What is the recommended management for cellulitis occurring in a burn wound, including empiric intravenous antibiotics, burn wound care, tetanus prophylaxis, analgesia, and indications for hospital admission?

Management of Cellulitis in Burn Wounds

For cellulitis complicating a burn wound, initiate empiric intravenous antibiotics targeting both gram-positive organisms (particularly Staphylococcus aureus and Streptococcus) and gram-negative bacteria if the burn is more than one week old, combined with aggressive surgical debridement of necrotic tissue, appropriate wound care, and hospital admission for patients with systemic signs or significant burns.

Empiric Antibiotic Selection

Early Burns (< 1 week)

• Target gram-positive organisms initially, as burn wounds are colonized first by endogenous skin flora including S. aureus and Streptococcus species 1
• Continuous-infusion oxacillin is highly effective for burn cellulitis caused by these organisms, achieving resolution of fever in 1.53 days and leukocytosis in 0.89 days, with 73% success rate 2
• If oxacillin fails after 2-3 days or MRSA is suspected (based on local epidemiology >20% prevalence), switch to intravenous vancomycin 1, 2

Late Burns (≥ 1 week) or Polymicrobial Infection

• Expand coverage to include gram-negative organisms (Pseudomonas, E. coli, Proteus) as these rapidly colonize burn wounds within one week of injury 1
• The infection is typically polymicrobial requiring broad-spectrum coverage 1, 3, 4
• Obtain bacterial cultures to guide antibiotic selection, particularly given altered pharmacokinetics in burn patients requiring dosing adjustments 1

Important Caveat on Prophylaxis

• Do NOT use routine systemic antibiotic prophylaxis in burn patients without signs of infection, as this does not reduce mortality and increases antimicrobial resistance 1
• Systemic prophylaxis administered for 4-14 days may reduce mortality by half, but limited perioperative prophylaxis shows no mortality benefit 1
• Topical antibiotic prophylaxis has no beneficial effects and silver sulfadiazine actually increases burn wound infection rates and prolongs hospital stay 1

Surgical Wound Management

Debridement

• Early excision of eschar and necrotic tissue is critical to substantially decrease invasive burn wound infection 1
• Surgical debridement provides mechanical reduction of pathogen burden and removes substrate for bacterial proliferation 1
• This represents the most important source control measure to prevent progression from colonization to invasive infection 1, 4

Wound Care Principles

• Clean wounds with tap water, isotonic saline, or antiseptic solution before dressing application 1
• Antiseptic dressings are appropriate for large or contaminated burns 1
• Avoid silver sulfadiazine for prolonged use on superficial burns as it prolongs healing 1
• Reserve topical antibiotics for infected wounds only, not as first-line prophylaxis 1
• Monitor distal perfusion with circular dressings to prevent tourniquet effect 1
• Re-evaluate dressings daily 1

Special Consideration for Mafenide

• Mafenide acetate has superior eschar-penetrating characteristics, making it the agent of choice for early burn wound sepsis treatment 5
• However, limit duration and area of application due to systemic toxicity with prolonged or extensive use 5

Tetanus Prophylaxis

• Administer tetanus prophylaxis according to standard wound management protocols for contaminated wounds
• This is particularly important given the disruption of skin barrier and contamination risk in burn injuries 1

Analgesia

Pharmacologic Approaches

• Short-acting opioids and ketamine are optimal for burn-induced pain management 1
• Intravenous acetaminophen is effective and safe, particularly in elderly patients 1
• Inhaled nitrous oxide is useful when intravenous access is unavailable 1
• For highly painful procedures, general anesthesia is appropriate 1
• Consider regional anesthesia techniques when anatomically applicable 1

Non-Pharmacologic Measures

• Apply topical emollients and petrolatum-based products to reduce pain 1
• Cooling limited burn surfaces (<20% TBSA in adults, <10% in children) in absence of shock reduces pain and limits burn deepening 1
• Virtual reality or hypnosis techniques may reduce pain intensity and anxiety 1

Indications for Hospital Admission

Admit patients with any of the following:

Systemic Signs

• Fever, leukocytosis, or signs of sepsis requiring intravenous antibiotics and monitoring 2, 3, 4
• Burn infections precede multiorgan dysfunction in 83% of severe burn patients and are the direct cause of death in 36% 1

Burn Characteristics

• Significant burn injuries predisposing to infectious complications 1
• Spreading cellulitis beyond the immediate burn margin 1
• Burns requiring surgical debridement or excision 1

High-Risk Patient Factors

• Male gender, older age, lower extremity burns, full-thickness burns, delays in treatment, or pre-existing diabetes all increase infection risk 4
• Patients requiring fluid and electrolyte management, prevention of insensible water losses, or intensive wound care 1

Severe Presentations

• For extensive involvement, admit to burn unit or ICU with dermatology and wound care consultation 1
• Consider pain or palliative consultation for severe presentations 1

Key Clinical Pitfalls

• Do not delay antibiotic therapy while awaiting cultures in patients with systemic signs, as burn cellulitis can rapidly progress 2, 3
• Recognize altered pharmacokinetics in burn patients requiring adjusted antibiotic dosing for efficacy 1
• Avoid prolonged topical silver sulfadiazine which paradoxically increases infection rates 1
• Do not use sustained antibiotic prophylaxis in the absence of infection signs, as this promotes resistance without mortality benefit 1
• Switch from oxacillin to vancomycin if no clinical improvement within 2-4 days rather than persisting with ineffective therapy 2