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Several connective tissue diseases, including the spondyloarthropathies (also called spondyloarthritides), cause prominent joint inflammation. The spondyloarthropathies affect the joints and spine. These disorders share certain characteristics. For example, they may cause back pain, inflammation of the eye (uveitis), digestive symptoms, and rashes. Some are strongly associated with the HLA-B27 gene. Because they cause many of the same problems and share genetic characteristics, some experts think these disorders share similar causes and ways of causing symptoms. The spondyloarthropathies cause joint inflammation, similar to rheumatoid arthritis. However, in contrast to rheumatoid arthritis, rheumatoid factor (see Joint Disorders: Diagnosis) is negative in the spondyloarthropathies (hence, they are also called the seronegative spondyloarthropathies). Among the spondyloarthropathies are psoriatic arthritis, reactive arthritis, and ankylosing spondylitis.
Psoriatic Arthritis
Psoriatic arthritis is a form of joint inflammation that occurs in some people who have psoriasis of the skin or nails.
The disease resembles rheumatoid arthritis but does not produce the antibodies characteristic of rheumatoid arthritis. Psoriatic arthritis occurs in about 5 to 40% of people with psoriasis (a skin condition causing flare-ups of red, scaly rashes and thickened, pitted nails—see Itching and Noninfectious Rashes: Psoriasis). The cause of psoriatic arthritis is unknown.
Symptoms and Diagnosis
Inflammation often affects joints closest to the tips of the fingers and toes, although other joints, including the hips, knees and spine, are often affected as well. Often the joints of the upper extremities are affected more. Back pain may be present. The joints may become swollen and deformed when inflammation is chronic. Psoriatic arthritis often involves joints less symmetrically than rheumatoid arthritis and involves fewer joints. The psoriasis rash may appear before or after arthritis develops. Sometimes the rash is not noticed because it is hidden in the scalp or creases of the skin such as between the back of the buttocks and thigh. The skin and joint symptoms sometimes appear and disappear together.
The diagnosis is made by identifying the characteristic joint inflammation in a person who has arthritis and psoriasis or a family history of psoriasis. There are no tests to confirm the diagnosis, but x-rays help show the extent of joint damage.
Prognosis and Treatment
The prognosis for psoriatic arthritis is usually better than that for rheumatoid arthritis because fewer joints are affected. Nonetheless, the joints can be severely damaged.
Treatment is aimed at controlling the skin rash and relieving the joint inflammation. Several drugs that are effective in treating rheumatoid arthritis are also used to treat psoriatic arthritis, particularly nonsteroidal anti-inflammatory drugs (NSAIDs), methotrexate, cyclosporine, and tumor necrosis factor (TNF) inhibitors.
Some people take methoxsalen (psoralen) by mouth and undergo psoralen plus ultraviolet A light treatments. This combination relieves the skin symptoms and most of the joint inflammation but may not help inflammation of the spine.
Reactive Arthritis
Reactive arthritis (sometimes called Reiter syndrome) is inflammation of the joints and tendon attachments at the joints, often related to an infection.
Reactive arthritis is so called because the joint inflammation seems to be a reaction to an infection originating in the gastrointestinal or genitourinary tract.
There are two forms of reactive arthritis. One form seems to occur with sexually transmitted diseases, such as a chlamydial infection, and occurs most often in men aged 20 to 40. The other form usually follows an intestinal infection such as shigellosis, salmonellosis, or a Campylobacter infection. Most people who have these infections do not develop reactive arthritis. People who develop reactive arthritis after exposure to these infections seem to have a genetic predisposition to this type of reaction, related in part to the same gene found in people who have ankylosing spondylitis (see Joint Disorders: Ankylosing Spondylitis). There is some evidence that the chlamydia bacteria and possibly other bacteria actually spread to the joints, but the roles of the infection and the immune reaction to it are not clear.
Reactive arthritis may be accompanied by inflammation of the conjunctiva (see Conjunctival and Scleral Disorders: Overview of Conjunctival and Scleral Disorders) and the mucous membranes (such as those of the mouth and genitals) and by a distinctive rash. This form of reactive arthritis previously was called Reiter syndrome.
Symptoms
Joint pain and inflammation may be mild or severe. Several joints are usually affected at once—especially the knees, toe joints, and areas where tendons are attached to bones, such as at the heels. Often, the large joints of the lower limbs are affected the most. Reactive arthritis often involves joints less symmetrically than rheumatoid arthritis. Tendons may be inflamed and painful. Back pain may occur, usually when the disease is severe.
Inflammation of the urethra (the channel that carries urine from the bladder to the outside of the body) can develop, usually about 7 to 14 days after the infection. In men, inflammation of the urethra causes moderate pain and a discharge from the penis or a rash on the glans of the penis (balanitis circinata). The prostate gland may be inflamed and painful. The genital and urinary symptoms in women, if any occur, are usually mild, consisting of a slight vaginal discharge or uncomfortable urination. Other symptoms include a low-grade fever and excessive tiredness (fatigue).
The conjunctiva (the membrane that lines the eyelid and covers the eyeball) can become red and inflamed, causing itching or burning, sensitivity to light, and excessive tearing. Small and usually painless or sometimes tender sores can develop in the mouth. Occasionally, a distinctive rash of hard, thickened spots may develop on the skin, especially of the palms and soles (keratoderma blennorrhagicum). Yellow deposits may develop under the fingernails and toenails.
Rarely, heart and blood vessel complications (such as inflammation of the aorta), inflammation of the membranes covering the lungs, dysfunction of the aortic valve, and brain and spinal cord symptoms or peripheral nervous system (which includes all the nerves outside the brain and spinal cord) symptoms may develop.
