Treatment of Septic Bursitis
Septic bursitis requires immediate antibiotic therapy targeting Staphylococcus aureus (the causative organism in >80% of cases), combined with bursal drainage, with treatment duration of 7-10 days for uncomplicated cases.
Initial Management and Diagnosis
- Obtain bursal fluid aspiration for culture and analysis before starting antibiotics, but do not delay antimicrobial therapy more than 45 minutes 1, 2
- Bursal fluid typically shows elevated white blood cell count (often >3000 cells/mm³) and bacteria on Gram stain 3
- Blood cultures should also be obtained if systemic signs of infection are present 1
Antibiotic Therapy
Empiric Treatment
- Initiate IV antibiotics within one hour of diagnosis targeting gram-positive organisms, particularly S. aureus 4, 2
- For severe cases requiring hospitalization or with extensive cellulitis, use IV cloxacillin 2g every 4 hours (or equivalent anti-staphylococcal penicillin) 5
- For MRSA coverage or penicillin allergy, use IV vancomycin 15-20 mg/kg every 8-12 hours 6
- In patients with fulminant infection, systemic toxicity, or immunocompromise, consider adding gentamicin 240 mg/day IV for 5-7 days to the beta-lactam 5, 7
Duration and De-escalation
- Continue IV antibiotics until clinical improvement (typically 4-7 days), then transition to oral therapy 5, 8
- Total antibiotic duration should be 7-10 days for uncomplicated septic bursitis 4, 2
- Longer courses (14+ days) are appropriate for slow clinical response, immunocompromised patients, or if bacteremia is present 4, 2
- Narrow therapy once culture results and sensitivities are available 4, 2
- Serial bursal aspirations every 2-3 days should demonstrate culture sterility within 4 days on average; continue antibiotics for 5 additional days after documented sterility 8
Drainage Procedures
Aspiration vs. Surgical Drainage
- Perform repeated percutaneous needle aspiration as first-line drainage method 8, 7
- For severe cases, consider percutaneous placement of suction-irrigation system with local antibiotic irrigation (1% kanamycin and 0.1% polymyxin) 9
- Surgical drainage or bursectomy is indicated for patients who fail to respond to IV antibiotics and repeated aspiration within 48-72 hours 7
Indications for Hospitalization
Admit patients with any of the following 7:
- Fulminant local infection with extensive cellulitis
- Evidence of systemic toxicity (fever, sepsis)
- Immunocompromised state
- Failed outpatient management
Monitoring Response
- Assess clinical improvement within 48-72 hours of initiating appropriate therapy 1
- Persistent symptoms beyond 72 hours suggest inadequate drainage, inappropriate antibiotic selection, or complications 1
- Serial aspirations should show decreasing white blood cell counts and negative cultures by day 4 8
- Delayed treatment (>2 weeks from symptom onset) prolongs time to culture sterility and increases risk of treatment failure 8
Common Pitfalls
- Early delay in diagnosis and treatment is strongly correlated with prolonged culture-positivity despite adequate antibiotics (r=0.68, P<0.001) 8
- Single aspiration without serial drainage often leads to treatment failure 3, 8
- Premature discontinuation of antibiotics before documented culture sterility increases recurrence risk 8
- Failure to consider MRSA in patients with healthcare exposure or previous antibiotic use 6, 5
- Inadequate drainage in patients with loculated or extensive bursal fluid collections 9, 7