Ankylosing spondylitis (AS) is a type of spondyloarthritis characterized by chronic inflammation of the spine and pelvis. It can lead to pain, stiffness, and fusion of vertebrae and other joints. Spondyloarthritis (SpA) is a group of inflammatory disorders that includes AS, but also other inflammatory diseases.
Ankylosing spondylitis (AS) is a type of arthritis in which inflammatory processes lead to stiffness and fusion of vertebrae and other joints. Because AS involves axial (spine) changes detected with radiographic imaging, it can also be called radiographic axial spondyloarthritis.
- Inflammatory back pain, which may alternate between sides of the low spine
- Sleep disturbances due to back pain
- Morning stiffness that improves with movement
- Eye inflammation
- Inflammatory bowel disease
Diagnosis of AS is based upon a combination of clinical, laboratory, and imaging findings characteristic of the disease alongside the exclusion of other relevant diagnoses such as chronic mechanical back pain, fibromyalgia, or sacroiliac joint infection.
Drugs that limit inflammation, such as non-steroidal anti-inflammatory drugs (NSAIDs), or if necessary, tumor necrosis factor alpha (TNF-alpha) inhibitors or interleukin 17 (IL-17) inhibitors. Physical therapy is often prescribed to improve balance and mobility.
Although some research has been conducted, there isn’t much conclusive evidence. One small trial found that high doses of omega-3 fatty acids reduced AS disease activity, and another found that nanocurcumin reduced the expression of inflammatory markers in people with AS. High serum Vitamin D is correlated with lower risk and severity of AS, but no causal evidence for this relationship exists. Finally, calcium may support bone health for people with AS and osteoporosis, but it doesn’t seem to directly influence AS itself.
Although 78% of individuals with AS believe diet influences their symptoms, individual preferences and sensitivities vary. A low starch diet has been proposed to reduce Klebsiella bacteria, which has been implicated in triggering spondyloarthritis activity. Research suggests the diet is effective for AS management, and results in reductions of disease activity and reliance on NSAIDs.
Symptom management strategies vary based on individual needs and the presence of comorbidities. Research suggests exercise programs can reduce AS disease activity and improve quality of life.
Although the cause of AS is unknown, genetics play a large role in an individual’s susceptibility. In particular, the human leukocyte antigen HLA-B27 is strongly correlated with AS. Men are more likely to present with the radiographic signs of AS, but spondyloarthritis occurs with a more even frequency. The absence of radiographic indications among women can result in a diagnostic delay, during which time the disease can progress unmanaged.