How should I differentiate between osteoarthritis and rheumatoid arthritis in a primary care setting?

To differentiate between osteoarthritis (OA) and rheumatoid arthritis (RA) in primary care:

• Osteoarthritis is typically diagnosed clinically in people aged 45 or over who have activity-related joint pain and either no morning stiffness or morning stiffness lasting no longer than 30 minutes. Imaging is not routinely required unless atypical features or alternative diagnoses are suspected ².
• Rheumatoid arthritis should be suspected in adults with persistent synovitis, especially if multiple small joints of the hands or feet are affected, or if symptoms have persisted for 3 months or longer before seeking advice. Referral for specialist opinion is recommended in these cases ¹.
• Blood tests such as rheumatoid factor and anti-cyclic citrullinated peptide (anti-CCP) antibodies can support the diagnosis of RA but should not delay referral ¹.
• X-rays of hands and feet may be used in suspected RA to detect erosions but are not routinely used to diagnose OA ¹,².
• OA symptoms are generally related to mechanical use and improve with rest, whereas RA symptoms often include prolonged morning stiffness and symmetrical joint involvement with systemic features ¹,².