| 1: Monoarthritis | 2-3: Oligoarthritis | >3: Polyarthritis | Causes of migratory arthritis |
|---|---|---|---|
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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 |