An electrical burn is a unique and often deceptive injury resulting from the body’s exposure to electrical energy. Unlike a simple thermal burn caused by fire or a hot object, electricity can travel through the body’s tissues, generating heat and causing extensive damage beneath the skin that is not visible on the surface. Understanding these distinct injury mechanisms is important for recognizing the true severity of the injury and seeking appropriate medical care.
Mechanisms of Electrical Injury
Electrical energy causes injury through three primary mechanisms. The severity of the injury is determined by factors including voltage, duration of contact, and the body’s resistance along the current’s path. Higher voltage or longer exposure time increases the potential for significant damage.
Tissues possess varying levels of electrical resistance; bone is the most resistant, while nerves and blood vessels offer the least. When current flows through the body, it generates heat—known as Joule heating—which causes thermal destruction along the path of least resistance. This internal heating, combined with external effects, leads to the three main types of electrical burns.
Flash Burns: Surface Thermal Damage
Flash burns result from the intense heat and light produced by an electrical arc. These injuries occur when a nearby electrical fault generates a high-temperature flash without the current passing through the victim’s body. The damage is superficial, similar to a severe sunburn or a first-degree thermal burn, and typically affects exposed skin.
Although often the least severe in terms of internal injury, flash burns can be extensive and painful. A specific risk is to the eyes, where intense light and ultraviolet energy can cause a painful injury to the cornea, known as welder’s flash or photokeratitis.
Arc Burns: High-Intensity Heat Exposure
Arc burns occur when an electrical current jumps from a source to the body, or from one conductor to another, through the air, creating a sustained electrical arc. This phenomenon generates temperatures that can reach as high as 7,200 degrees Fahrenheit, hot enough to vaporize metal and cause deep, localized thermal injury. The arc does not require direct physical contact with the source, as the current ionizes the air to bridge the gap.
The extreme heat causes deep, third-degree thermal destruction to the skin and underlying soft tissue where the arc strikes. The heat can also instantly ignite clothing, leading to secondary flame burns. The explosive pressure wave accompanying the arc, known as an arc blast, may also cause mechanical injuries like concussions or fractured bones.
Contact Burns: Internal Tissue Pathway
Contact burns, often called “true” electrical injuries, are the most dangerous type because the body becomes part of the electrical circuit. This injury occurs when a person touches a live source, allowing current to enter at one point and exit at another. The external entry and exit wounds may appear deceptively small, often looking like small, charred areas of skin.
The primary danger is the invisible damage caused by the current traveling through low-resistance internal structures like nerves, blood vessels, and muscle tissue. Internal heat generation destroys these tissues, leading to widespread cell death and necrosis far from the surface burns. Damage to muscle tissue (rhabdomyolysis) releases cell contents into the bloodstream, which can overwhelm the kidneys and lead to acute kidney failure.
If the current passes through the chest, it can disrupt the heart’s electrical system, causing immediate or delayed cardiac arrhythmias. A current pathway through the brain or spinal cord can result in severe neurological damage, including seizures, respiratory arrest, and long-term nerve dysfunction. A seemingly minor external injury can mask a life-threatening internal crisis requiring extensive medical intervention.
Immediate Safety and First Steps
The safety of the rescuer is the first priority; never touch a person still in contact with the electrical source. The power source must be disconnected immediately by turning off the main circuit breaker or unplugging the appliance. If the power cannot be turned off, use a non-conducting object, such as a dry wooden stick or cardboard, to separate the victim from the source.
Once the victim is safe, check for breathing and a pulse, and begin cardiopulmonary resuscitation (CPR) if necessary. Cover any burned areas loosely with a sterile gauze bandage or a clean cloth. Seek emergency medical attention for any electrical injury, regardless of how minor the surface burn appears. Even a brief shock can cause delayed internal issues, such as cardiac irregularities or kidney damage, requiring immediate medical evaluation.