What are the recommended antibiotics for treating septic bursitis?

Antibiotic Treatment for Septic Bursitis

The first-line antibiotic treatment for septic bursitis should be an anti-staphylococcal agent such as cefazolin for inpatients or clindamycin for outpatients, as Staphylococcus aureus is the most common causative organism in over 80% of cases. 1

Microbiology and Pathogen Coverage

• Staphylococcus aureus is the predominant pathogen in septic bursitis, accounting for more than 80% of cases, with other gram-positive organisms making up most of the remainder 1
• Less commonly, gram-negative organisms, fungi, and other infectious agents may cause septic bursitis, which can complicate diagnosis and treatment 1
• Empiric antibiotic selection should primarily target S. aureus while considering local resistance patterns 2

First-Line Antibiotic Recommendations

For Outpatient Treatment (Mild Cases)

• Oral clindamycin 300-450 mg three times daily is recommended for patients without systemic symptoms who can be managed as outpatients 2, 3
• Alternative oral options include first-generation cephalosporins such as cephalexin 500 mg four times daily 4
• For patients with suspected MRSA, consider sulfamethoxazole-trimethoprim 160-800 mg twice daily 4

For Inpatient Treatment (Moderate to Severe Cases)

• Intravenous cefazolin 1-2 g every 8 hours is the preferred first-line agent for hospitalized patients 4, 5
• For patients with penicillin allergy or suspected MRSA, vancomycin 15 mg/kg every 12 hours IV is recommended 4
• In cases of severe sepsis or septic shock, broader coverage may be necessary with vancomycin plus piperacillin-tazobactam or a carbapenem 4

Treatment Duration and Monitoring

• Antibiotic therapy typically requires 7-10 days for uncomplicated cases 6
• More severe infections may require 2-3 weeks of treatment, with the duration proportional to how long the infection was present before treatment 6
• Monitor clinical response within 48-72 hours of initiating therapy 3
• If blood cultures are positive or there is evidence of systemic spread, longer courses may be necessary 4

Special Considerations

Surgical Management

• Surgical consultation should be obtained promptly for aggressive infections with signs of systemic toxicity 4
• Consider surgical drainage or bursectomy for patients who fail to respond to antibiotics and percutaneous aspiration 1
• Percutaneous suction-irrigation systems may be beneficial in severe cases where continuous drainage is desirable 7

Immunocompromised Patients

• More aggressive antibiotic coverage and earlier hospitalization are warranted for immunocompromised patients 1
• Consider adding coverage for gram-negative organisms in immunocompromised patients 4

Diagnostic Approach to Guide Treatment

• Bursal aspiration should be performed when infection is suspected, with fluid examined using Gram stain, crystal analysis, glucose measurement, blood cell count, and culture 2
• A high leukocyte count in bursal fluid, low bursal-to-serum glucose ratio, and positive Gram-stained smear help distinguish septic from nonseptic bursitis 6
• Blood testing (white blood cell count, inflammatory markers) can help distinguish infectious from noninfectious causes 2

Common Pitfalls and Caveats

• Failing to differentiate between septic and aseptic bursitis can lead to inappropriate treatment 3
• Delaying antibiotic therapy increases the risk of complications and prolongs the required duration of treatment 6
• Intrabursal corticosteroid injections should be avoided when infection is suspected as they may worsen septic bursitis 2
• Outpatient treatment should only be considered in patients who are not acutely ill; those with systemic symptoms should be hospitalized and treated with intravenous antibiotics 2