Burn is a coagulative necrosis of the tissues due to thermal injury.
Thermal injury to the skin causes 3 zones
of trauma which are:
1- Central zone of coagulation which separates within 2-4 weeks
2- Intermediate zone of stasis which is viable tissues that die over the next 48hours unless there is adequate oxygenation and nutrition
3- Outer zone of hyperemia which is an area of tissue edema that recovers within 7-10 days unless it becomes infected.
The degrees of burns are: 1- 1st
degree burns in which the burn involves the epidermis only.
2- 2nd degree burns in which the burn involves the epidermis and much of the dermis.
3- 3rd degree burns in which the burn involves the epidermis, the dermis, and even parts of the deep tissues.
Types of burns: The type of the burn varies according to the cause of the burn as follow:
1- Flame burns are caused by dry heat as sunlight, flames or hot objects.
2- Scalds are caused by hot fluids or steam.
3- Physicochemical burns are caused by electricity, corrosive chemicals, etc.
Symptoms of burns: The main symptoms of the burns include: pain and disfigurement.
The pain varies according to the degree and the severity of the burn. Severe burns may be sensitive to air.
Also disfigurement varies according to degree of the burn. Superficial burns lead to erythema while deep full thickness burns lead to formation of dead white area.
The partial thickness burns lead to formation of blisters which are fluid collection between the dermis and the epidermis.
Scalds are caused by hot liquids below the boiling point.
The color of the burn is red in 1st degree burns, pink to white in 2nd degree burns, and white to black in 3rd degree burns.
The texture of the skin is normal in 1st degree burns, thick with edema in 2nd degree burns, and leathery in 3rd degree burns.
Electric burns causes 3 types of skin damage which are: contact burns at the points of current entry and exit from the body, burns at the adjacent parts, thermal burns from ignition of clothing due to heat generated by the current passing through the body.
Complications of burns: Complications of burns include local complication and general complications.
The local complications include: infection and disfigurement. The infection occurs due to loss of the barrier function of the skin against the microorganisms.
The general complications include: laryngeal edema which may lead to asphyxia, neurogenic shock due to pain, hypovolemic shock due to loss of plasma and fluids, septicemic shock due to infection of the burn, fluid and electrolyte imbalance, and organ failure.
First aid measures for burns: 1- Any clothes should be removed immediately.
2- The airway should be patent.
3- The burnt area should be immersed by tap water or be covered by cold soaks.
4- Chemical burns require copious irrigation of water.
5- The burnt area should be covered by sterile towels.
6- Analgesics should be given.
7- Antitetanic serum should be given.
Treatment of minor burns (1st degree burns and small 2nd degree burns):
1- Systemic antibiotics
2- Local antiseptic lotion
3- The vesicles should be punctured and the detached tissues should be removed.
4- Proper local cream and dressing should be applied.
Treatment of major burns (large 2nd degree burns and 3rd degree burns):
1- In major burns, the patient should be admitted to the hospital.
2- Correction of shock (if present).
3- Burnt area should be cleaned by antiseptic solution.
4- Vesicles and blisters should be punctured and deroofed and the charred parts of the skin should be removed.
5- The burnt area should be left exposed under a mosquito net and should be dusted every 8 hours by antibiotic powder, or the burnt area may be covered by Vaseline gauze and absorptive dressing which is left undisturbed for 2 weeks then dressing change can be done.