Rheumatoid Arthritis Diagnosis

A primary care physician may suspect RA based in part on a person's signs and symptoms. If so, the patient will be referred to a rheumatologist – a specialist with specific training and skills to diagnose and treat RA. In its early stages, RA may resemble other forms of inflammatory arthritis. No single test can confirm RA. To make a proper diagnosis, the rheumatologist will ask questions about personal and family medical history, perform a physical exam and order diagnostic tests.

Medical History

The doctor will ask about personal and family medical history as well as recent and current symptoms (pain, tenderness, stiffness, difficulty moving).

Physical Exam

The doctor will examine each joint, looking for tenderness, swelling, warmth and painful or limited movement. The number and pattern of joints affected can also indicate RA. For example, RA tends to affect joints on both sides of the body. The physical exam may reveal other signs, such as rheumatoid nodules or a low-grade fever.

Blood Tests

The blood tests will measure inflammation levels and look for biomarkers such as antibodies (blood proteins) linked with RA.

Inflammation

Erythrocyte sedimentation rate (ESR, or “sed rate”) and C-reactive protein (CRP) level are markers of inflammation. A high ESR or CRP is not specific to RA, but when combined with other clues, such as antibodies, helps make the RA diagnosis.

Antibodies

Rheumatoid factor (RF) is an antibody found in about 80 percent of people with RA during the course of their disease. Because RF can occur in other inflammatory diseases, it’s not a sure sign of having RA. But a different antibody – anti-cyclic citrullinated peptide (anti-CCP) – occurs primarily in patients with RA. That makes a positive anti-CCP test a stronger clue to RA. But anti-CCP antibodies are found in only 60 to 70 percent of people with RA and can exist even before symptoms start.

Imaging Tests

An X-ray, ultrasound or magnetic resonance imaging scan may be done to look for joint damage, such as erosions – a loss of bone within the joint – and narrowing of joint space. But if the imaging tests don’t show joint damage that doesn’t rule out RA. It may mean that the disease is in an early stage and hasn’t yet damaged the joints.

RA can be hard to detect because it may begin with subtle symptoms, such as achy joints or a little stiffness in the morning. Also, many diseases behave like RA early on. For this reason, if you or your primary care physician thinks you have RA, you should see a rheumatologist. A rheumatologist is a physician with the skill and knowledge to reach a correct diagnosis of RA and to make the most suitable treatment plan.

Diagnosis of RA depends on the symptoms and results of a physical exam, such as warmth, swelling and pain in the joints. Some blood tests also can help confirm RA. Telltale signs include:

• Anemia (a low red blood cell count)
• Rheumatoid factor (an antibody, or blood protein, found in about 80 percent of patients with RA in time, but in as few as 30 percent at the start of arthritis)
• Antibodies to cyclic citrullinated peptides (pieces of proteins), or anti-CCP for short (found in 60–70 percent of patients with RA)
• Elevated erythrocyte sedimentation rate (a blood test that, in most patients with RA, confirms the amount of inflammation in the joints)

X-rays can help in detecting RA, but may not show anything abnormal in early arthritis. Even so, these first X-rays may be useful later to show if the disease is progressing. Often, MRI and ultrasound scanning are done to help judge the severity of RA.

There is no single test that confirms an RA diagnosis for most patients with this disease. (This is above all true for patients who have had symptoms fewer than six months.) Rather, a doctor makes the diagnosis by looking at the symptoms and results from the physical exam, lab tests and X-rays.

- See more at: http://www.rheumatology.org/I-Am-A/Patient-Caregiver/Diseases-Conditions/Rheumatoid-Arthritis#sthash.6pVrwxgq.dpuf