primarily affects the spine and the sacroiliac joints, which connect the spine to the pelvis. This condition can lead to pain, stiffness, and physical limitations. Understanding axSpA involves recognizing its nature, symptoms, diagnosis, and management.
What Axial Spondyloarthritis Is
Axial spondyloarthritis is a type of inflammatory arthritis that targets the axial skeleton, encompassing the spine, chest, and pelvis. It is a chronic and progressive condition. The condition involves the immune system mistakenly attacking healthy tissues, leading to inflammation and damage. This immune system dysregulation causes inflammation where ligaments and tendons attach to bone, a process called enthesitis.
AxSpA includes two main classifications: non-radiographic axial spondyloarthritis (nr-axSpA) and radiographic axial spondyloarthritis. Non-radiographic axSpA signifies that inflammation is present, but visible structural changes to the sacroiliac joints are not yet apparent on X-rays. Radiographic axSpA, also known as ankylosing spondylitis (AS), indicates that such changes are detectable on X-ray imaging. If left untreated, axSpA can cause vertebrae in the spine to fuse together, a process known as ankylosis, which can reduce spinal flexibility.
Common Symptoms
The primary symptom of axial spondyloarthritis is inflammatory back pain, which differs from common mechanical back pain. This pain typically has a gradual onset, often before 45 years of age, and persists for at least three months. It worsens with rest or inactivity, particularly at night or in the morning, and improves with exercise. Severe, prolonged morning stiffness is also common.
Beyond back pain and stiffness, fatigue is common. Inflammation can also affect peripheral joints like hips, shoulders, knees, and ankles, causing pain and swelling. Enthesitis, or inflammation where tendons and ligaments attach to bone, frequently causes pain in areas such as the Achilles tendon or plantar fasciitis. Some individuals may also develop uveitis, an eye inflammation causing pain, redness, and light sensitivity.
How Axial Spondyloarthritis Is Diagnosed
Diagnosing axial spondyloarthritis involves a comprehensive evaluation due to the varied presentation of symptoms and the lack of a single definitive test. The process typically begins with a detailed medical history, where a healthcare provider inquires about symptom characteristics, onset, and any family history of axSpA or related inflammatory conditions. A physical examination follows, assessing spinal mobility, tenderness in affected joints, and checking for other signs like psoriasis or eye inflammation.
Imaging studies are an important part of the diagnostic process. X-rays of the sacroiliac joints and spine are used to identify structural changes, which are characteristic of radiographic axSpA (ankylosing spondylitis). Magnetic resonance imaging (MRI) is also utilized for detecting inflammation in the sacroiliac joints and spine that may not yet be visible on X-rays, which is relevant for diagnosing non-radiographic axSpA.
Blood tests may be conducted to check for inflammatory markers such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), though these can be elevated for other reasons. The HLA-B27 genetic marker is often tested, as it is found in many people with axSpA, but its presence alone does not confirm a diagnosis. Diagnosis can sometimes be delayed because early symptoms may be mistaken for more common types of back pain.
Treatment Approaches
Managing axial spondyloarthritis typically involves a combination of pharmacological and non-pharmacological interventions aimed at reducing pain, stiffness, and preventing disease progression. Nonsteroidal anti-inflammatory drugs (NSAIDs) are often the initial treatment choice for managing pain and inflammation. These medications can significantly improve symptoms, and some studies suggest continuous use might help slow radiographic progression.
If NSAIDs do not provide sufficient relief, or if the disease is more active, biological disease-modifying antirheumatic drugs (bDMARDs) may be prescribed. Tumor necrosis factor (TNF) inhibitors are a common type of biologic; if these are not effective, interleukin-17 (IL-17) inhibitors may be considered. Conventional synthetic DMARDs, such as sulfasalazine, are generally used if peripheral joints are affected, rather than primarily for spinal symptoms. Corticosteroids may be injected directly into specific affected joints for localized inflammation but are not typically used orally for long-term management of axSpA.
Non-pharmacological approaches are also important. Regular physical therapy and exercise are recommended to maintain spinal flexibility, improve posture, and reduce pain. Lifestyle modifications, including not smoking and maintaining a healthy diet, can also support overall well-being and help manage inflammation. These combined strategies help individuals manage symptoms and maintain an active life.