Sunburn is a form of radiation burning that affects living tissue, such as skin, resulting from excessive UV radiation, generally from the sun. Common symptoms in humans and other animals include redness or redness that feel hot to the touch, pain, general fatigue, and lightheadedness. Excess UV radiation can be life-threatening in extreme cases. Excessive UV radiation is the leading cause of non-malignant skin tumors.
Sunburn is an inflammatory response in the skin that is triggered by DNA damage directly by UV radiation. When the DNA of the skin cells is too damaged by UV radiation, cell type I death is triggered and the skin is replaced.
Solar protection measures including sunscreen and sun protection are widely accepted to prevent sunburn and certain types of skin cancer. Specific populations including children are particularly vulnerable to sunburn and protective measures should be used.
Video Sunburn
Signs and symptoms
Usually, there is an initial redness (erythema), followed by varying degrees of pain, proportionate in the severity of both duration and intensity of exposure.
Other symptoms may include blisters, swelling (edema), pruritus (itching), peeling skin, rash, nausea, fever, chills, and fainting (syncope). Also, a small amount of heat is removed from the burn, caused by blood concentration in the healing process, giving a warm feeling to the affected area. Sunburns can be classified as superficial, or partial burns. Blistering is a second degree sunburn sign.
Variations
Mild sunburns usually cause no more than a slight redness and pain in the affected area. In more serious cases, the heat can occur. Extreme sunburns can be painful to the point of weakness and may require hospitalization.
Duration
Sunburn can occur in less than 15 minutes, and in seconds when exposed to unprotected welding arcs or other strong ultraviolet light sources. However, the danger posed is often not immediately apparent.
After exposure, the skin may turn red within 30 minutes but most often takes 2 to 6 hours. Pain is usually the most extreme 6 to 48 hours after exposure. Burns continue to develop for 1 to 3 days, sometimes followed by exfoliation in 3 to 8 days. Some exfoliation and itching may persist for several weeks.
Skin cancer
Ultraviolet radiation causes sunburn and increases the risk of three types of skin cancer: melanoma, basal cell carcinoma and squamous cell carcinoma. The biggest concern is that the risk of melanoma increases in a dose-dependent manner with the number of lifelong cumulative episodes from a sunburn. It is estimated that more than 1/3 of melanoma in the United States and Australia can be prevented by the use of regular sunscreen.
Maps Sunburn
Cause
Biological
Sunburn is caused by UV radiation, either from the sun or from artificial sources, such as tanning lamps, welding arcs, or ultraviolet germ radiation. It is the body's reaction to direct DNA damage from UVB rays. This damage is primarily the formation of thymine dimers. The damage is recognized by the body, which then triggers several defense mechanisms, including DNA repair to restore damage, apoptosis and exfoliation to remove damaged skin cells that can not be repaired, and increase melanin production to prevent future damage. Melanin easily absorbs UV light, acting as a photoprotectant. By preventing UV photons from interfering with chemical bonds, melanin inhibits both direct changes in DNA and the formation of free radicals, resulting in indirect DNA damage.
Sunburn causes inflammatory processes, including prostanoid production and bradykinin. This chemical compound increases heat sensitivity by reducing the thermal receptor activation threshold (TRPV1) from 109 ° F (43 ° C) to 85 ° F (29 ° C). Pain can be caused by an overproduction of a protein called CXCL5, which activates nerve fibers.
This type of skin determines the ease of sunburn. In general, people with lighter skin tones and limited capacity to develop the skin after exposure to UV radiation have a greater risk of sunburn. The Fitzpatrick's Skin phototypes classification describes the normal variation of skin's response to UV radiation. People with Type I skin have the greatest capacity for sunburn and Type VI has the least capacity to burn. However, all skin types can develop sunburn.
Fitzpatrick's skin photographer:
- Type I: Pale white, flammable, not sunbathing
- Type II: Whites, flammable, without difficulty
- Type III: White, flammable but easily dull
- Type IV: Light brown/olive skin, hardly burning, easy to dull
- Type V: Brown skin, usually not burning, easy to dull
- Type VI: Blacks, very unlikely to burn, become darker with UV radiation exposure
Age also affects how the skin reacts to the sun. Children younger than six and adults older than sixty are more sensitive to sunlight.
