II. Mechanism
- Often follows acute Trauma
III. Causes
- Staphylococcus aureus (80-85% of cases)
- Streptococcus Pyogenes and other species
- Staphylococcus Epidermidis
- Enterococcus (rare)
- Escherichia coli (rare)
- Pseudomonas aeruginosa (rare)
- Candida (rare)
IV. Risk Factors
- Common Predisposing Factors (present in 50% of cases)
- Diabetes Mellitus
- Chronic Kidney Disease
- Rheumatic disorders
- Alcoholism
- Immunocompromised state (e.g. HIV Infection, Chronic Corticosteroids)
- Other Risk Factors
- Male gender
- Trauma or recent procedures
- Gouty Arthritis
- Dermatologic conditions (e.g. Psoriasis, Eczema)
V. Symptoms
- Fever (variably present)
- Bursal pain, redness and swelling
VI. Signs
- Inflammation of skin overlying bursa
- Bursa erythema, warmth, and effusion
- Normal range of motion
- Range of motion will however increase pain when bursa is compressed (esp. flexion)
- Contrast with Septic Arthritis
- Restricted joint range of motion is a red flag for deep infection or Septic Arthritis
- Regions affected
- Deep bursa infections (e.g. subacromial, ischial, trochanteric) are rare
- Superficial bursa infections are most common
- Septic Olecranon Bursitis
- Septic Prepatellar Bursitis
VII. Labs
-
Complete Blood Count with differential
- May show Leukocytosis with Left Shift
-
Bursa Aspiration for Gram Stain and culture
- See Bursa Aspiration
- Indications
- Historically has been recommended in all cases of Septic Bursitis
- However, empiric Antibiotic management without aspiration may be a safe and effective strategy
- Findings suggestive of Septic Arthritis
- Leukocyte count >10,000 with >50% Neutrophils (PMNs)
- Bursal fluid PMNs >1000/mm3 (typically >2000/mm3)
- Rising MRSA rate dictates culture-directed therapy
- Culture Test Sensitivity >67% (lower with prior Antibiotics)
VIII. Imaging
-
Ultrasound
- Indications
- Deep bursa infection suspected
- Guidance for Bursa Aspiration
- Findings
- Bursal effusion
- Edema
- Bursal wall cobblestoning and thickening
- Indications
- Joint Xray
- MRI
- Consider in the rare suspected case of deep bursal infection (e.g. subacromial, ischial, trochanteric)
IX. Complications
- Contiguous spread to surrounding tissue (including Septic Arthritis)
- Abscess
- Cutaneous fistula
- Aseptic sympathetic joint effusion
- Diagnosis of exclusion
- Differentiate from Septic Arthritis with Arthrocentesis
X. Management
-
General measures
- Moist heat
- Splinting
- Repeated aspiration or incision, drainage as needed
-
Antibiotics
- Cover Staphylococcus and Streptococcus
- Modify Antibiotics based on culture of aspirate
- Duration of therapy: 14-21 days
- Shorter courses may be effective, and are not a risk for recurrent infection
- Perez (2010) J Antimicrob Chemother 65(5): 1008-14 +PMID:20197288 [PubMed]
- Mild infection
- First-line Antibiotics for MSSA
- Oral: Dicloxacillin or Cephalexin
- IV: Cefazolin, Oxacillin or Nafcillin
- Consider MRSA coverage
- Trimethoprim-sulfamethoxazole
- Doxycycline
- Clindamycin (high rates of MRSA resistance, and induced resistance risk)
- First-line Antibiotics for MSSA
- Severe infection (treat as presumed MRSA)
- Start with Vancomycin IV
- Alternatives: Linezolid, Daptomycin
- Transition to oral agents based on culture results
XI. References
- (2016) Sanford Guide, accessed on IOS 2/16/2017
- (2006) UpToDate, accessed 12/19/06
- Funk and Hurely (2022) Crit Dec Emerg Med 36(1): 18-9
- Koutouzis (2006) Marx: Rosen's Emergency Med
- Small (2005) Infect Dis Clin North Am 19:991-1005 [PubMed]
- Lopez (2006) Infect Dis Clin North Am 20:759-72 [PubMed]
- Khodaee (2017) Am Fam Physician 95(4): 224-31 [PubMed]