Septic bursitis


  • Most common sites are prepatellar bursa and olecranon bursa

Clinical Features

  • Acute pain, tenderness, warmth, and erythema of affected bursa
    • None of which is seen in aseptic bursitis
  • Fever (<50%)

Differential Diagnosis


  • Plain radiograph, CT, MRI usually not helpful
  • US may help guide procedures or help with diagnostic uncertainty
  • Bursal fluid aspiration
    • Both diagnostic and therapeutic
    • Do not perform if there is evidence overlying cellulitis
  • Procedure
    • Placed in flexed position, elbow and forearm rested on surface
    • Prep and drape
    • Plus/minus local anesthesia skin wheal
    • Approach with 18-22 ga needle from posterior aspect of bursa, aspirate until bursa is flat
    • Compressing bursa to help with aspiration
    • Arthrocentesis should be performed if joint involvement suspected
  • Septic workup
    • Cell counts > 5000 - 20,000/µL depending on source
      • Predominance of PMNs
      • Cell counts < 2000/µL, with a predominant mononuclear cells highly suggestive of nonseptic bursitis
    • Gram stain and culture
      • Gram stain with variable levels of sensitivities
      • Thus, high WBC count with negative gram stain should not exclude diagnosis
    • Elevated protein
    • Reduced glucose
    • Crystal analysis



Cover Staphylococcus aureus (80-90%) and Streptococcus

Outpatient Options

Treatment followup with primary physician is important since the regimen may need extension to 3 weeks.

Inpatient Options

  • Vancomycin 25-30 mg/kg IV loading then 15-20 mg/kg IV OR
  • Clindamycin 600 mg (10/mg/kg) IV three times daily
  • Linezolid 600 mg IV BID (10mg/kg Q8hrs for pediatrics)


  • Consider admission for:
    • Extensive purulent bursitis
    • Extensive surrounding cellulitis
    • Suspected joint involvement
    • Immunocompromised
    • Failure to respond to course of PO antibiotics

See Also

External Links

  • Septic Bursitis: ED Presentation, Evaluation, and Management on


  1. Lohr KM et al. Bursitis workup. eMedicine. NOV 2017.