There are certain genetic conditions, such as xeroderma pigmentosum, which increases a person's susceptibility to sunburn and subsequent skin cancer. This condition involves defects in DNA repair mechanisms which in turn decreases the ability to repair DNA that has been damaged by UV radiation.
Drugs
The risk of sunburn may be enhanced by pharmaceutical products that make the user sensitive to UV radiation. Certain antibiotics, oral contraceptives, and sedatives have this effect.
UV Intensity
The UV index shows the risk of getting sunburn at a particular time and location. Contributing factors include:
- Time of day. In most locations, the most intense sunlight is between 10 am to 4 pm summer time.
- Cloud cover. UV blocked in part by cloud; but even on a cloudy day, a significant percentage of UV radiation that damages the sun can pass through the clouds.
- Proximity to reflective surfaces, such as water, sand, concrete, snow, and ice. All these reflect sunlight and can cause sunburn.
- This year's season. The position of the sun in late spring and early summer may cause a more severe sunburn.
- Altitude. At higher altitudes it is easier to burn, because there is less of the earth's atmosphere to block out the sun. UV exposure increases by about 4% for every 305 feet (305 m) elevation.
- Distance to the equator (latitude). Between the polar regions and the tropics, the closer to the equator, the more direct sunlight penetrates the atmosphere for a year. For example, the southern United States gets fifty percent more sunshine than the northern United States.
Due to the variations in the intensity of UV radiation passing through the atmosphere, the risk of sunburn increases with proximity to tropical latitudes, located between 23.5 Â ° north and south latitude. All others are the same (eg Cloud cover, ozone layer, terrain, etc.), For a full year, any location in the tropics or polar regions receives equal amounts of UV radiation. In temperate zones between 23.5 Â ° and 66.5 Â °, UV radiation varies substantially by latitude and season. The higher the latitude, the lower the intensity of UV light. Intensity in the northern hemisphere is greatest during May, June and July - and in the southern hemisphere, November, December and January. In minute by minute, the amount of UV radiation depends on the angle of the sun. This is easily determined by the ratio of the height of any object to its shadow size. The biggest risk is in the daytime sun, when the shadow is at their minimum and solar radiation passes most directly through the atmosphere. Regardless of one's latitude (assuming no other variables), the same shadow length means the same amount of UV radiation.
The skin and eyes are most sensitive to UV damage at wavelengths of 265-275 nm, which is in the lower UVC band that is almost never found except from artificial sources such as welding arcs. Most of the sunburn is caused by longer wavelengths, because more sunlight takes place in the sun on the ground.
Ozone depletion
In the last few decades, the incidence and severity of sunburn have increased worldwide, in part because of chemical damage to the atmospheric ozone layer. Between the 1970s and 2000s, the average stratospheric ozone decreased by about 4%, accounting for an increase of about 4% to the average UV intensity on the Earth's surface. Ozone depletion and seasonal "ozone holes" have caused far greater changes in some locations, especially in the southern hemisphere.
Tanning
Suntans, which naturally develop in some individuals as a mechanism of protection against the sun, are seen by most in the Western world as desired. This has led to an overall increase in UV radiation exposure from both natural sun and tanning lamps. Suntans can provide simple sun protection factor (SPF) of 3, which means that the tan will tolerate up to three times the exposure of UV rays as pale skin.
Sunburns associated with indoor tanning can be severe and are the most common indoor-tanning injuries that are treated in the US emergency department.
The World Health Organization, the American Academy of Dermatology, and the skin cancer foundation recommends avoiding artificial UV sources such as tanning beds, and do not recommend suntan as a form of sun protection.
Diagnosis
Differential Diagnosis:
The differential diagnosis of sunburn includes other skin pathologies caused by UV radiation including photoallergic reactions, phototoxic reactions to topical or systemic drugs, and other dermatological disorders exacerbated by sun exposure. Considerations for diagnosis include duration and intensity of UV exposure, topical or systemic drug use, history of dermatological disease, and nutritional status.
