What are the recommended initial investigations for a patient presenti

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

For a patient presenting with joint pain and swelling, the recommended initial investigations include:

Clinical examination to identify synovitis and affected joints, especially small joints of hands or feet, which may indicate rheumatoid arthritis (RA) .
Blood tests such as rheumatoid factor (RF) in adults with suspected RA who have synovitis on examination .
Anti-cyclic citrullinated peptide (anti-CCP) antibodies measurement if rheumatoid factor is negative but RA is still suspected .
X-rays of hands and feet to detect erosions or persistent synovitis in suspected RA .
Serum urate level measurement if gout is suspected, especially with rapid onset of severe joint pain and swelling, to confirm diagnosis (serum urate ≥360 micromol/litre) .
Consider joint aspiration and synovial fluid microscopy if gout diagnosis remains uncertain or to exclude septic arthritis .
Imaging (X-ray, ultrasound, or dual-energy CT) may be considered if joint aspiration is not possible or diagnosis remains unclear .
For osteoarthritis, diagnosis is primarily clinical without routine imaging unless atypical features or alternative diagnoses are suspected .

Referral to a specialist should not be delayed by investigations if persistent synovitis of undetermined cause is present .

What are the recommended initial investigations for a patient presenting with joint pain and swelling?