How to diagnose ankylosing spondylitis? Be careful if these situations occur!

Ankylosing spondylitis is a bone disease that causes inflammation around the human spine. It is a chronic disease. Generally, people with ankylosing spondylitis are prone to symptoms of physical fatigue and weight loss. It is more common in young people between the ages of 30-35. It can also easily lead to mild anemia. As the disease slowly progresses, pain will appear in the spinal joints and muscles will become stiff, especially at night when the pain will worsen and may become uncontrollable. It requires timely treatment, and appropriate physical exercise should be done to maintain muscle mobility and replenish the body with nutrients and trace elements.

Clinical manifestations of ankylosing spondylitis

1. Initial symptoms

For young people aged 16 to 25, especially young men. Ankylosing spondylitis generally has an insidious onset and may not have any clinical symptoms in the early stages. Some patients may show mild systemic symptoms in the early stages, such as fatigue, weight loss, long-term or intermittent low fever, anorexia, mild anemia, etc. As the disease is relatively mild, most patients cannot detect it early, resulting in delayed disease progression and loss of the best time for treatment.

2. Manifestations of joint disease

AS patients often have joint lesions, and most of them first invade the sacroiliac joints and then progress upward to the cervical spine. In a small number of patients, the cervical spine or several spinal segments are first affected, and the surrounding joints may also be affected. In the early stage, there is inflammatory pain in the joints at the lesion site, accompanied by muscle spasms around the joints and a feeling of stiffness, which is more obvious in the morning. It may also manifest as night pain, which is relieved by activity or taking analgesics. As the disease progresses, joint pain decreases, but the movement of each spinal segment and joint becomes restricted and deformed. In the late stage, the entire spine and lower limbs become rigid, arched, and bent forward.

(1) Sacroiliitis: About 90% of AS patients first present with sacroiliitis. Later it develops upward to the cervical spine, manifesting as recurrent low back pain, stiffness in the lumbar region, intermittent or alternating low back pain and pain in both buttocks, which may radiate to the thighs. There are no positive physical signs, and the straight leg raising test is negative. However, direct pressure or stretching of the sacroiliac joint may cause pain. Some patients have no symptoms of sacroiliitis, and only abnormal changes are found in X-ray examinations. About 3% of AS first affect the cervical spine and then spread downward to the lumbar sacral region. In 7% of AS, almost the entire spine is affected simultaneously.

(2) Lumbar spine disease When the lumbar spine is affected, most symptoms include limited movement of the lower back and waist. Lumbar flexion, extension, lateral bending and rotation may all be limited. Physical examination may reveal tenderness of the lumbar spinal processes and paralumbar muscle spasm; in the later stages, lumbar muscle atrophy may occur.

(3) Thoracic vertebrae disease When the thoracic spine is affected, symptoms include back pain, anterior chest pain, and lateral chest pain, with the most common deformity being kyphosis. If the costovertebral joints, manubrium-sternosal joints, sternoclavicular joints and intercostal cartilage joints are affected, the chest pain will be band-like, the chest expansion will be limited, and the chest pain will be aggravated when inhaling, coughing or sneezing. In severe cases, the chest cavity remains in the exhalation state, and the chest expansion is reduced by more than 50% compared with normal people, so it can only be assisted by abdominal breathing. Due to the reduction in the capacity of the chest and abdominal cavity, heart, lung and digestive functions are impaired.

(4) A small number of patients with cervical spondylosis first present with cervical spondylitis, with pain in the cervical spine that radiates along the neck to the head and arms. The neck muscles initially spasm and then atrophy, and the disease may progress to kyphosis of the cervical and thoracic spine. The movement of the head is significantly limited, and it is often fixed in a flexed position and cannot be tilted upward, bent sideways or rotated. In severe cases, patients can only see a small piece of ground in front of their toes and cannot lift their heads to look straight ahead.

(5) Peripheral joint lesions: About half of AS patients have transient acute peripheral arthritis, and about 25% have permanent peripheral joint damage. It usually occurs in large joints and more often in the lower limbs than in the upper limbs. When the shoulder joint is affected, joint movement is limited, the pain is more obvious, and activities such as combing the hair and raising the hands are restricted. When the knee joint is invaded, the joint will bend compensatorily, making daily life such as walking and sitting more difficult. It rarely affects the elbow, wrist and foot joints.

In addition, the pubic symphysis may also be affected, and the upper edge of the pelvis, ischial tuberosity, greater trochanter of the femur and heel may have symptoms of osteitis, which manifests as local soft tissue swelling and pain in the early stage and bone enlargement in the late stage. Generally, peripheral arthritis may occur before or after spondylitis. The local symptoms are difficult to distinguish from rheumatoid arthritis, but fewer people have residual deformities.

3. Extra-articular manifestations

The extra-articular lesions of AS mostly appear after spondylitis, and occasionally extra-articular symptoms occur months or years before musculoskeletal symptoms. AS can invade multiple systems throughout the body and be associated with a variety of diseases.

(1) Aortic valve disease is the most common heart disease. Clinically, about 1% of patients have varying degrees of aortic regurgitation; about 8% develop heart block, which may exist simultaneously with aortic regurgitation or occur alone. In severe cases, complete atrioventricular block may lead to Adams-Stokes syndrome. When the lesion involves the coronary artery ostia, angina pectoris may occur. Aortic myoma, pericarditis and myocarditis occur in a few cases.

(2) Long-term follow-up of ocular lesions showed that 25% of AS patients had conjunctivitis, iritis, uveitis or uveitis, the latter of which may occasionally be complicated by spontaneous anterior chamber hemorrhage. Iritis is prone to relapse, and the longer the illness lasts, the higher the incidence rate, but it has nothing to do with the severity of spondylitis. It is common in patients with peripheral joint disease, and in a few cases it may occur before spondylitis. Eye diseases are often self-limited and sometimes require treatment with corticosteroids. Some of them can cause glaucoma or blindness if not properly treated.

(3) In AS patients with chronic otitis media, extra-articular manifestations are significantly more common than those in AS patients without chronic otitis media.

(4) Pulmonary lesions: A small number of AS patients may develop irregular spotted fibrosis in the upper lobes in the later stages of the disease, which manifests as expectoration, wheezing, and even hemoptysis, and may be accompanied by recurrent pneumonia or pleurisy.

(5) Neurological diseases due to spinal ankylosing and osteoporosis can easily lead to cervical dislocation and spinal fractures, thus causing spinal cord compression. If disc inflammation occurs, it will cause severe pain. In the later stages of AS, the cauda equina may be invaded, resulting in cauda equina syndrome, which can lead to radicular pain in the lower limbs or buttocks, loss of sensation in the sacral nerve distribution area, weakened Achilles tendon reflexes, and motor dysfunction such as bladder and rectum.

(6) Amyloidosis is a rare complication of AS.

(7) Renal and prostate lesions Compared with RA, AS rarely causes renal damage, but there are reports of IgA nephropathy. The incidence of chronic prostatitis in AS is higher than that in the control group, but its significance is unclear.