Electrical burn

Electrical burns may be caused by a number of sources of electricity, such as lightning, stun guns and contact with household current. You may treat minor electrical burns as you would other minor burns. A person who has been injured by contact with electricity should be seen by a doctor. Sometimes an electrical injury can cause damage to internal tissues, usually in an arm or a leg. The damage may be worse than one would expect from the burn on the skin.

Electric shocks are caused by contact with live electricity that sends an electric current through the body. Sometimes the electricity can cause a burn, often where the electricity entered or exited the body.

Electric shocks can cause little more than a fright and some pain, or they can be severe enough to knock someone unconscious and stop their heart. An electric shock can be life threatening.

Even if you can’t see a physical injury, an electric shock might cause internal damage. Even for a mild electric shock, you still need medical attention to assess whether it’s affected the heart.

Always take someone who has been shocked to the nearest emergency department for assessment.

If there is an electrical burn, you can treat it in the same way as you would any other burn. Put the burnt area under running water for at least 20 minutes then cover with a sterile gauze bandage, if available, or a clean cloth. Don’t use a blanket or towel, because loose fibers can stick to the burns.

Of all burns treated in a medical setting, 4% to 5% are electrical ¹. In the United States, accidental high voltage electrical injuries account for approximately 400 deaths per year ². The total number of electrical deaths is approximately 1,000 yearly in the United States. Electrical injuries in adults are most commonly occupational; in children, household electrical injuries are most common. Males are more commonly injured via electricity than females ³. The hands are the most common source point, followed by the head. Feet are usually the ground point.

Are there complications of electric shocks or burns?

The most common complication of an electrical injury is infection.

Some people have damage to the brain, which can cause seizures, depression, anxiety or personality changes.

Electric shocks or burns causes

Electrical injuries occur when the human body comes in contact with an electrical source, either directly or through material that is a conductor. For example, a utility worker may fall from a bucket truck and instinctively grab a power line to catch himself, causing electrical injury; alternatively, the worker may be holding a pole that comes in contact with a power line, causing him to sustain electrical injury. More commonly, a person becomes a victim of electrical injury at home, such as when an electrical cord on an appliance becomes exposed and makes contact with the human body or when an electric source contacts water that an individual is in contact with as well, such as a hair dryer falling into a bathtub.

Common causes include:

• Exposed electrical wires
• Water on electrical appliances
• Cutting through a live cable
• Old wiring
• Faulty appliances
• Accidental contact with power outlets, power cords, or exposed parts of electrical appliances or wiring
• Flashing of electric arcs from high-voltage power lines
• Machinery or occupational-related exposures
• Young children biting or chewing on electrical cords, or poking metal objects into an electrical outlet
• Electrical weapons (such as a Taser)
• Electric shocks are occasionally caused by lightning.

The human body conducts electricity very well. That means electricity passes very easily throughout the body. Direct contact with electrical current can be deadly. While some electrical burns look minor, there still may be serious internal damage, especially to the heart, muscles, or brain.

Electric current can cause injury in four ways:

1. Cardiac arrest due to the electrical effect on the heart
2. Muscle, nerve, and tissue destruction from a current passing through the body
3. Thermal burns from contact with the electrical source
4. Falling or injury after contact with electricity

Electrical shock or burn pathophysiology

Ohm’s Law states that current is directly proportional to voltage and inversely proportional to resistance [Current (I) = Voltage (E)/Resistance (R)]. All three contribute to the pathophysiology of how electricity creates burns to the body. Contributing factors to the severity and pattern of injury include body position compared to the direction of current entering the body and duration of exposure to current.

Type of Current

Low-frequency alternating current (AC) causes more extensive injury to tissues than does high-frequency AC or direct current (DC). This is because low-frequency AC (alternating current) causes ongoing local muscle contraction (flexor muscles greater than extensor muscles) at the site of contact with the electrical source, often rendering the victim unable to let go of the offending object. In addition, alternating current (AC) injuries are much more common, as AC powers households and other buildings.

Direct current (DC) causes a single strong muscle contraction, often throwing its victim away from the energy source. The most common examples of DC (direct current) injuries include lightning strike and contact with a car battery. Of note, the risk of death and/or severity of injury from lightning strike depends on many factors, such as if the exposure was a direct lightning strike or the lightning hit something else nearby (tree/structure/ground) and then traveled to the individual’s body.

