oPatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.
Acute polyarthritis has a very wide differential diagnosis, presenting significant diagnostic difficulties. Where oligoarthritis (<5 joints affected) is the presenting feature, some of the causes of acute monoarthritis must be considered, of which the most important not to miss is septic arthritis (particularly that due to gonococcal infection which may affect several joints).
This article also considers conditions which may cause polyarthralgia which can present in a similar fashion to the inflammatory diseases.
Careful clinical assessment should give a reasonable differential diagnosis which can be further narrowed down by appropriate investigations. Autoantibody tests used to aid diagnosis of rheumatological conditions can be misleading if not considered in the context of the clinical presentation. They are best used to confirm a clinical suspicion, rather than as suggesters of a diagnosis.
Conditions more commonly considered to be chronic and indolent can present floridly in the acute phase. It can take time for a disease to evolve into its classical pattern and to decide whether it is a chronic or one-off phenomenon. In some cases a definitive diagnosis may never be reached.
See also the separate articles on Aching Joints - Assessment, Investigations and Management in Primary Care and Rheumatological History, Examination and Investigations.
- Demographic details such as age, sex, ethnic origin and occupation can give useful diagnostic clues. For example, juvenile chronic arthritis is the most common arthritis in children.
- Family history may be present in cases of rheumatoid arthritis (RA), seronegative arthropathies and osteoarthritis.
- Pain is not often discriminatory in diagnostic terms. Speed of onset may help - gout tends to come on abruptly, whereas RA is usually more gradual. Similarly, gout tends to cause very severe, excruciating pain.
- Diurnal variation of symptoms may give useful clues. An inflammatory arthritis tends to be worse on waking and eases as the day goes on. Mechanical pain tends to have the opposite effect.
- Ask about morning stiffness and joint swelling.
- Migratory arthritis (flitting from joint to joint over a period of days) might suggest gonococcal infection, rheumatic fever (RF), sarcoidosis, systemic lupus erythematosus (SLE), Lyme disease or bacterial endocarditis.
- Pattern of joint involvement is very useful in suggesting a diagnosis. For example:
- Osteoarthritis of the hand affects the distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints but spares the metacarpophalangeal (MCP) joints.
- RA affects the MCP and PIP joints but spares the DIP joints.
- Psoriatic arthritis, crystal arthropathies and sarcoidosis can affect all these joints.
- Large weight-bearing joints and facet joints of the spine are often affected by osteoarthritis.
- Axial involvement in younger patients suggests a seronegative arthropathy such as ankylosing spondylitis or inflammatory bowel disease-associated arthropathy.
- Symmetrical joint involvement tends to occur in systemic syndromes such as RA, SLE, viral arthritis and drug/serum sickness reactions.
- In asymmetrical joint involvement consider gout, psoriatic arthritis, and reactive arthritis.
- Extra-articular symptoms should be asked about and can aid diagnosis. The eyes, parotid glands, skin, mouth, genitals and muscles can all be affected by rheumatological diagnoses.
- Take a full drug history - some drugs (eg, hydralazine, procainamide, quinidine and minocycline) can cause a lupus-like syndrome and there have been reports of a variety of drugs associated with polyarthralgia (eg, moxifloxacin).
- Systemic symptoms should also be sought - eg, fever and weight loss.
- Are there any other associated presenting symptoms - eg, abdominal or respiratory disease?
- Check temperature.
- Nail changes (eg, pitting) may suggest psoriatic arthropathy.
- Look at eyes for signs of inflammation.
- Check major lymph nodes for evidence of lymphadenopathy.
- Check skin for rashes (eg, psoriasis, SLE) and evidence of vasculitis. Feel extensor aspects of forearms for nodules. Check shins for evidence of erythema nodosum.
- Cardiac examination - listen for murmurs if there is reason to suspect RF.
- Abdominal examination - may reveal evidence of hepatomegaly and/or splenomegaly.
- Examine other systems as indicated by the history and clinical hypotheses.
- Joint examination:
- Look for signs of inflammation in the joint, such as heat, tenderness and synovial thickening.
- Establish whether there are symmetrical or asymmetrical joints involved.
- Active and passive movements of affected joints and the degree of pain and/or crepitus may also be helpful. However, crepitus and pain will not differentiate between inflammatory and non-inflammatory causes of joint pain. They may, however, give some indication as to the degree of damage.
