Acute Monoarthritis
NHS Tayside RefGuide
Warning
History
- Symptoms and course of events (heat, swelling, tenderness, restricted movement, timescale, systemic symptoms?)
- Prosthetic or native joint
- Existing joint pathology eg RA
- Precipitating factors
- Recent infections (GI/GU/URTI)
- Trauma
- Immunosuppressive treatment or condition
- Coagulopathy/haemaglobinopathy
- Other joint involvement
- Sexual history
- Social Hx (drug use, alcohol excess, occupation).
Examination
- Affected joint: swelling, erythema, warmth, tenderness
- Overlying skin damage eg ulceration
- Signs of IV drug use
- Presence of gouty tophi
- Signs of fever/sepsis
- Presence of psoriasis (?PsA).
Potential causes
- Septic arthritis
- Crystal arthritis (Gout, Calcium Pyrophosphate Disease [pseudogout])
- Reactive Arthritis
- Monoarticular presentation of polyarthritis
- Intra-articular injury (fracture, meniscal tear etc)
- Haemarthrosis
- Inflammatory OA.
NB mimics e.g. cellulitis, bursitis, phlebitis.
Investigations
If there is a concern regarding septic arthritis, prompt joint aspiration is required. Please contact orthopaedics for any joint other than knees, or for any prosthetic joints.
- Aspiration from an area of clear skin: send for joint aspirate C&S (includes microscopy and crystals – call lab to inform them of sample)
- Peripheral blood cultures
- Obtain relevant cultures. If suspected gonococcus, request PCR
- FBC, U&Es, CRP, urate (NB – may be normal in acute gout)
- X-ray joint (?evidence of chondrocalcinosis)
- Coagulation screen if appropriate
- MRI if concerns re osteomyelitis.
Management
- Septic arthritis – d/w orthopaedics for ?washout
- Uncomplicated (likely gram positive organism): as per Antibiotic Man; amend according to sensitivities
- Complicated (recent surgical or GI procedure, likely gram negative organism): d/w ID or microbiology for antimicrobial advice
- Reactive arthritis
- Full dose NSAID with gastric protection
- Treat precipitating factors (e.g. Chlamydia)
- Gout
- See rheumatology Gout guidelines for full details
- NSAID, Colchicine or Steroids + PPI
- Pseudogout
- As for gout
- Local steroid injection.