Polyarthritis

Pain/swelling affecting 5 or more joints.

History

• The patient’s age and gender can increase the probability of some disorders
  • e.g. premenopausal women are more likely to develop SLE and rheumatoid arthritis than men.
  • Women are more likely to develop fibromyalgia
  • Gout is far more common in men
  • Reactive arthritis and spondyloarthropathies tend to be more common in younger individuals with a slight male preponderance
  • Osteoarthritis, polymyalgia rheumatica and giant cell arteritis are more common in older people
• Ask about the pain:
  • Site- The pattern of involvement may suggest a partcular diagnosis.

From left to right: Rheumatoid affecting MCP, PIP, MTP and other joints in a symmetrical fashion.
Psoriatic arthritis affecting PIP, DIP and large joints in an asymmetrical fashion. Ankylosing spondylitis affecting the axial skeleton and large peripheral joints in an asymmetrical fashion. Osteoarthritis affecting the DIP, base of thumb, knees, hips, lumbar and cervical spine.

• Onset- hours suggests gout; days-weeks suggests inflammatory cause or osteoarthritis
• Timing- Relapsing-remitting is suggestive of inflammatory conditions.  Pain/stiffness worse in the morning is classical of inflammatory disease whereas worsening throughout the day can suggest osteoarthritis
• Exacerbating/relieving factors- similarly improvement with movement suggests inflammatory disease; worsening suggests osteoarthritis
• A migratory
• Ask about associated symptoms
  • Skin, nails and mucous membranes
    • Psoriasis, nail pitting and dystrophy -> Psoriatic arthritis
    • Reynaud’s phenomenon -> SLE, systemic sclerosis
    • Photosensitivity, Livedo reticularis -> SLE
    • Splinter haemorrhages, nail-fold infarcts -> vasculitis
    • Oral ulcers -> SLE, reactive arthritis, Behcets
    • Large nodules on the extensor surfaces -> RA, Gout
    • Finger clubbing -> Enteropathic arthritis, metastatic lung cancer, infective endocarditis
  • Eyes
    • Uveitis -> Seronegative spondyloarthropathies
    • Conjunctivitis -> Reactive arthritis
    • Episcleritis, scleritis -> RA, vasculitis
  • Other
    • Urethritis -> Reactive arthritis
    • Fever, weight loss -> systemic inflammatory disease
    • Take a full systemic enquiry (resp, CVS, abdo symptoms)
• Take a past medical history, family history (may be particularly relevant in spondyloarthropathies- HLA-B27, rheumatoid arthritis, Heberden’s nodes of OA), social history

Examination

• Examine the joint(s) for signs of inflammation (hot, tender, swollen)
  • Check for pattern of involvement (asymmetrical vs symmetrical)

Investigations

• Blood tests
  • FBC
    • Anaemia – can be a sign of inflammatory disease (particularly SLE, RA, IBD and human parvovirus B19)
    • Thrombocytopenia- can be seen in SLE and hParvoB19
    • Thrombocytosis- can be seen as part of the acute-phase reaction, vasculitis, infection
    • Leukopenia- SLE, RA, Sjogrens, hParvoB19
    • Leukocytosis- RA, vasculitis, reactive arthritis, infection
    • Eosinophilia- SLE, RA, IBD, sarcoidosis, dermatomyositis, scleroderma, Churg-Strauss, polyarteritis nodosum,
  • U&Es- reduced kidney function
  • ESR/PV- Rarely diagnostic but can often be raised and may be a good marker of disease activity
  • CRP
  • Antibodies
    • Rheumatoid Factor- a strongly positive RF increases the likelihood of RA, and correlates with a less favourable outcome.
      • Note that 38% of patients with RA do not have a positive RF and RF can be positive in other conditions e.g. SLE, Sjogrens, infection etc and is positive in around 1-2% of healthy individuals (up to 15-20% in patients >65)
    • Anti-CCP- more specific for RA
    • Other rheumatological antibodies e.g. anti-nuclear antibody; ANCA etc
  • X-rays of the joint aren’t specific but may show some characteristic appearances
  • Joint aspiration may be useful if there is suspicion of a crystal or septic arthritis

Causes

• Common
  • Rheumatoid Arthritis
    • Symmetrical, small and large joints, upper and lower limbs
  • Viral Arthritis e.g. Human Parvovrius B19
    • Symmetrical, small joints, may be associated with rash and prodromal illness, self-limiting
  • Osteoarthritis
    • Symmetrical, targets PIP, DIP and first CMC joints in hands, knees, hips, back, neck; associated with Heberden’s and Bouchard’s nodes
  • Psoriatic Arthritis
    • Asymmetrical, targets PIP and DIP joints of hands and feet (sausage appearance on examination), nail pitting, large joint also affected
  • Ankylosing Spondylitis and Enteropathic Arthritis
    • Tends to affect large joints, lower more than upper limbs, possible history of inflammatory back pain
  • SLE
    • Symmetrical, typically affecting small joints
• Less Common
  • Juvenile idiopathic arthritis
  • Chronic gout
  • Chronic sarcoidosis
  • Polymyalgia rheumatica
• Rare
  • Systemic sclerosis and polymyositis
  • Hypertrophic osteoarthropathy
  • Haemochromatosis
  • Acromegaly