What is the most common source of infection in burn patients?

The Burn Wound is the Most Common Source of Infection in Burn Patients

The burn wound itself is the most common source of infection in burn patients (Answer A). According to current guidelines, burn wound infections are one of the most important and potentially serious complications that occur in the acute period following burn injury 1.

Pathophysiology and Evidence

Burn wounds create an ideal environment for infection due to several factors:

• Damage to the skin barrier following a burn disrupts the innate immune system and increases susceptibility to bacterial infection 1
• Although burn wound surfaces are sterile immediately following thermal injury, these wounds rapidly become colonized with microorganisms 1
• The burn wound creates a protein-rich, avascular environment that serves as an excellent medium for microbial growth

Infections among burn patients are common and associated with high mortality. In a series of 175 patients with severe burns, infections preceded multiorgan dysfunction in 83% of patients and were considered the direct cause of death in 36% of patients 1.

Microbiology of Burn Wound Infections

Burn wound infections typically follow a predictable pattern:

• Initial colonization by Gram-positive bacteria from the patient's endogenous skin flora or external environment 1
• Subsequent colonization by Gram-negative bacteria, usually within a week of the burn injury 1
• Polymicrobial nature is common, requiring broad-spectrum coverage when infection is suspected 1

Diagnostic Considerations

Proper sampling of burn wounds is critical for accurate diagnosis:

• Surface swabs reflect only surface colonization rather than deep tissue invasion 1
• Tissue biopsy of the advancing margin of the wound is preferred for accurate diagnosis 1
• Quantitative bacterial culture of tissue biopsy should be supplemented with histopathological examination to better assess microbial invasion 1

Comparison with Other Infection Sources

While other infection sources do occur in burn patients, they are less common than burn wound infections:

• Pneumonia has become more common in modern burn care but remains secondary to wound infection as a source 2
• Urinary tract infections and thrombophlebitis are less common sources of infection in burn patients compared to the burn wound itself 3

Management Implications

Recognition of the burn wound as the primary infection source has important management implications:

• Early excision of burn eschar is crucial to remove the source of potential infection 4
• Accurate management of the wound with early excision can substantially decrease the incidence of invasive burn wound infection 1
• Topical antimicrobials and appropriate wound dressings are essential components of infection prevention 5

Proper diagnosis and treatment of burn wound infections are critical as they can rapidly progress to invasive infection, sepsis, and multiple organ dysfunction syndrome, which remains the most common cause of death after the initial resuscitation period 6.