What are the characteristics of ankylosing spondylitis?

In general, the characteristics of ankylosing spondylitis may include preferential involvement of the sacroiliac joints, inflammatory back pain, chronic progressive disease course, strong association with the HLA-B27 gene, and possible extra-articular manifestations. Detailed analysis is as follows:

1. Preferential involvement of the sacroiliac joints: The sacroiliac joints are the earliest and primarily affected sites in this disease. Inflammation initially attacks these areas, and patients often experience pain and stiffness in the lower back or sacroiliac region at an early stage. Obvious tenderness may be present upon palpation of the sacroiliac joints. As the disease progresses, inflammation gradually spreads upward to the lumbar spine, thoracic spine, and cervical spine.

2. Inflammatory back pain: Patients experience typical inflammatory back pain, characterized by significant morning stiffness that improves gradually after activity lasting more than 30 minutes. Pain worsens during rest and improves with activity. Nighttime pain is often more pronounced and may even disrupt sleep.

3. Chronic progressive disease course: The disease has a slow, insidious onset and progresses in a chronic, persistent manner. Early symptoms may be mild and include occasional low back discomfort, which can be easily overlooked. If not treated promptly, inflammation continues to damage the spinal and joint structures, eventually leading to spinal rigidity and joint fusion.

4. Strong association with the HLA-B27 gene: This disease has a clear genetic link. About 90% of patients test positive for the human leukocyte antigen B27 (HLA-B27), whereas only 5%-10% of the general population are HLA-B27 positive.

5. Possible extra-articular manifestations: In addition to symptoms affecting the spine and joints, some patients may experience extra-articular manifestations. The most common of these is eye inflammation, presenting as redness, pain, photophobia. A minority of patients may also develop intestinal inflammation or skin lesions, and these extra-articular manifestations may sometimes appear before joint symptoms.

In response to these characteristics, it is important to pay attention to the nature of low back pain in daily life and seek timely evaluation if inflammatory back pain is suspected. Once diagnosed, consistent and standardized treatment should be followed to slow disease progression. Regular monitoring of the eyes, intestines, and other areas is also essential for early detection and management of extra-articular manifestations to maintain overall health.