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The diagnostic "work-up" of patients with suspected rheumatoid arthritis (RA) usually involves the following evaluations:

• Patient history and physical examination
• Laboratory studies
• Imaging studies

Patient History and Physical Examination

Because rheumatoid arthritis (RA) is primarily a clinical diagnosis, the patient history and physical examination are critical for establishing an accurate diagnosis. The patient history focuses of the following areas:

• Chief complaint - What prompted the patient to visit the health care provider at this time?

• Signs and symptoms as described by the patient particularly joint pain, swelling, tenderness, morning stiffness, and fatigue.

• How long have the symptoms been present?

• Severity of the symptoms (mild, moderate, or severe)

• Any medications that the patient may be taking to alleviate the symptoms

• Is the patient experiencing any functional limitations as a result of the symptoms?

The physical examination of patients with suspected RA focuses on the following areas:

• Examination of the hands (wrists, PIP joints, MCP joints)
• Examination of other joints (elbows, knees, ankles, MTP joints)
• Is there any evidence of symmetrical arthritis (arthritis affecting the same joints simultaneously on the left and right sides of the body)?
• Is there any evidence of rheumatoid nodules (bumps beneath the surface of the skin)?

Laboratory Studies

Although the diagnosis of rheumatoid arthritis (RA) is based primarily upon the patient history and physical examination, certain blood tests may be useful for supporting the diagnosis. The American Academy of Rheumatology recommends the following baseline laboratory studies for patients with RA:

• Rheumatoid factor - Approximately 75% of patients with RA test positive for rheumatoid factor (RF) - an autoantibody that is thought to play an important role in precipitating the chronic inflammation that causes RA. Rheumatoid factor is also used as a prognostic marker for RA to predict the severity and progression of the disease. In general, patients with RA who test positive for the RF autoantibody have a more advanced form of the disease than patients with RA who test negative for the RF autoantibody. It is important to note, however, that the RF test is not specific for RA because:

  • RF may be elevated in certain conditions other than RA
  • approximately 25% of patients with RA test negative for RF
  • approximately 5% of people with RA test positive for RF

• In rheumatoid factor negative patients with features suggesting RA, testing for antibody against cyclic citrulinated proteins (anti-CCP antibodies) may be helpful.

• Erythrocyte sedimentation rate (ESR)- The ESR is a test used as a marker for inflammation in general and is, therefore, not a specific test for RA. Typically, however, patients with RA will have an elevated ESR.

• C-reactive protein (CRP)- The CRP is another marker that is used to measure inflammation in the body and is, therefore, not specific for RA. Patients with severe RA, however, will usually have elevated levels of CRP in the bloodstream.

• Complete blood count (CBC) - Patients with early stage RA typically have a normal or slightlly elevated white blood cell (WBC) count but the number of platelets in the bloodstream is usually elevated.

Imaging Studies