Third Degree Burns

Generality

Third-degree burns are very serious injuries that affect all layers of the skin. This event usually determines the complete destruction ( necrosis ) of the affected area.

Third-degree burns frequently result from direct exposure to open flames, but can also be caused by electricity, radiation, chemicals and other heat sources.

Third-degree burns are characterized by the formation of spots and scabs ( eschar ), brown, black or white marble. To the touch, the portion of affected skin is hard and dry (in the case of carbonization) or moist and soft (maceration) and there is almost never pain, due to damage to the nerve endings. Third-degree burns usually leave noticeable scars, as well as predispose to very severe complications.

Treatment depends on the severity of the accident and the extent of the skin surface involved. In any case, it is advisable to contact the emergency room immediately, as third-degree burns must be treated as soon as possible by specialized medical personnel .

What are

Third-degree burns (also called full-thickness or subdermal burns ) are traumatic lesions that affect the deeper layers of the skin.

In addition to the skin surface ( epidermis ) and the layer immediately below ( dermis ), hypodermis and subcutaneous tissues (such as fat and muscle) are also damaged.

Third-degree burns result in the total destruction of intradermal epithelial structures, which have the ability to regenerate the skin. In other words, spontaneous re-epithelialization from the deep layers is a remote possibility and healing is only possible with the surgical incision of the lesions and the implant of grafts. Only deep wounds involving very limited skin surfaces can heal without transplantation, starting from healthy margins. In the latter case, spontaneous healing takes a long time.

To remember

Third-degree burns are one of the worst types of accidents that can occur. The resulting injuries and associated complications can lead, immediately or later, to the death of the patient.

Causes

Third-degree burns are injuries caused by the transfer of thermal energy to the skin by:

Thermal agents : exposure to flames, red-hot metal bodies, hot vapors and liquids or other very hot objects;
Chemicals : contact with acids, alkalis or molten metals (eg hydrochloric or sulfuric acid, caustic soda);
Electricity : ex. electric shocks and electrical appliances;
Radiation : prolonged exposure to X-rays and radioactive substances.

Gravity of a burn

The factors that influence the severity of a third degree burn are:

Percentage of the total body surface affected by the lesions;
Degree of depth (level of interest of the skin and underlying layers);
Anatomical site of the lesions.

The effects of third degree burn also depend on the characteristics of the causal agent:

Temperature of heat sources or incandescent bodies (the higher the heat transferred, the greater the damage);
Exposure time (the burn is deeper, the longer the contact with the heat source lasts);
Specific heat and physical state of the burning agent (liquid burns are more extensive, while those from solids tend to be localized, but deeper; electricity is dangerous for the whole organism).

Warning! When third-degree burns involve delicate parts of the body (such as the face, hands, abdomen, feet and airways) they are particularly serious. In such cases, therefore, it is necessary to accompany the injured person to the emergency room or to call 118 with extreme urgency.

Symptoms and Complications

The third degree burns are very serious: in the affected area, the skin is completely destroyed in all its thickness.

Often, the appearance of these wounds is less impressive than that of second-degree burns, because:

There are no flittene : skin tissues and underlying ones have been damaged to the point of not having a thickness that allows the detachment and collection of the typical oozing of blisters;
There is almost never pain : the destruction of the nerve receptors of the dermis, makes the burned part insensitive to stimuli.

The typical clinical lesion of third degree burns is the eschar, which makes the part covered with spots and crusts, blackened or whitish. Depending on the damaging agent, the affected skin area is affected by carbonization phenomena (the burned skin appears stiff and dry), maceration (wet and soft) or caustication .

The healing of third-degree burns takes a very long time and leaves permanent scars . These lesions are whitish (because the vascular component is destroyed), insensitive and lacking in hair. Furthermore, the formation of keloids is possible in the scar area in the burn.

Risks and possible consequences

Circumferential third-degree burns affecting the neck, thorax and limbs are very dangerous. These lesions cause, in fact, a circular constriction of the affected site, due to the retraction and the reduced distension of the skin. This may result in less vascularization of the downstream tissues with damage, sometimes irreversible (if the eschar completely surrounds an arm, for example, the local ischemia that follows can threaten the vitality of the limb itself or of the fingers). To avoid possible complications, it is necessary to urgently provide the full-thickness incision of the lesion ( escarotomy ).
The scars that result from a third degree burn should be monitored at regular intervals, as they can predispose, after many years, to the development of skin tumors .
Third-degree burns can become infected : damage to the skin barrier makes the patient vulnerable to pathogens. In severe cases, the passage of bacteria into the blood ( septic state ) and the spread of infection to other parts of the body may occur. Particularly at risk are newborns and the elderly over 60, especially if they have chronic diseases (eg diabetes).
The third degree burn can induce a state of general suffering, called " burn shock ". This condition affects various organs such as the brain, digestive system and kidneys. Another life-threatening event for the burn patient is hypovolemic shock, secondary to the loss of fluids through injury to the skin and to water and electrolyte imbalance.