Voltage and Amperage

Electrons set in motion by the current force (voltage) may collide with each other and generate heat. The amount of heat developed by a conductor varies directly with its resistance. Power (watts) lost as a result of the current’s passage through a material provides a measure of the amount of heat generated and can be determined by Joule’s law.

• Power (P) = Voltage (E) x Current (I)
• Voltage (E) = Current (I) x Resistance (R)
• Therefore, Power (P) = Current (I)² x x Resistance (R)
• Consequently, the heat produced is proportional to the resistance and the square of the current. Commercial electric currents usually are generated with a cyclic reversal of the direction of electric pressure (voltage). Pressure in the line first pushes and then pulls electrons, resulting in alternating current. Frequency of current in hertz (Hz) or cycles per second is the number of complete cycles of positive and negative pressure in 1 second. The usual wall outlet (120 volts) provides a current with 120 reversals of the direction of flow occurring each second and is termed 60-cycle current. Frequency of alternating current can be increased to a range of millions of cycles per second. In direct current, electron travel is always in the same direction.

Burns can be classified as high or low voltage. High voltages greater than 500-1000 Volts cause deep burns and extensive deep tissue and organ damage. Low voltage exposures tend to result in lesser injury. United States households are supplied with voltages in the 110 to 220 range which causes muscle tetany and can lead to prolonged exposure to the electrical source, as the patient cannot let go. From an external source, it takes only 60 to 100 milliamps of low-frequency AC or 300 to 500 milliamps of DC to induce ventricular fibrillation. For an internal source (pacemaker), it takes less than 1 milliamp to induce ventricular fibrillation.

Resistance

Electricity, the path of least resistance; thus, most injuries occur to tissues with the least amount of resistance. Skin is the tissue with the most amount of resistance in the human body, followed by bone. Nerves, muscle, and blood have the least amount of resistance. Further reinforcing this concept is that moist tissues (muscle) have much lower resistance than dry tissues (skin). Higher skin resistance results in more diffuse burns to the skin. Lower skin resistance results in deeper burns that are more likely to involve internal organs. Whether skin is relatively dry or moist, electricity passes through the highly-resistant skin tissue and then spreads out through the underlying tissues with less resistance. Therefore, skin burns can appear mild when internal tissues and organs are severely damaged.

Electrical shock or burn prevention

• Avoid electrical hazards at home and at work. Always follow the manufacturer’s safety instructions when using electrical appliances.
• Avoid using electrical appliances while showering or wet.
• Keep children away from electrical devices, especially those that are plugged in to an electrical outlet.
• Keep electrical cords out of children’s reach.
• Never touch electrical appliances while touching faucets or cold water pipes.
• Teach children about the dangers of electricity.
• Use child safety plugs in all electrical outlets.

You can ensure electrical safety in the home by installing safety switches and making sure they are tested regularly. Always use a licensed electrician for electrical work and make sure you repair any damaged powerpoints or switches.

Never use a power tool, appliance or lead that you know is faulty or has a frayed cord. Make sure there are no electrical appliances used in wet areas or near pools.

At work, make sure all electrical equipment is regularly inspected, tested and tagged.

Electric shock or burn symptoms

The signs and symptoms of an electric shock depend on the type of current, how high the voltage is, how long the person was in contact with electricity, and their overall health.

The symptoms of an electric shock are:

• Difficulty breathing or no breathing at all
• A weak, erratic pulse or no pulse at all
• Skin burns
• Loss of consciousness
• Cardiac arrest
• Broken bones
• Heart attack (chest, arm, neck, jaw, or back pain)
• Headache
• Problems with swallowing, vision, or hearing
• Irregular heartbeat
• Muscle spasms and pain
• Numbness or tingling
• Breathing problems or lung failure
• Seizures

Electrical burn complications

Complications from electrical injuries are similar to those of other thermal burns, such as infection (which can progress to sepsis), compartment syndrome, and rhabdomyolysis (due to extensive muscle damage from internal burns). Additionally, one may have associated injuries from being thrown from the electrical source or from falling from a height (roof, bucket truck, ladder) due to the electrical shock, and these injuries (long bone fractures, spinal fractures, lacerations, pneumothorax, etc.) should be assessed and treated appropriately.

