Burns: Clinic, diagnosis and treatment

• Burns are tissue injuries caused by exposure to heat, cold, chemicals, electricity, radiation or mechanical energy.
• Burns can be classified into three categories based on their depth: first-degree burns, which affect only the epidermis; second-degree burns, which also affect the dermis; and third-degree burns, which affect the deep layers of the skin and subcutaneous tissue.
• Burns can cause severe pain, inflammation, loss of sensation, tissue necrosis and permanent damage.
• Treatment of burns depends on their severity and may include local care, surgical interventions, and rehabilitative therapies^1,2.

The physiopathology of burns is complex and depends on the depth, extent and cause of the burn^2,4:

First-degree burns

• Are burns that cause superficial damage to the epidermis, which is the top layer of the skin.
• The cells of the epidermis are damaged or destroyed, resulting in local inflammation and severe pain².

Intermediate second-degree burns

• Cause deeper damage, reaching the dermis, the layer of skin beneath the epidermis. Blood vessels are damaged, causing plasma to leak and fluid to accumulate in the tissue.
• This can cause blistering, skin loss and increased pain.
• They can be separated into two subclasses²:
  • The second superficial degree: it shows total involvement of the epidermis and the papillary dermis. The clinical sign is a blister, which then leaves a pink, oozing, painful erosion. Healing is spontaneous in less than 14 days, but residual dyschromia is possible.
  • The second deep degree: it shows epidermal destruction with damage to the reticular dermis, but preservation of the appendages. The clinical sign is a blister with a reddish-brown background, leaving a whitish, atonic, hypoesthetic erosion with detachment of the cutaneous appendages. Healing is slow, taking 3 to 6 weeks, often at the cost of residual hypertrophic scars.

Distinguishing between a superficial and a deep second-degree burn can be difficult, especially since the burn may worsen over time².

Third-degree burns

• Cause damage to the deep layers of the skin and subcutaneous tissue, resulting in loss of sensation and tissue necrosis.
• If smoke or fumes are inhaled, these burns can also cause damage to internal organs such as the lungs or the nervous system².

Fourth degree burns or carbonization

• We speak of fourth degree burns or carbonization in case of fat or muscle damage.
• The clinical sign is the white or black aspect, somewhat cardboardy and anesthetized.
• No healing is possible except from the edges, which are often far apart.
• Surgical treatment is mandatory^1,5.

The inflammatory response is a key element in the physiopathology of burns. Immune cells, such as neutrophils and macrophages, migrate to the burn area to remove dead cells and tissue debris. However, this excessive inflammatory response can cause damage to healthy tissue, resulting in a systemic response called systemic inflammatory response. Cytokines, signalling molecules involved in inflammation, are released from the damaged cells, and can cause disruptions in clotting, blood pressure, and organ function⁴.

Acute Burn²

In the case of an acute burn, several factors must be determined:

Extent of injury

• Wallace's Rule of Nines is a tool used to assess the extent of body burns in adults. To use Wallace's Rule of Nines, the body is divided into nine equal sections and the percentage of burns in each section is calculated. Using this information, the physician can assess the severity of the burn and plan appropriate treatment.
• It is important to note that this rule is primarily used for adults and may not be accurate for children, obese or skinny people because their total body surface area may vary.

Depth of lesions

• Simple erythema: superficial first-degree burn.
• Erythema + blisters with exposed, red, moist but sensitive dermis: second-degree burn, superficial or intermediate.
• Insensitive dermis turned white or charred: third-degree burn.

Contributing factors

• Origin: 
  • Liquid.           
  • Solid.
  • Gas.
  • Electricity.
• Observations:
  • Ensuring whether eyes were affected or not as it warrants an urgent consultation with an ophthalmologist.
  • Burns present on sensitive areas (face, neck, genitals).
  • Involvement of areas susceptible to functional sequelae (hands, folds, periorificial region).
  • Circular burns on limbs.
• Terrain:
  • Children - elderly patients – at-risk patients (heart failure, respiratory difficulties, renal function, alcoholism, diabetes).
  • Septic conditions with major risks of superinfection.
• Commonly associated signs: signs of shock:
  • Blood pressure.
  • Temperature.
  • Pulse.
  • Other lesions (fractures).

Chronic Burn³