Multiple Joint Pain
Differential Diagnosis
Common Diagnoses
- Rheumatoid Arthritis (RA)
- Psoriatic Arthropathy
- Viral Polyarthritis (e.g. Hepatitis, Rubella)
- Connective Tissue Diseases (e.g. SLE, Systemic Sclerosis, Polyarteritis Nodosa, Giant Cell Arteritis)
- Multiple Osteoarthritis (OA)
Occasional Diagnoses
- The Spondoarthritides: Ankylosing Spondylitis, Reiter’s Disease, Enteropathic Arthritis, behçet’s Syndrome, Juvenile Chronic Arthritis
- Malignancy (Usually Secondary)
- Iatrogenic: Corticosteroid Therapy, Isoniazid, Hydralazine
- Hypertrophic Pulmonary Osteoarthropathy (Due to Lung Cancer)
- Sarcoidosis
Rare Diagnoses
- Sickle-Cell Crisis
- Amyloidosis
- Rheumatic Fever
- Atypical Systemic Infections (e.g. Lyme Disease, Weil’s Disease, Brucellosis, Syphilis [Secondary])
- Decompression Sickness (the Bends)
Ready Reckoner
Key distinguishing features of the most common diagnoses
| RA | Psoriasis | Viral | Connective Tissue | OA | |
|---|---|---|---|---|---|
| Symmetrical | Yes | Possible | Possible | Possible | Possible |
| Rash | No | Yes | Possible | Possible | No |
| Fever, Malaise | Possible | No | Yes | Possible | No |
| Young Patient | Possible | Possible | Possible | Possible | No |
| Self-Limiting | No | No | Yes | No | No |
Possible Investigations
Likely:FBC, ESR/CRP, autoantibodies.
Possible:Urinalysis, U&E, HLA-B27, joint X-rays, synovial fluid aspiration.
Small Print:Blood film, serology, CXR, bone scan, bronchoscopic biopsy or nodal aspiration.
- FBC, ESR/CRP, blood film: WCC and ESR/CRP raised in acute inflammation and infection. Anaemia of chronic disease may be seen, and blood film will reveal sickle cell.
- Autoantibodies: Rheumatoid factor is positive in most cases of RA (if negative, consider measuring anti-CCP), but is also positive in many autoimmune diseases and chronic infections; antinuclear factor is positive in 98% of cases of SLE but a similar result is obtained in 30% of cases of RA and also in many other diseases.
- Urinalysis: May reveal proteinuria or haematuria if there is renal involvement in connective tissue disease.
- U&E: To check for renal failure via renal involvement in multisystem connective tissue disease.
- HLA-B27: A high prevalence in spondoarthritides.
- Serology: May be useful to diagnose viral, or atypical systemic, infections. ASO titres, if rising, suggest recent streptococcal infection (e.g. in rheumatic fever).
- Joint X-rays: Hand X-rays may show characteristic features helping to distinguish between RA and psoriatic arthritis; pelvic and lumbar spine X-rays may show the typical changes of ankylosing spondylitis (if negative, and clinical suspicion high, a bone scan may be helpful); X-rays of affected joints may confirm clinical diagnosis of OA.
- CXR: May reveal lung malignancy.
- Synovial fluid analysis: Helps distinguish inflammatory from infective and crystal arthropathies.
- Bronchoscopic biopsy or nodal aspiration: For sarcoidosis.
Top Tips
- The connective tissue diseases can all affect almost every organ system. Take a full history so as not to miss a clue or complication.
- Check the skin as this may contribute to the diagnosis (e.g. scaly rash in psoriasis, butterfly rash in SLE, thickening of skin in sclerosis).
- Don’t overvalue autoimmune blood tests. Most diagnoses of arthritis are clinical, blood tests simply providing confirmatory or prognostic information.
Red Flags
- Suspect Reiter’s syndrome in a young male with an inflammatory oligoarthritis of the lower limbs.
- An insidious onset of symmetrical polyarthritis in the 30–50 age range, with early morning stiffness, pain and swelling of hands and feet, suggests RA.
- Pain in the wrists and ankles of a middle-aged or elderly smoker with clubbing and chest symptoms strongly suggests hypertrophic pulmonary osteoarthropathy caused by underlying lung cancer.
- Don’t overlook the patient’s occupation as this may be relevant in certain cases – for example, in vets and farm workers, brucellosis and Weil’s disease are possible infective causes.