1. Epidemiology and Etiology of Burn Injuries

Burns remain a significant global public health challenge, associated with high mortality and severe long-term morbidity. While domestic and occupational exposures are predominant causes, especially in low-resource settings, the establishment of specialized burn centers has demonstrably improved patient outcomes.

A. Global and National Incidence

• Global Burden: An estimated 11 million burn injuries occur annually, leading to approximately 180,000 deaths. Over 70% of this burden falls on low- and middle-income countries.
• U.S. Data: Roughly 400,000 burn-related injuries are treated each year, with about 20,000 requiring admission to specialized burn centers. Access to this specialized care reduces mortality by approximately 30% for major burns.
• Age Distribution: In high-income countries, incidence peaks in two distinct age groups: toddlers (1–4 years) and adolescents/young adults (10–19 years).

B. Mechanisms and Morbidity

• Common Mechanisms: Flame burns are the most frequent cause (43%), followed by scalds (34%), electrical injuries (5%), chemical burns (3%), and radiation burns (<1%).
• Long-term Morbidity: Survivors often face debilitating consequences, including joint contractures, chronic pain, and significant psychosocial sequelae such as PTSD and depression.

2. Pathophysiology of Burn Wounds

Thermal injury initiates a cascade of local and systemic events. It disrupts the critical integumentary barrier, unleashes a massive inflammatory response (cytokine storm), induces a profound hypermetabolic state, and, without adequate intervention, can progress to burn shock and multiorgan dysfunction syndrome (MODS).

• Barrier Loss: The destroyed epidermis leads to massive transepidermal water and electrolyte losses, impaired temperature regulation, and loss of antimicrobial peptides, creating a portal for microbial colonization and invasion.
• Local Inflammation: Release of damage-associated molecular patterns (DAMPs) triggers a local inflammatory cascade, with high levels of TNF-α, IL-1, and IL-6 causing profound capillary leakage, tissue edema, and local hypoxia.
• Systemic Inflammatory Response Syndrome (SIRS): The spillover of these inflammatory cytokines into the systemic circulation causes widespread vasodilation, increased capillary permeability, and a state of relative hypovolemia.
• Hypermetabolic State: A massive catecholamine surge drives insulin resistance and intense muscle catabolism. This state peaks 7–10 days post-burn and can persist for months, dramatically increasing nutritional requirements.
• Burn Shock: If resuscitation is inadequate to compensate for the profound fluid shifts, the result is end-organ hypoperfusion, leading to acute kidney injury (AKI), acute respiratory distress syndrome (ARDS), and coagulopathy.

3. Influence of Pre-existing Chronic Diseases

Chronic comorbidities significantly amplify the risk of infection, graft failure, and mortality in burn patients by impairing perfusion, altering immune function, and exacerbating the metabolic stress response.

Diabetes Mellitus

Diabetes is a major independent risk factor for adverse outcomes. Its impact is multifactorial:

• It causes pre-existing microvascular dysfunction, which impairs wound healing and perfusion to the zone of stasis.
• It impairs leukocyte chemotaxis and phagocytosis, increasing susceptibility to infection.
• Stress-induced hyperglycemia further worsens endothelial injury, immune function, and the risk of both bacterial and fungal infections.

4. Social Determinants of Health in Burn Patients

Patient outcomes are not solely determined by physiology. Social determinants of health—including access to care, nutrition, health literacy, and socioeconomic factors—significantly influence both the initial risk of injury and the subsequent trajectory of recovery.

Access and Referral Delays

Geographic isolation and transportation barriers can critically delay both initial fluid resuscitation and definitive wound care. Telemedicine protocols are emerging as a valuable tool to improve triage, helping to ensure that patients with large burns (>10% TBSA) or high-risk comorbidities are directed to specialized burn centers without delay.

Socioeconomic and Cultural Factors

Burn incidence is higher in communities with crowded living conditions and where unsafe cooking practices (e.g., open-flame stoves) are common. Furthermore, cultural beliefs or misinformation may cause patients or families to delay seeking care or refuse essential treatments like early surgical excision and grafting.

5. Clinical Implications and Risk Stratification

Effective management requires an early, multidimensional assessment that integrates the burn injury itself with patient-specific risk factors. Using burn-specific sepsis screening tools enables prompt intervention and the implementation of tailored preventive strategies.

Key Risk Factors for Mortality

• Injury Severity: Age > 50 years, presence of an inhalation injury, and full-thickness burns covering > 30% of Total Body Surface Area (TBSA).
• Comorbidities: Pre-existing diabetes, cardiovascular disease, and obesity are major contributors to poor outcomes.

Sepsis Screening and Biomarkers

Sepsis is a leading cause of death after the initial resuscitation phase. Standard sepsis criteria are often unreliable due to the underlying SIRS state. Burn-specific tools and biomarkers are more effective.

The Interdisciplinary Team

Optimal care is delivered by a coordinated, interdisciplinary team. This includes prehospital triage teams, burn surgeons, critical care pharmacists, nutritionists, physical and occupational therapists, and social services. Bundled care approaches that combine early excision and grafting, antimicrobial stewardship, and aggressive metabolic support are central to modern burn management.