Rheumatoid Arthritis Diagnosis
Getting an accurate diagnosis is the first step towards managing rheumatoid arthritis effectively. Early detection and treatment can prevent or delay complications such as permanent damage to the joints and disability. Diagnosing rheumatoid arthritis in its early stages can be a challenge because its early signs and symptoms also present in other health problems. The findings that are more likely to suggest the diagnosis of rheumatoid arthritis include:
- morning stiffness in and around the joints that lasts for 1 hour
- involvement of three or more joints at the same time
- symmetric involvement of joints
- presence of subcutaneous nodules
- abnormal amounts of serum rheumatoid factor
- radiographic images suggestive of erosions and bony decalcification localized in adjacent to the affected joints.
Rheumatoid arthritis is diagnosed based on medical history, physical examination, blood tests, and imaging procedures. You might first discuss your symptoms with a family physician, then you may be referred to a rheumatologist for further evaluation and management.
Medical history. The doctor obtains a detailed medical history by asking questions pertaining to the health problems you've had, as well as diseases that have been affecting parents or siblings. The doctor will also ask you to describe the symptoms that you have been experiencing, when they usually occur, and if anything relieves them or makes them worse.
Physical examination.During the physical exam, the doctor checks the joints for swelling, redness and warmth. The patient's muscle strength, skin, and reflexes will also be assessed.
Laboratory tests. If health history and physical examination results are suggestive of rheumatoid arthritis, the doctor may consider further testing to help identify what has been causing the signs and symptoms. Below are the blood tests that are used for diagnosing RA:
Erythrocyte sedimentation rate (ESR) The ESR or sed rate test helps in diagnosing conditions associated with inflammation, including infections, some cancers, and autoimmune diseases. This test measures the speed at which red blood cells sink to the bottom of a test tube within a 1-hour period. If the blood has abnormal proteins due to inflammation or infection, the red blood cells clump together, and this causes them to fall at a faster rate. ESR is considered as nonspecific because increases alone do not tell the doctor exactly where the inflammation is or what has been causing it. Moreover, high sedimentation rate may occur as a result of other conditions other than inflammation. For this reason, ESR is usually done in conjunction with other tests.
Rheumatoid factor.The rheumatoid factor (RF) test helps diagnose rheumatoid arthritis (RA), it is also used to distinguish the disease from other forms of arthritis and other conditions that cause similar symptoms of joint pain, inflammation, and stiffness. Rheumatoid factor is an antibody produced by the immune system. Significant concentrations of RF is suggestive of RA. A positive RF test may also help predict the potential severity of rheumatoid arthritis and the complications that it may cause.
Anti-cyclic citrullinated peptide (Anti-CCP) antibodies. This is one of the most specific blood tests to help diagnose RA. Moderate to high levels of anti-CCP in the blood confirm the diagnosis of rheumatoid arthritis. In addition, high anti CCP readings also indicate a more severe course of rheumatoid arthritis.
Complete blood count. This test measures the levels of red blood cells, white blood cells, and platelets. Complete blood count is ordered to help diagnose rheumatoid arthritis, and for monitoring its progression and treatment. This test helps identify the type of inflammation present.
C-reactive protein. CRP is produced by the liver when there is infection or inflammation. The CRP test is ordered to help evaluate autoimmune disease like rheumatoid arthritis and lupus It is often repeated to determine whether treatment is effective. CRP test is helpful in evaluating health conditions associated with inflammation because the CRP levels fall as inflammation subsides.
X-rays. This imaging procedure is useful in predicting outcome, assessing the severity of joint damage, and determining whether surgery is needed. In the early stages of rheumatoid arthritis, there may not be any changes in the radiographic images, or it may show some tissue swelling or joint effusion. Over time, abnormalities continue to appear on the x-ray. Characteristic x-ray findings in patients with RA include:
- soft tissue swelling.
- juxta-articular osteopenia. Osteopenia is a condition characterizes by lower than normal where bone mineral density. In rheumatoid arthritis, this may result from inflammation of adjacent joints.
- loss of articular cartilage with decreasing bone spaces.
- bony erosions- this may indicate an increased risk for future erosions articular damage, and the need more aggressive treatments
Magnetic Resonance Imaging(MRI). MRI may detect erosions much earlier than conventional methods. In addition, this test gives more detailed images of articular and periarticular structures. An MRI might be useful in rheumatoid patients whose x-rays show no changes. If erosions show on MRI, more aggressive treatments may be considered instead of using milder drugs.
Ultrasonography. Ultrasound imaging has become a more widely used procedure for assessing rheumatoid arthritis. It can detect bony erosions in RA patients with greater sensitivity than conventional radiography. Ultrasound images are comparable to that of the MRI. In addition, ultrasound accurately detects synovial fluid and thickened synovial tissue.
Rheumatoid Arthritis: Early Diagnosis and Treatment John J. Cush, Michael E. Weinblatt, Arthur Kavanaugh