<Things you should know> Correct knowledge about burns (1) Explanation of types and symptoms of burns What is a burn? Causes (mechanisms) of burns Burn level and symptoms Types of burns and their complications Burns are one of the most common injuries we all experience. Most people have likely experienced a minor burn. However, some burns can be life-threatening, and others are caused by chemicals. Burns come in a wide variety of severity and types.Here, under the supervision of a dermatologist, we will introduce the types and symptoms of burns. What is a burn? Accidentally touching a pot while cooking, spilling a hot drink, touching your forehead with a hair iron... Burns are a common type of injury. First, let's review the definitions of burns, their scars, and similar injuries. burn Burns, medically known as "thermal injuries," are injuries that result from contact with high-temperature gases, liquids, or solids, causing damage to the skin or mucous membranes. Regardless of severity, they are one of the most common injuries. The most frequent age group affected is young children under 10 years old.Symptoms vary depending on the extent and depth of the injury. Mild cases may cause a slight stinging pain, but heal within a few days even without treatment. Generally, no scarring occurs. However, severe cases may require skin grafting surgery or comprehensive management to prevent secondary damage such as organ failure. Low-temperature burns This type of burn is medically known as a "low-temperature burn." While contact with high-temperature gases, liquids, or solids causes burns (thermal burns) in a short time, prolonged exposure to lower-temperature stimuli (40-55°C) results in a low-temperature burn. Specific causes include prolonged application of hot water bottles or heat packs to the same area. It is particularly common in young children and the elderly, who have thin skin. It is also frequently seen in diabetic patients with peripheral nerve sensory impairment. frostbite While burns occur when exposed to high-temperature gases, liquids, or solids, frostbite occurs when skin tissue suffers peripheral circulatory impairment due to sub-zero temperatures.In mild cases, the skin may become pale or purple, and sensation may be dulled. In severe cases, blisters may form, and vascular damage (blood stasis or thrombus formation) may occur, preventing proper blood flow to the extremities and potentially leading to necrosis.While frostbite occurs when exposed to sub-zero temperatures, chilblains are caused by temperatures above freezing (4-5 degrees Celsius, with a daily temperature range of 10 degrees Celsius or more). Chilblains are what is commonly known as "frostbite," and are characterized by itchy red patches and blisters. They are more common in early and late winter than during the coldest part of the year. burn scars Scars left by burns that occur in areas deeper than the dermis are medically referred to as "scars." These scars can be raised or depressed, and may result in hyperpigmentation or depigmentation. The way scars remain varies greatly depending on the severity of the burn, the treatment method, and the patient's constitution.In contrast, burns that occur to a depth of the superficial dermis do not result in scarring, but rather in hyperpigmentation. Causes (mechanisms) of burns Our skin has a barrier function that protects it from stimuli such as heat and cold.For example, when your skin darkens from sun exposure, it's due to the body's barrier function. Melanin is produced to protect against harmful ultraviolet rays penetrating deep into the body.However, this barrier function also has its limits. When exposed to a certain level of stimuli, or in the case of burns, high-temperature gases, liquids, or solids, the barrier function breaks down. This then leads to damage such as burns (or low-temperature burns). When skin comes into contact with a hot substance, cellular function is disrupted. This leads to the formation of blood clots in nearby blood vessels and increased vascular permeability (the movement of water and nutrients between blood vessels and surrounding cells). This is what causes edema.The progression of symptoms afterward varies depending on the extent and depth of the burn, which will be explained in more detail later. Burn level and symptoms The severity of a burn is diagnosed based on both its depth and size. Since the symptoms and treatment methods vary greatly depending on these factors, it's essential to first determine the extent of the burn. Symptoms of burns by depth Even with the same type of burn, the symptoms vary depending on the severity. Burn depth can be measured by "temperature x time," and burns are classified into first-degree, second-degree (which includes superficial second-degree and deep second-degree burns), and third-degree burns. Let's first look at the symptoms that can be seen at each