- Also examine the structures around the joint and determine if the symptoms are intra-articular or periarticular.
|Discriminating features of common causes of polyarthritis|
Development over time
Pattern joint involvement
Extra-articular manifestations/other features
|Chronic||Yes||Small and large joints||Yes||Neck||Nodules|
|Chronic||No||Weight-bearing joints, proximal interphalangeal joint, distal interphalangeal joint, 1st carpometacarpal joint||Variable||Neck and lower back||None, Heberden's nodes (distal) and Bouchard's nodes (proximal)|
Systemic lupus erythematosus
|Chronic||Yes||Small joints||Yes||No||Malar rash, mouth ulcers, pleuritis, pericarditis|
|Chronic||Yes||Large and small joints||Variable||Variable||Psoriatic rash, dactylitis, nail changes, tendonitis|
Human parvovirus B19 infection
|Acute and remitting||Yes||Small joints||Yes||No||Lacy rash, malar rash|
|Chronic||Yes||Large joints||Yes||Yes||Iritis, aortic regurgitation, tendonitis|
The diagnoses below are not exhaustive but cover the vast majority of causes of polyarthritis.
|Viral infections ||Direct bacterial infections |
|Other infections ||Reactive to bacterial infection |
|Crystal arthropathy/metabolic disease ||Systemic rheumatological disease|
|Systemic vasculitic disease ||Spondyloarthropathies|
|Endocrine disease ||Malignancy|
Where there is any suspicion of septic arthritis, immediate aspiration of synovial fluid should be carried out. Synovial fluid analysis may play a role in diagnosis of crystal arthropathies and inflammatory conditions but results need to be carefully interpreted in context. See the separate article on Acute Monoarthritis for a table of synovial fluid findings in the more common causes of joint inflammation.
- Urinalysis - indicates any renal involvement.
- Blood tests - FBC, ESR, CRP and U&E are useful screening investigations which give diagnostic clues.
- Autoantibodies - can help to confirm a diagnosis but are often relatively nonspecific or insensitive. They should be interpreted in the context of the clinical presentation, preferably with specialist rheumatological input for the less common markers.
- Radiology - X-rays play a variable role in their contribution to diagnosis but are a useful first-line investigation. Other imaging modalities may need to be conducted with rheumatological/radiological advice.
- Joint aspiration is helpful in the differential diagnosis of arthritis and is the definitive method for diagnosis of septic arthritis and crystal arthritis.
Directed at the underlying diagnosis. See the links to the individual diagnoses for detail.
Symptomatic treatment of inflammatory conditions with non-steroidal anti-inflammatory drugs should be considered whilst awaiting the evolution of an arthritis, where there are no contra-indications or significant drug interactions.
Where there is a significant inflammatory illness as revealed by clinical severity and CRP/ESR, etc, early advice for disease-modifying interventions can significantly reduce joint pathology in some conditions.
If in doubt, seek advice on the appropriate course.
Further reading & references
- Rheumatoid arthritis: the management of rheumatoid arthritis in adults; NICE Clinical Guideline (February 2009)
- Management of early rheumatoid arthritis; Scottish Intercollegiate Guidelines Network - SIGN (February 2011)
- Osteoarthritis; NICE Clinical Guideline (January 2008)
- Lane SK, Gravel JW Jr; Clinical utility of common serum rheumatologic tests. Am Fam Physician. 2002 Mar 15;65(6):1073-80.
- Mies Richie A, Francis ML; Diagnostic approach to polyarticular joint pain. Am Fam Physician. 2003 Sep 15;68(6):1151-60.
- Dalle Vedove C, Simon JC, Girolomoni G; Drug-induced lupus erythematosus with emphasis on skin manifestations and the role of anti-TNFalpha agents. J Dtsch Dermatol Ges. 2012 Dec;10(12):889-97. doi: 10.1111/j.1610-0387.2012.08000.x. Epub 2012 Sep 3.
- Torres JR, Bajares A; Severe acute polyarthritis in a child after high doses of moxifloxacin. Scand J Infect Dis. 2008;40(6-7):582-4.
- Samanta J, Kendall J, Samanta A; Polyarthralgia. BMJ. 2003 Apr 19;326(7394):859.
- Serratrice J, Disdier P, Colson P, et al; Acute polyarthritis revealing hepatitis E. Clin Rheumatol. 2007 Nov;26(11):1973-5. Epub 2007 Mar 6.
- Courtney P, Doherty M; Joint aspiration and injection and synovial fluid analysis. Best Pract Res Clin Rheumatol. 2013 Apr;27(2):137-69. doi: 10.1016/j.berh.2013.02.005.
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Gurvinder Rull
Dr Colin Tidy
Dr John Cox