Acute monoarthritis



Classification of arthritis by numberof joints involved
1: Monoarthritis 2-3: Oligoarthritis >3: Polyarthritis Causes of migratory arthritis
  • Trauma
  • Infection
  • Crystal arthropathy
  • Acute osteoarthritis
  • Reactive arthritis
  • Lyme disease
  • Avascular necrosis
  • Tumour
  • Rheumatoid arthritis
  • SLE
  • Viral arthritis
  • Chronic osteoarthritis
  • Rheumatic fever
  • Infective endocarditis
  • Henoch Schonlein purpura
  • Serum sickness (esp. cefaclor sensitivity )
  • Viral arthritis
  • Septicaemia: staph, strep, mening/gonococcal
  • Pulmonary infection: mycoplasma, histoplasmosis
  • Lyme disease

Assessing monoarthritis

History:

  • Trauma?
  • Night pain, morning stiffness, systemic symptoms, recent non-articular infections
  • Sexual history, previous episodes (back pain), rash

Examination

  • Joint line tenderness, ROM, erythema, local ↑temp., swelling, muscle wasting
  • General examination for peripheral stigmata (eg occular inflam., mouth ulcers, psoriasis, erythema nodosum, vasculitic lesions )

Labs

  • FBC
  • ESR, urate
  • Renal and liver function ± blood culture ± serum for strep titres
  • Urine culture
  • Cultures for STDs if indicated
  • Arthrocentesis- sterile technique, samples:
    • Direct microscopy
    • In CUH, if ? gout, send to cytology lab for crystal micropscopy(processed OOH if discussed with consultant cytologist)
    • C & S samples
    • Samples into blood culture media
    • Fluid in FBC bottle for WCC etc
  • x-rays normal for >2 weeks even in septic

  Normal Noninflammatory Inflammatory Septic
Clarity Transparent Transparent Cloudy Cloudy
Colour Clear Yellow Yellow Yellow
WBC <200 200-2000 200-50000 >50000
PMNs <25% <25% >50% >50%
Culture Neg Neg Neg >50% +ve
Crystals None None Possibly None
Associated   OA, trauma, ARF Gout, pseudogout, spondyloarthropathies, RA, Lyme disease Gonococcal and non-gonococcal sepsis, SLE

Gonococcal septic arthritis

  • Young adults, F > M
  • From disseminated gonococcal infection
  • Complicates 1-3% of all cases of gonnorhoea
  • May have preceding migratory tendonitis or arthritis
  • ± vesiculopustular lesions, (esp. hands)
  • ± multiple painless macules on limbs & trunk
  • Generally large joints
  • Synovial fluid cultures are often negative
  • Note that reactive arthritis secondary to gonococcal infection is a separate entity
  • Treatment: Ceftriaxone or cefotaxime

Non-gonococcal septic arthritis

  • Extreme of age & immunocompromised
  • NB prosthetic joints and rheumatoid arthritis
  • Irreversible loss of joint function in 25%
  • Fatality rate is 10% (higher in rheumatoid)
  • Large joints (textbook is knee)
  • 10% SIJ, 10% are polyarticular
  • Haematogenous or local spread
  • May not be systemically unwell
  • Staph > streptococcus
  • G-ve and mycobacterium in immonocompromised
  • Joint aspirate more sensitive than blood cultures
  • Treatment: beta-lactam and an aminoglycoside / 2nd gen. quinolone until sensitivities known

Crystal arthropathies

More on the Gout / Pseudogout page

Lyme disease

  • Delayed from the time of spirochete infection
  • A history of tick bite, followed the rash of erythema chronicum migrans, is diagnostic
  • Arthritis typically an asymmetric mono- or oligoarthritis, affecting large joints
  • May be migratory

Reiters syndrome

More on the Reiter's syndrome page

Other causes of monoarthritis incude:

  • Ankylosing spondylitis
  • Tumours ( local, metastatic, haematological, or as part of a paraneoplastic syndrome)
  • Rheumatoid arthritis
  • Osteoarthritis

Reactive arthritis

  • A sterile joint inflammation that may be related to a distant infection

Infectious agents include:

  • Salmonella
  • Shigella
  • Yersinia
  • Campylobacter
  • Chlamydia
  • Streptococcus
  • Viruses such as:
    • Rubella, Hep B, parvovirus,
    • EBV, CMV, HIV, mumps

Disposal

Symptoms Diagnosis Action
Septic joint   Urgent orthopaedic referral
Skin rash, Swollen joint, unwell Sepsis...consider :psoriasis, viral, connective tissue disorders Refer rheumatology/medical SpR
Very painful joint swelling, no trauma Gout / Pseudgout Uric acid level
Diagnostic joint aspirate
NSAIDs (See gout)
GP follow up in next week
Consider "rule in" trial of colchicine
Admit if intractable pain or Dx unclear
Iritis
Non-specific urethritis
Diarrhoea & Joint pain
Reactive arthritis OPD follow up with local "Early arthritis" referral policy
Early morning stiffness, joint pains
Swelling of hand, wrist, MTP or MCPs
? Early rheumatoid arthritis OPD follow up with local "Early arthritis" referral policy
Patient well, Hx of OA, mild trauma, age > 50 Probable osteo-arthritis NSAIDs & GP follow up


Content by Dr Íomhar O' Sullivan 29/12/2010. Last updated Dr ÍOS 24/03/24.