Synopsis
Convert a multi-joint complaint into a timed, anatomical and systemic phenotype, identify infection or organ-threatening disease, and refer persistent inflammatory arthritis before avoidable structural damage occurs.
- Oligoarthritis involves a small number of joints and polyarthritis a broader multi-joint pattern, but count swollen joints rather than relying on the patient's word 'all over'.
- Define onset, duration, symmetry, small- versus large-joint distribution, axial disease, enthesitis, dactylitis and whether inflammation is additive, migratory or episodic.
- Examine skin, scalp, nails, eyes, mouth, lymph nodes and relevant cardiopulmonary, abdominal and neurological systems because extra-articular findings often decide the differential.
- Persistent synovitis warrants rheumatology referral even with normal CRP, negative rheumatoid factor and normal early radiographs.
- A very hot single joint, bacteraemia risk or systemic toxicity cannot be explained away by an otherwise convincing polyarthritis pattern; aspirate the suspicious joint.
- Use infection and travel history to select tests for parvovirus, hepatitis, HIV or sexually transmitted infection; indiscriminate viral panels create false leads.
- ANA is not a screening test for nonspecific joint pain, and a positive result without compatible systemic features may not represent connective-tissue disease.
- Document functional loss, work, pregnancy plans, vaccination and infection risk early because these shape treatment urgency and safe DMARD choice.
Key red flags
Fever, rash, exposure, immunosuppression, endocarditis risk or one destructive joint among several painful joints raises infection and requires urgent cultures and sampling.
Investigation priorities
Confirm synovitis, define distribution and find disease-defining extra-articular features.
Management branches
Polyarthritis with fever, shock, focal hot joint, renal change, visual symptoms, neuropathy or cardiopulmonary involvement.
- Stabilise physiology, obtain blood cultures and organ-directed tests, and aspirate any disproportionately inflamed accessible joint before antimicrobial treatment when safely possible.
- Contact the appropriate acute specialty and rheumatology; begin sepsis or organ-protection treatment according to the responsible pathway rather than awaiting a complete antibody panel.
- Trend physiology and organ function while microbiology and targeted immune tests return, revising the diagnosis when response or distribution is discordant.