Diagnosis of rheumatoid arthritis
It can be difficult to definitively diagnose rheumatoid arthritis (RA) in the early phase of an inflammatory arthritis—see Acute polyarthritis in adults for an approach to the assessment of new-onset polyarthritis. Prompt diagnosis is important to avoid delays in initiating disease-modifying antirheumatic drugs (DMARDs) to prevent irreversible joint damage. Refer any patient with suspected RA promptly to a specialist, especially those with indicators of a poor prognosis—see Key indicators of a poor prognosis for people with rheumatoid arthritis for the key indicators of a poor prognosis for patients with RA.
Rheumatologists often have fast-track triage systems for patients with suspected RA and strongly encourage direct contact by general practitioners to expedite referral or to obtain advice on treatment (eg before starting oral corticosteroids). The appropriate time frame for referral is further influenced by the results of specific investigations.
The diagnosis of RA is largely clinical. The clinical diagnosis may be supported by results of specific investigations for RA, if there is evidence of autoantibodies and systemic inflammation.