Diagnosis

In the emergency room, the doctor assisting the injured person must first check the vital functions, then proceed with the evaluation of third-degree burns .

To determine the severity of the clinical picture, it is necessary to consider the following parameters:

Extension, depth and anatomical site of lesions;
Etiological agent (note: burns caused by chemicals and electricity cause more serious damage than is evident);
Any injuries associated with the burn;
Dynamics of the accident (for example, fires in an enclosed area have a high probability of causing inhalation injuries);
Age and pre-existence of diseases that can worsen the patient's general condition (note: the prognosis is worse when the patient is an elderly person, a carrier of chronic diseases, such as diabetes, or a child under 3 years of age);
Factors associated with the quality of the aid provided to the victim (eg time interval between incident and the beginning of any resuscitation therapy).

In the emergency room, the doctor monitors the patient, performing blood chemistry, electrocardiogram and blood gas analysis (indispensable for assessing carboxyhemoglobin, a sign of inhalation by carbon monoxide).

Treatment

Treatment of third-degree burns is of medical relevance. The subject must be immediately accompanied to the emergency room or transported to the hospital with an ambulance.

First intervention

Waiting for the intervention of the doctor and / or hospitalization:

Remove the injured person from the heat source or from the burning agent : extinguish the flames in the event of a fire, cut clothes in the event of burns from boiling liquids or chemicals, remove hot objects and electric current from the skin, etc.
Move the victim from the closed environment to avoid the appearance of lesions to the respiratory tract from boiling fumes and vapors (inhaling these elements produces thermal and chemical damage); during a fire, the victim is exposed to carbon monoxide and cyanide poisoning.
Cool the burn area with fresh water (at about 15 ° C) from the tap or immersing the part for about 5-15 minutes. Even when the injured part has been removed from the heat source, in fact, the damage to the skin continues. The cold is able to interrupt this destructive process, as well as having a pain-relieving effect. In the case of contact with chemical substances (eg quicklime), on the other hand, contact with water is absolutely to be avoided, as it could cause greater damage.
Protect injured areas to avoid external contamination of burned areas; this intervention can be carried out with sterile dressing material or the use of clean and wet cotton linen, taking care not to compress the damaged part.

What to pay attention to :

In the case of a very large third degree burn, cooling should not last more than five minutes. The risk is to cause a dangerous drop in body temperature (hypothermia). In the same way, the application of ice directly on the area must be absolutely avoided, as it could cause further injury.
Do not attempt to remove clothes if they are tenaciously attached to the skin: this operation can only be carried out by specialist doctors (in addition to clothing, there is a risk of tearing the skin, worsening the situation).
Do not apply products of any kind on the burn: oils and other substances do not cool the tissues and can infect the lesions, in addition to preventing a precise evaluation.
In the case of third-degree burn caused by a chemical agent, it is very important to carry a sample of the substance, possibly in its original packaging. This is needed by the emergency room doctor to set the best therapeutic intervention.

During hospitalization, the lesion must then be checked regularly to detect the progress of reparative processes and medicated with specific gauze or ointments to protect the burned part from infection.

In hospital, supportive treatment may include the use of drugs to be taken orally and / or locally applied, in order to reduce pain and prevent infective complications. Third-degree burns that result in severe impairment of respiratory function due to involvement of the upper airways may require intubation or a tracheostomy.

Surgical therapy

Generally speaking, third-degree burns do not undergo spontaneous healing, in the absence of surgery.

In the hospital, after the initial medical therapy to prevent infections and dehydration, third-degree burns require surgical treatment to remove necrotic tissues ( escarotomy ). This intervention involves the incision at full thickness of the lesion and the covering of the skin with the implant of grafts (cutaneous or synthetic).

To promote healing, the third degree burn may make the transplantation of the epidermis necessary .

The unsightly scars can then be corrected with plastic surgery .

In very serious cases, if there is no possibility of recovery, a third degree burn can lead to amputation of the damaged part.