In most people, the initial symptoms disappear in 3 or 4 months, but up to 50% of people experience recurring joint inflammation or other symptoms over several years. Joint and spinal deformities may develop if the symptoms persist or recur frequently. Some people who have reactive arthritis become permanently disabled.
Diagnosis
The combination of joint symptoms and a preceding infection, particularly if there are genital, urinary, skin, and eye symptoms, leads a doctor to suspect reactive arthritis. Because these symptoms may not appear simultaneously, the disease may not be diagnosed for several months. No simple laboratory tests are available to confirm the diagnosis, but x-rays are often performed to assess the status of joints. Tests may be done to exclude other disorders that can cause similar symptoms.
Treatment
When the disease affects the genitals or urinary tract, antibiotics are given to treat the infection, but treatment is not always successful and its optimal duration is not known.
Joint inflammation is usually treated with an NSAID. Sulfasalazine or drugs that suppress the immune system (such as azathioprine or methotrexate) may be used, as in rheumatoid arthritis. Physical therapy is helpful in maintaining joint mobility during the recovery phase.
Conjunctivitis and skin sores do not usually need to be treated, although severe eye inflammation (uveitis) may require corticosteroid and dilating eyedrops.
Ankylosing Spondylitis
Ankylosing spondylitis is a disorder characterized by inflammation of the spine and large joints, resulting in stiffness and pain.
The disease is 3 times more common among men than women, developing most commonly between the ages of 20 and 40. Its cause is not known, but the disease tends to run in families, indicating that genetics plays a role. Ankylosing spondylitis is 10 to 20 times more common among people whose parents or siblings have it.
Symptoms
Mild to moderate flare-ups of inflammation generally alternate with periods of almost no symptoms.
The most common symptom is back pain, which varies in intensity from one episode to another and from one person to another. Pain is often worse at night and in the morning. Early morning stiffness that is relieved by activity is also very common. Pain in the lower back and the associated muscle spasms are often relieved by bending forward. Therefore, people often assume a stooped posture, which can lead to a permanent bent-over position. In others, the spine becomes noticeably straight and stiff.
Loss of appetite, low-grade fever, weight loss, excessive tiredness (fatigue), and anemia can accompany the back pain. If the joints connecting the ribs to the spine are inflamed, the pain may limit the ability to expand the chest to take a deep breath. Stiffness (fusion) of the spine can restrict the ability to expand the chest wall as well. Occasionally, pain starts in large joints, such as the hips, knees, and shoulders.
One third of the people have recurring attacks of mild eye inflammation (uveitis), which usually does not impair vision if treated promptly. In a few people, inflammation of a heart valve results in a permanently damaged valve or other problems can affect the heart or aorta. If damaged vertebrae press against nerves or the spinal cord, numbness, weakness, or pain can develop in the area supplied by the affected nerves. Cauda equina (horse's tail) syndrome is an occasional complication (see Spinal Cord Disorders: What Is the Cauda Equina Syndrome? ). Achilles tendinitis can develop.
Diagnosis
The diagnosis is based on the pattern of symptoms and on x-rays of the spine and affected joints, which show a wearing away (erosion) of the joint between the spine and the hip bone (sacroiliac joint) and the formation of bony bridges between the vertebrae, making the spine stiff. The erythrocyte sedimentation rate (ESR), a test that measures the rate at which red blood cells settle to the bottom of a test tube containing blood, tends to be high, indicating inflammation.
Prognosis
Most people develop some disabilities but can still lead normal, productive lives. In some people, the disease is more progressive, causing severe deformities. The prognosis is discouraging for people who develop extreme stiffness of the spine.
Treatment
Treatment focuses on relieving back and joint pain, maintaining range of motion in the joints, preventing damage in other organs, and preventing or correcting spinal deformities. NSAIDs can reduce the pain and inflammation, thus enabling people to do important exercises to retain posture, including stretching and deep breathing. Sulfasalazine or methotrexate may help the pain in joints other than those of the back. The TNF inhibitors etanercept, adalimumab, or infliximab can relieve back pain and inflammation.
Corticosteroid eye drops may help in the short-term treatment of inflammation of the eyes, and an occasional corticosteroid injection may be helpful for 1 or 2 joints other than the spine. Muscle relaxants and opioid analgesics are occasionally used, but for only brief periods to relieve severe pain and muscle spasms. If hips or knees become eroded or fixed in a bent position, surgical treatment to replace the joint can relieve pain and restore function.
The long-range goals of treatment are to maintain proper posture and develop strong back muscles. Daily exercises strengthen the muscles that oppose the tendency to bend and stoop. It has been suggested that people spend some time each day—often while reading—lying on their stomach propped up on their elbows because this position extends the back and helps to keep the back flexible. Because chest wall motion can be restricted, which impairs lung function, cigarette smoking, which also impairs lung function, is strongly discouraged.
Other Spondyloarthropathies
Spondyloarthropathy can develop in association with digestive conditions (sometimes called enteropathic arthritis), such as inflammatory bowel disease, intestinal bypass surgery, or Whipple's disease. Juvenile-onset spondyloarthropathy affects the lower extremities, often affects joints on opposite sides of the body to different degrees, and begins most commonly in boys aged 7 to 16. Spondyloarthropathy can also develop in people with no characteristics of other specific spondyloarthropathy (undifferentiated spondyloarthropathy). Treatment of the arthritis of these other spondyloarthropathies is similar to that of treatment of reactive arthritis (see Joint Disorders: Reactive Arthritis).
Last full review/revision February 2008 by Roy D. Altman, MD
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