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
  • Lyme disease
  • Reiter’s syndrome
  • Ankylosing spondylitis
  • Gonococcal arthritis
  • Rheumatic fever
  • 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, movements, erythema, local increases in temperature, swelling, loss of joint function, muscle wasting.
  • General examination for peripheral stigmata ( eg occular inflammation, 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
    • 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 haave preceding migratory tendonitis or arthritis.
  • +/- vesiculopustular lesions, (esp. hands)
  • +/- multiple painless macules on limbs and trunk
  • Generally large joints.
  • Synovial fluid cultures are often negative
    • …. the gonococcus has to be grown from elsewhere
  • Note that reactive arthritis secondary to gonococcal infection is a separate entity.
  • Treatment: Ceftriaxone or cefotaxime

Non-gonococcal septic arthritis

  • Extreme of age and 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 generation 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 syndroms 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

Clear cut septic joint

or

Septic infected joint

  

Urgent orthopaedic referral

Skin rash

Swollen joint

Unwell

Sepsis

Consider :psoriasis, viral, connective tissue disorders

Referral rheumatology SpR or on-take 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
Admit if intractable pain or Dx unclear 

Iritis
Non-specific urethritis
Diarrhoea & Joint pain

Reactive arthritis

OPD follow up

Local "Early arthritis" referral policy

Early morning stiffness, joint pains
Swelling of hand, wrist, MTP or MCPs

? Early rheumatoid arthritis

OPD follow up

Local "Early arthritis" referral policy

Patient well

Background of OA

Mild trauma

Age > 50

Probable osteo-arthritis

NSAIDs

 

GP follow up

Links