degree of burn depth. First-degree burns (when the epidermis is damaged) Many people have likely experienced a minor burn at some point. While it may cause redness, swelling, and a burning sensation in the affected area, these symptoms usually improve within a few days. It also doesn't leave scars. Superficial second-degree burns (damage to the epidermis and part of the dermis) Compared to Grade I, erythema and edema are clearly visible, and red blisters form within 24 hours of the injury. These blisters may rupture, resulting in erosions (ulceration). Pain is also a characteristic feature. Complete recovery takes 2-3 weeks, but no scars remain. Deep second-degree burns (damage extending from the epidermis to the deep dermis) Unlike superficial second-degree burns, when the dermis is damaged deeply, milky white blisters form. Also, sensation is dulled, so there is usually little to no pain. Complete healing takes 3 to 4 weeks, but the blisters may rupture and ulcerate, or the condition may worsen and progress to third-degree burns. Furthermore, scars may remain even after complete healing. Third-degree burns (damage to the entire skin layer and deeper) In third-degree burns, the surface of the affected area is covered with necrotic tissue, and the skin becomes white, yellowish-brown, or black. Sensation is completely lost, and pain cannot be felt. Spontaneous healing is possible if epidermal proliferation occurs around the affected area, but in many cases, skin grafting surgery is necessary. Severe scarring remains even after complete recovery. How to determine the extent of a burn Above, we looked at how to measure the depth of a burn, but there is also a method for measuring its extent. The Rule of 9 This is a rule for calculating the extent of burns in adults. The whole body is divided into nine major sections (head, left and right upper limbs, front and back of the trunk, left and right lower limbs, and genitals), and the assigned values for each section are added together to make a simple diagnosis of the extent of burns throughout the body. For example, if both arms are burned, it is calculated that 18% of the body has been damaged by heat. The Rule of 5 While the Rule of Nine is used for adults, the Rule of Five is used to calculate the extent of burns in children and infants. The concept is the same as the Rule of Nine, but the values assigned to each body part are different. For example, if both arms are burned, the burn area is 18% for adults, while it is 20% for children and infants. Burn severity classification Burns are classified into three categories based on severity: mild, moderate, and severe. The criteria for each category are as follows: Mild If less than 15% of the burns are second-degree burns, or less than 2% are third-degree burns, outpatient treatment at a medical facility will be necessary. moderate If 15-30% of the burns are second-degree, or less than 10% are third-degree, hospitalization at a general hospital will be necessary. severe Severe burns are defined as those involving 30% or more of the body being second-degree, or 10% or more of the body being third-degree. Other severe burns include those affecting the face, limbs, or airways, as well as soft tissue damage and fractures. These burns require hospitalization at a general hospital. Types of burns and their complications Heat is not the only cause of burns. Furthermore, the potential complications vary depending on the location and severity of the injury.Here, we will look at the types of burns and their complications. Types of burns Burns can be classified into several types depending on their cause. In addition to the thermal burns, low-temperature burns, and frostbite (and chilblains) mentioned at the beginning, there are several other injuries that are classified as burns. Some of these injuries are classified as burns but are not caused by heat.Now, let's discuss the different types of burns in detail. Electric shock injury Electric burns are caused by electricity passing through the body. There are two types of electric shock burns: one is caused by an electric spark, which damages the surface of the body. In this case, the level of damage is relatively mild, but if the clothing being worn catches fire, the area of injury can spread.Another type of burn involves damage to internal tissues caused by an electric current. Various tissues, such as nerves, muscles, and blood vessels, are damaged by the heat of the electric current, resulting in extremely severe burns. Depending on the strength of the current and other conditions, it can even cause cardiac arrest at the time of injury. Chemical burns Skin damage caused by the following chemicals. Although not caused by heat, it is classified as a type of burn because it presents symptoms similar to burns. ■ Acid Sulfuric acid, nitric acid, hydrochloric acid, acetic acid, etc.