Cardiac complications can occur. One can have an arrhythmia, possibly even a fatal arrhythmia, at the time of the injury. Anyone who experiences an arrhythmia or any chest pain or other typical cardiac-related symptoms is also at risk of arrhythmia in the 24 to 48 hours following the injury. Thus these patients should be kept on a cardiac monitor at all times. Any high voltage injury should have continuous cardiac monitoring for a minimum of 8 hours [3].

A special consideration is pediatric electrical injuries that occur as the result of a child putting a cord in the mouth and biting down, causing burn injury to the corners of the mouth. These patients can be sent home if there are no other associated injuries, however, the complication in this case to warn parents about is delayed bleeding from the labial artery, which can occur about 7 days following the date of injury.

Due to the complicated nature of injury patterns with electrical injuries, anything more than a minor electrical injury should have a qualified trauma and burn center as a final disposition.

Electrical burn diagnosis

Patients with electrical burns should be examined and treated following trauma patient treatment protocols with priority to ABCDEs with a primary and secondary survey.

A thorough history should be obtained, including the source of patients electrical injury, the voltage and current type (AC or DC) of the energy source, the duration of electrical exposure, and how the injury was incurred. It is also important to obtain the patient’s cardiac history, including any history of prior arrhythmias. A head-to-toe examination should also be completed, giving particular attention to the skin, including the scalp.

The patient will usually present with burns that are indistinguishable from thermal burns, except they may have a pattern counsistent with body part in contact with the source and the ground. For example, the patient may have burns on the hands from contact with the electrical source. The electricity then travels through the tissues of their body, causing injury. Finally, the electricity causes a burn where it exits the body, commonly on the feet, which are the “ground.” These patients are specifically at risk for cardiac damage if the path of the current traversed the heart. Patients may also present with injuries from falls caused by the electrical shock, such as long bone fractures, spinal fractures, or joint dislocations (classically posterior shoulder dislocations). Of note, patients who have experienced injuries from electrical shock may have no external injuries at all, such as when a person who drops a hair dryer in the water while in a bathtub.

When documenting wounds, one should refer to areas of burns as “contact points” rather than entrance wounds and exit wounds.

Electrical burn tests

EKG, cardiac enzymes, CBC, and urinalysis (to check for myoglobin due to rhabdomyolysis) should be obtained. Any patient that was in contact with a high voltage source should have continuous cardiac monitoring during evaluation. One may also consider CT imaging of the head if the patient has altered mental status or associated head trauma from a fall or being thrown in a blast.

Electrical burn treatment

First Aid

1. If you can do so safely, turn off the electrical current. Unplug the cord, remove the fuse from the fuse box, or turn off the circuit breakers. Simply turning off an appliance may NOT stop the flow of electricity. Do NOT attempt to rescue a person near active high-voltage lines.
2. Call your local emergency number.
3. If the current can’t be turned off, use a non-conducting object, such as a broom, chair, rug, or rubber doormat to push the person away from the source of the current. Do not use a wet or metal object. If possible, stand on something dry that doesn’t conduct electricity, such as a rubber mat or folded newspapers.
4. Once the person is away from the source of electricity, check the person’s airway, breathing, and pulse. If either has stopped or seems dangerously slow or shallow, start first aid.
5. CPR should be started if the person is unconscious and you can’t feel a pulse. Perform rescue breathing on a person who is unconscious and not breathing or is breathing ineffectually.
6. If the person has a burn, remove any clothing that comes off easily and rinse the burned area in cool, running water until the pain subsides. Give first aid for burns.
7. If the person is faint, pale, or shows other signs of shock, lay him or her down, with the head slightly lower than the trunk of the body and the legs elevated, and cover him or her with a warm blanket or a coat.
8. Stay with the person until medical help arrives.
9. Electrical injury is frequently associated with explosions or falls that can cause additional severe injuries. You may not be able to notice all of them. Do not move the person’s head or neck if the spine may be injured.
10. If you are a passenger in a vehicle struck by a power line, remain in it until help arrives unless a fire has started. If necessary, try to jump out of the vehicle so that you do not maintain contact with it while also touching the ground.

