Table of Contents

Burn and Scald

Burn is an injury of integuments and underlying tissues, occurring due to high temperature or chemical substances. Scald is an injury caused by hot liquids or stream.

Burn may be defined as tissue changes that occur on excessive absorption of heat by skin.

Scald is an injury caused by hot liquids or stream. Scald is likely to be more injurious than because of the hot liquid may penetrate into the deeper part of tissues.

Classification of burns

Burns are classified in four degrees based on the depth and severity of burn-

First Degree burn (Superficial burn)
Second degree burn (partial thickness burn)
Third degree burn (Full thickness)
Fourth degree burn

1. First Degree burn (Superficial burn)

In First Degree (Superficial) burn, epidermis is affected and transient erythema, sometimes vesicle formation and desquamation of the epidermis occurs. Epidermal burns look red, are painful and heal rapidly.

2. Second degree burn (partial thickness burn)

In Second degree burn (partial thickness burn), depth extends to the mid dermis. Loss of epidermis is complete. Capillaries and venules in the dermis is dilated, congested and exude plasma. There is erythema, coagulative necrosis of epidermal cells and vesicle formation. Healing is rapid and complete by the regeneration of epithelium unless there is involvement of secondary infection.

3. Third degree burn (Full thickness burn)

Third degree burn (Full thickness burn) is characterized by coagulation of epidermis and dermis. Severe edema of the sub cutis develops and dry gangrene of the damaged tissue occurs. The epidermis is desiccated and charred with presence of black layer in skin. Permanent scarring occurs due to healing by granulation. Full thickness burn is insensitive to pain because of damage of cutaneous nerve endings.

4. Fourth degree burn

In Fourth degree burn, subcutaneous fascia and deeper tissue like muscles, bones etc are involved. The clinical features are similar to those described in third degree burn. Repair is by scar formation preceded by sloughing of the necrotic tissue.

Etiology of burns

Etiology of Thermal burns

Thermal injuries like direct heat, flame and Scalding cause burns.

Etiology of Electric Burns

Electric causes like Electric cord exposure and lightning produce burns.

Etiology of Chemical Burns

Injuries caused by chemicals like strong acids and alkalis, solvents, petroleum distillates and hot tars are referred to as chemical burns.
The chemical produces localized necrosis of skin and deeper tissues with which it comes in contact.
The degree of tissue destruction depends on the strength of the chemical and the duration of contact.
Chemical causes local coagulation of proteins and necrosis

Clinical Signs of burn

Clinical Signs of Thermal burns

Superficial thermal burn causes hyperemia, desquamation and pain.
Partial thickness thermal burn causes exudation, pain, decreased sensitivity.
Full thickness thermal burn are White, black or brown, leathery escher, and causes subcutaneous edema and little or no pain.

Clinical Signs of Electrical burns

Electrical burns causes no pain.
Electrical burns are well-circumscribed cold, blood less, pale yellow lesion.

Clinical Signs of Chemical burns

Line of demarcation between dead and healthy tissue present in Chemical burns.
Devitalised tissues may get infected due to chemicals.
Chemical burns cause formation of ulcer which heals gradually.

Treatment of Burns

The therapeutic measures must be aimed at-

Termination of painful stimuli and improvement of the nervous system function for avoiding shock
Reduction of autointoxication
Prevention of infection
Promotion of rejection of coagulated Skin and tissues
Creation of favorable conditions for regeneration of skin

Anti-shock measures are to be provided to prevent shock that may arise as burn complication.

Burn may lead to renal failure and fatty infiltration of liver thus appropriate care should be extended to combat the complication.

Application of ice (3-17ºc) pack wrapped in a soft towel and cold water for 30 minutes or covers it with wet towels. This also helps to remove caustic substances (acid or alkali) if these are the cause.

Hair should be removed and gently clean from the site. Necrotic tissue should be debrided. The area should be swabbed with weak vinegar (half water, half vinegar) using cotton wool or cloth.

Topical antibacterial ointments may be applied to prevent the animal from post burn sepsis. Several topical commercial products like Aloevera cream, Silver sulphadiazine cream (Indo-Pharma), Silver nitrate 0.5% Solution, chlorhexidine 0.5% Solution, gentamycin sulphate 0.1% cream, povidone iodine cream can be used. Soothing and protective preparations like Badional gel (Bayer), Caladryl cream (Park Davis), Burnol (Knoll) may be used as burn dressing.

Drugs like gentian violet, picric acid, acriflavin and tannic acid should not be used as far as possible as they delay the healing process by damaging the living cells.

Analgesic should be given to reduce pain.

Hypovolemic shock and acidosis are to be prevented by supplementation of large quantities of fluid (Dextrose 5%) including 4% sodium bicarbonate.

The treatment in chemical burns should include washing with lots of plain water and neutralisation of the offending chemicals. Acids can be neutralised with 2-3% solution of sodium carbonate or milk, while alkali with 2% vinegar, citric or boric acid. Finally soothing ointment like olive oil may be applied. If shock occurs, keep the animal warm with heating pads or hot water bottles and a blanket of heavy coat. A burn patient (pet) should be provided with ample warm fluids to drink and this may be given in the form of milk or glucose water.