■ Alkaline Sodium hydroxide, potassium hydroxide, ammonia, etc.■ Corrosive fragrance Phenol, cresol, benzene, etc.■ Fat compounds Kerosene, petroleum benzine, formaldehyde, etc.■ Metals and other compounds Sodium, calcium oxide, sodium carbonate, etc.■ Nonmetals and other compounds Phosphorus and its compounds, hydrogen sulfide, sulfur chloride, etc. Symptoms vary depending on the causative substance, but in the case of acids, blistering may occur, followed by necrosis of skin tissue and severe pain. Alkalis have the property of dissolving proteins, and although they cause less pain than acids, they often result in deeper damage. Radiation burns (radiation dermatitis) Radiation-induced skin damage is divided into acute radiation dermatitis, which occurs immediately after exposure, and chronic radiation dermatitis, which occurs six months or more later. In the case of acute radiation dermatitis, abnormalities such as painful erythema, edema, and sores may appear on the skin. It usually heals within a few weeks to a few months, but hair will not grow back in the affected area, and sequelae such as dilated capillaries and pigment abnormalities may remain.In cases of chronic radiation dermatitis, the condition progresses in the following order: the "atrophic stage" where skin atrophy and hair loss occur; the "keratinization stage" where hyperkeratosis progresses; the "ulcerative stage" where severe ulcers that are difficult to heal develop; and the "cancerous stage" where cancer develops in the squamous cells and basal cells. It takes about 15 to 20 years to reach the cancerous stage. Airway burns Airway burns are burns that occur in the respiratory tract, such as from inhaling high-temperature gases. If you experience any of the following symptoms, you may have an airway burn. ■ Swelling may be observed in the mouth or throat. ■ Soot is clinging to the inside of the mouth and throat. ■ They are coughing or making wheezing noises. ■ Nose hairs are burnt If burns cause the upper airway to become blocked, leading to difficulty breathing, a ventilator will be used to manage the respiratory system. Hyperthermic erythema While it may not result in a low-temperature burn, prolonged and repeated exposure to heat can cause erythema (redness). This is called thermal erythema, and it is caused by the dilation and congestion of blood vessels in the area exposed to heat, leading to pigmentation by melanin and hemosiderin. It is often caused by prolonged exposure to electric heaters. Complications of burns The danger of burns isn't limited to skin damage. Burns can also trigger a variety of complications. Let's take a look at some of the main types of complications. Dehydration, hypoproteinemia When you suffer a burn, a large amount of exudate containing water and protein is secreted from the wound. If this amount becomes too large, it can lead to dehydration and hypoproteinemia. Managing fluid and protein intake is essential. Low-volume shock When you suffer a burn, vascular permeability increases, which reduces the amount of blood circulating in your body. This increases the risk of your body going into shock. Shock symptoms can include fever, convulsions, and vomiting. For this reason, in cases of severe burns, fluid replacement therapy is used to manage shock. Organ damage Burns can cause tissue edema, which can affect various organs. Specifically, these include the following: ■ Airway obstruction ■ Liver congestion, cell degeneration ■ Cerebral edema, softening ■ Myocardial degeneration Even if a person survives immediately after being burned, these organ damages can lead to death. Furthermore, the skin's natural barrier function and various immune functions are also impaired. infectious disease Severe burns can lead to infections from Staphylococcus aureus, MRSA, Pseudomonas aeruginosa, and other bacteria at the burn site. Furthermore, it's important to be aware of respiratory and urinary tract infections, as well as sepsis, which can cause multiple organ failure.In addition, with chemical burns, if chemicals remain on the skin, the mucous membranes can absorb them, potentially causing poisoning symptoms. Supervised by: Dr. Tomoko Fujimoto, Director of Ikebukuro Nishiguchi Fukuro Dermatology ClinicAfter graduating from the Faculty of Medicine, Hamamatsu University School of Medicine, he joined the Department of Dermatology at Tokyo Medical and Dental University. Subsequently, he served as an assistant professor at the same university, and as chief of dermatology at Tama Southern Regional Hospital and Tokyo Metropolitan Otsuka Hospital before opening Ikebukuro Nishiguchi Fukuro Dermatology Clinic. He is a certified dermatologist by the Japanese Dermatological Association. We take care to post accurate information,Please point out any incorrect information. Please submit any comments regarding medical information here. Return to the list of guides categorized by health symptoms.