How should a burn wound complicated by cellulitis be managed?

Treatment of Burn-Associated Cellulitis

Burn wound cellulitis requires a combined approach of early surgical debridement with excision of necrotic eschar plus systemic antibiotics targeting polymicrobial flora, specifically covering both Gram-positive organisms (initially) and Gram-negative bacteria (after one week), while avoiding routine prophylactic antibiotics in the absence of clinical infection. 1

Surgical Management - The Foundation

Early excision of eschar is the single most important intervention to substantially decrease the incidence of invasive burn wound infection and cellulitis 1. The thermal injury disrupts the innate immune barrier, and removal of necrotic tissue mechanically reduces pathogen burden 1.

• Surgical debridement should focus on removing all necrotic tissue to prevent progression from colonization to invasive infection 1
• Deep irrigation serves to remove foreign bodies and pathogens, but avoid high-pressure irrigation as it may spread bacteria into deeper tissue layers 1

Antibiotic Therapy - When Cellulitis is Present

Initial Empiric Coverage

When cellulitis has developed (spreading erythema beyond burn margins, systemic signs), systemic antibiotics are indicated 1:

For early cellulitis (first week post-burn):

• Continuous-infusion oxacillin is highly effective, achieving 73% success rates with faster resolution of leukocytosis (0.89 days) and fever (1.53 days) compared to other agents 2
• Alternative: Cefazolin or nafcillin for Gram-positive coverage 1
• If oxacillin fails after 2-3 days, switch to vancomycin (achieves 100% success rate after oxacillin failure) 2

For cellulitis developing >1 week post-burn or polymicrobial infection:

• Burn wound infections are typically polymicrobial, initially colonized by Gram-positive bacteria but rapidly colonized by Gram-negative bacteria within a week 1
• Broad-spectrum coverage is required: Vancomycin PLUS piperacillin-tazobactam or a carbapenem (imipenem/meropenem) 1
• This regimen covers MRSA, streptococci, and Gram-negative organisms including Pseudomonas aeruginosa 1

MRSA Considerations

Administer anti-MRSA antibiotics (vancomycin or linezolid) when: 1

• Local epidemiology shows >20% MRSA in invasive hospital isolates
• High community MRSA circulation
• Patient has MRSA risk factors (prior hospitalization, healthcare exposure)
• Cellulitis develops in hospitalized burn patients

Duration and Monitoring

• Treatment duration averages 5-6 days for cellulitis resolution 2
• Obtain bacterial cultures to guide antibiotic selection, especially given drug resistance patterns 1
• Critical caveat: Altered pharmacokinetics in burn patients require adjusted dosing to maximize antibiotic efficacy 1

Topical Antimicrobials - Adjunctive Role Only

Do NOT use topical antibiotics as primary treatment for established cellulitis - they are for prophylaxis only 1, 3:

• Silver sulfadiazine is contraindicated for cellulitis as it significantly increases burn wound infection rates (OR 1.87) and prolongs hospital stay by 2.11 days compared to dressings 4
• Mafenide acetate has superior eschar penetration for early burn wound sepsis but requires limited duration/area due to systemic toxicity 3
• Topical agents should be reserved for wound colonization prevention, not active infection treatment 3

Prophylactic Antibiotics - NOT Recommended

Routine antibiotic prophylaxis should NOT be administered to burn patients without clinical infection 1:

• Prophylactic penicillin does not prevent cellulitis or burn wound sepsis (p=0.340) 5
• Systemic prophylaxis shows no evidence of reducing burn wound infection rates 4
• Universal prophylaxis risks selecting antibiotic-resistant organisms without clinical benefit 1, 5

Adjunctive Measures

• Elevation of affected extremities accelerates healing when swelling is present 1
• Appropriate wound dressings protect from contamination and reduce pain, but should not delay resuscitation 1
• Ensure tetanus prophylaxis is current 1

Common Pitfalls to Avoid

• Do not delay surgical debridement while waiting for antibiotic effect - early excision is paramount 1
• Do not use silver sulfadiazine for active cellulitis - it worsens outcomes 4
• Do not give prophylactic antibiotics routinely - reserve for documented infection 1, 4, 5
• Do not underdose antibiotics - burn patients have altered pharmacokinetics requiring dose adjustments 1
• Do not forget to switch from oxacillin to vancomycin if no improvement by day 2-3 2