Septic Arthtitis Flashcards
What is septic arthritis?
Infection occurs within a joint - native or joint replacement
Presentation?
Usually a single joint w/ rapid onset:
(1) hot, red, swollen, painful joint
(2) Stiff + reduced ROM
(3) Systemic symptoms - fever, lethargy, sepsis
Mortality?
10%
Percentage occuring in joint replacements?
1% - higher if revision
Most common organism?
Staphylococcus Aureus
Organism to rule out if sexually active/ young patient with acutely swollen joint?
Neisseria gonorrhoea (gonococcus) - rule out even if genital/urinary symptoms and think reactive arthritis
Micro of gonococcus?
Gram -ve diplococcus
How could we differentiate gout?
fluid = urate crystals, negatively birefringent
How could you differentiate pseudogout?
fluid = calcium pyrophosphate (rod-shaped), positively birefringent
How could you differentiate reactive arthritis?
Typically triggered urethritis or gastroenteritis + assoc. with conjunctivitis
Bacteria responsible for reactive arthritis?
(1) Staph aureus - most common
(2) Neisseria gonorrhoea
(3) Group A strep (strep pyogenes in young)
(4) Haemophilis influenza
(5) E. Coli
Differentials?
(1) Gout
(2) Pseudogout
(3) reactive arthritis
(4) haemarthrosis
Initial management?
- -> Synovial fluid sample (gram stain, crystal microscopy, culture + abx sensitivities)
- -> Empirical IV antibiotics until sensitivity known
Choices of antibiotics?
Local guidelines:
- Flucloxacillin + rifampicin (often 1st line)
- Vancomycin + rifampicin (MRSA, penicillin allergy, prosthetic joint)
- Clindamycin
Which organism is likely in SCD patient?
Salmonella typhimurium
Which organism is likely in new prosthetic joint?
Staphylococcus epidermidis