DO NOT

• DO NOT get within 20 feet (6 meters) of a person who is being electrocuted by high-voltage electrical current (such as power lines) until the power is turned off.
• DO NOT touch the person with your bare hands if the body is still touching the source of electricity.
• DO NOT apply ice, butter, ointments, medicines, fluffy cotton dressings, or adhesive bandages to a burn.
• DO NOT remove dead skin or break blisters if the person has been burned.
• After the power is shut off, DO NOT move the person unless there is an ongoing risk, such as a fire or explosion.

In the emergency department, doctors will run tests to check the heart or damage to the soft tissue of the body. They may give you painkillers.

Most people with an electric shock or burn will be able to go home, unless they have heart damage that needs to be treated in hospital.

Types of Burns

Knowing the type of burn a person has can help with first-aid measures. All burns should be treated quickly to lower the temperature of the burned area and reduce damage to the skin and tissue underneath (if the burn is severe).

Burns are assessed by how seriously your skin is damaged and which layers of skin are affected.

Your skin has three layers:

• the epidermis – the outer layer of skin
• the dermis – the layer of tissue just beneath, which contains blood capillaries, nerve endings, sweat glands and hair follicles
• the subcutaneous fat, or subcutis – the deeper layer of fat and tissue.

There are four main types of burn, which tend to have a different appearance and different symptoms:

1. Superficial epidermal burn – where the epidermis is damaged; your skin will be red, slightly swollen and painful, but not blistered
2. Superficial partial-thickness (Superficial Second-Degree) burn – where the epidermis and part of the dermis are damaged; your skin will be pale pink and painful, and there may be small blisters
3. Deep Partial-Thickness (Deep Second-Degree) Burn – where the epidermis and the dermis are damaged: this type of burn makes your skin turn red and blotchy; your skin may be dry or moist, and become swollen and blistered, and it may be very painful or painless
4. Full thickness burn – where all three layers of skin (the epidermis, dermis and subcutis) are damaged; the skin is often burnt away and the tissue underneath may appear pale or blackened, while the remaining skin will be dry and white, brown or black with no blisters, and the texture of the skin may also be leathery or waxy.
5. Fourth-Degree Burns: Fourth-degree burns destroy all skin layers and extend into muscle, tendon, or bone ⁴.

Figure 1. Skin structure

First-Degree (Superficial) Burns

Superficial (shallow) burns are the mildest type of burns. They’re limited to the top layer of skin:

• Signs and symptoms: These burns cause redness, pain, and minor swelling. The skin is dry without blisters.
• Healing time: Healing time is about 3–6 days; the superficial skin layer over the burn may peel off in 1 or 2 days.

Second-Degree (Partial Thickness) Burns

These burns are more serious and involve the top layer of skin and part of the layer below it. The burn site appears red, blistered, and may be swollen and painful.

• Signs and symptoms: The burned area is red and blistered, and can swell and be painful. The blisters sometimes break open and the area is wet looking with a bright pink to cherry red color.
• Healing time: Healing time varies depending on the severity of the burn. It can take up to 3 weeks or longer.

Full Thickness Burns

Full thickness burns also called third-degree burns or fourth-degree burns, are the most serious type of burn. They involve all layers of the skin and the nerve endings there, and may go into underlying tissue.

• Signs and symptoms: The surface appears dry and can look waxy white, leathery, brown, or charred. There may be little or no pain or the area may feel numb at first because of nerve damage.
• Healing time: Healing time depends on the severity of the burn. Most need to be treated with skin grafts, in which healthy skin is taken from another part of the body and surgically placed over the burn wound to help the area heal.

1. Gentges J, Schieche C. Electrical injuries in the emergency department: an evidence-based review. Emerg Med Pract. 2018 Nov;20(11):1-20.
2. Bounds EJ, Kok SJ. Electrical Burns. [Updated 2019 Jan 23]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2019 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK519514
3. Brandão C, Vaz M, Brito IM, Ferreira B, Meireles R, Ramos S, Cabral L. Electrical burns: a retrospective analysis over a 10-year period. Ann Burns Fire Disasters. 2017 Dec 31;30(4):268-271.
4. U.S. Department of Health and Human Services. Burn triage and treatment: thermal injuries. https://www.remm.nlm.gov/burns.htm