Ankylosing spondylitis
AS
This is a type of arthritis in which the joints of the spine are inflamed for a long time; usually the joints that connect the spine to the pelvis are affected, and occasionally other areas, such as the shoulders or buttocks, and eye and bowel problems can occur. Recurrent back pain is characteristic of stiff spondylitis. The stiffness of the affected spinal joints usually worsens over time.
It is believed that the etiology and genetic and environmental factors of stiff spondylitis are related, and more than 90% of patients have a specific human leukocyte antigen called HLA-B27 antigen, so it is thought to be associated with autoimmune or autoinflammatory diseases. In addition to the symptoms, the diagnosis of rigid spondylitis is usually supported by data from clinical imaging and blood tests. AS, unlike rheumatoid arthritis, is an axial spondyloarthropathy with negative serum rheumatoid factor antibodies.
There is no cure for stiff spondylitis, and symptomatic treatment includes medication, exercise, and surgery. Drugs include nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, disease-modifying antirheumatic drugs such as sulfasalazine, and biologics such as infliximab.
The incidence of AS is between 0.1 and 1.8%, and it is more likely to occur in young people, more often in men than in women. The incidence of AS in China is about 3%, the male-to-female ratio is about 2-3:1, and the onset of the disease is slower and milder in women; the age of onset of the disease is usually 13-31 years old, and the peak is 20-30 years. The incidence AS in Black populations is significantly lower than in East Asian and white people. In East Asia, the incidence rate of Japanese natives is 0.05-0.2%, which is significantly lower than that of China and South Korea.
Signs and symptoms
The main course of AS is inflammation of the joints and tendons, especially in the pelvis and spine, accompanied by edema and damage to the bone marrow, as well as ossification of the bone marrow. Symptoms usually develop gradually after the age of 20 years, and initially long-term spinal pain and stiffness are common with arthralgia in the lateral buttocks and back of the thighs, including tendon attachments and joint capsules. Granulation tissue grows below the articular cartilage, which forms infiltration through lymphocytes and macrophages. The damaged edges of the joint are replaced by fibrocartilage, which then becomes osseotic and the joint gradually stiffens. In the spine, this process causes ligamentous osteophytes to develop in the bones and to join adjacent vertebrae. Such a process can eventually lead to so-called bamboo-like spinal changes.
About 40% of patients will develop iritis, causing redness of the eyes, eye pain, blindness, and photophobia. Other complications include chest pain and fatigue.
The onset before the age of 18 often causes the joints of the extremities, especially the knees, to swell and be painful. Onset before puberty may involve swollen and painful ankle and foot joints and calcaneal spurs.
Treatment
- Nonsteroidal anti-inflammatory analgesics and antipyretic analgesics have good results. Sulfasalazine has obvious efficacy in improving low back stiffness and sacroiliac joint lesions.
- Severe peripheral joint lesions can also be treated with methotrexate. When hip lesions are severe, causing bony rigidity and paralysis, an artificial hip replacement is performed early to restore function.
- Rehabilitation training is of great significance for this disease.