- Phototoxic reactions: Non-immunological responses to sunlight interacting with certain drugs and chemicals in skin that resemble excessive sunburn. Common drugs that can cause phototoxic reactions include amiodarone, dacarbazine, fluoroquinolones, 5-fluorouracil, furosemide, nalidixic acid, phenothiazine, psoralens, retinoids, sulfonamides, sulfonylureas, tetracyclines, thiazides, and vinblastin.
- Photoallergy reactions: Unusual immunological responses to sunlight interacting with certain drugs and chemicals in the skin. When in a state excited by UVR, these drugs and chemicals form free radicals that react to form functional antigens and induce Type IV hypersensitivity reactions. These drugs include 6-methylcoumarin, aminobenzoic acid and esters, chlorpromazine, promethazine, diclofenac, sulfonamides, and sulfonylureas. Unlike photoxic reactions similar to excessive sunburns, photoallergic reactions can cause intense itching and can cause skin thickening.
- Phytophotodermatitis: UV radiation induces skin inflammation after contact with certain plants (including limes, celery, and pasture grasses). Causes pain, redness, and skin blister in the distribution of plant exposure.
- Polymorphic light eruption: Repeated abnormal reactions to UVR. Can be present in various ways including pink-to-red lumps, blisters, plaque and urticaria.
- Solar urticaria: Whey induced by UVR rays that occur within minutes of exposure and fade within hours.
- Other skin diseases are exacerbated by sunlight: Some dermatological conditions can increase severity with UVR exposure. These include systemic lupus erythematosus (SLE), dermatomyositis, acne, atopic dermatitis, and rosacea.
Prevention
Skin
The most effective way to prevent sunburn is to reduce the amount of UV radiation that reaches the skin. The World Health Organization, the American Academy of Dermatology, and Skin Cancer Foundation recommend the following steps to prevent excessive UV exposure and skin cancer:
- Limit sun exposure between 10 am and 4 pm, when UV light is the strongest
- Find shadows when UV rays are strongest
- Wear sun-protective clothing including wide-brimmed caps, sunglasses, and loose tight woven garments
- Use sunscreen
- Avoid tanning beds and artificial UV exposure
UV Intensity:
Sunlight power is published in many locations as the UV Index. Sunlight is generally strongest when the sun is near the highest point in the sky. Due to the time zones and summer time, this is not always at 12 noon, but often one to two hours later. Finding shade including using an umbrella and canopy can reduce the amount of UV exposure, but does not block any UV rays. WHO recommends following shadow rules: "Watch your shadow - Short shadows, look for shadows!"
Sunscreen:
Commercial preparations are available that block UV rays, known as sunblocks or sunblocks. They have a sun protection factor rating (SPF), based on the ability of sunscreen to suppress sunburn: The higher the SPF rating, the lower the amount of direct DNA damage. The protection factor expressed is true only if 2 LL of sunscreen is applied per square cm of exposed skin. This translates into about 28 mL (1 oz) to cover the entire body of the adult male, which is much more than many people use in practice. Sunscreens serve as chemicals such as oxybenzone and dioxybenzone that absorb UV radiation (chemical sunscreen) or opaque materials such as zinc oxide or titanium oxide to physically block UV radiation (physical sunscreen). Chemical and mineral sunscreens vary in the wavelength of blocked UV radiation. A broad-spectrum sunscreen contains filters that protect against UVA and UVB radiation. Although UVA radiation does not primarily cause sunburn, it does not contribute to skin aging and an increased risk of skin cancer.
Sunscreen is effective and thus recommended to prevent melanoma and squamous cell carcinoma. There is little evidence that it is effective in preventing basal cell carcinoma. The special use of sunscreen usually does not cause vitamin D deficiency, but widespread use is possible.
Recommended use
Studies have shown that the best sunscreen protection is achieved by application 15 to 30 minutes before exposure, followed by one re-application 15 to 30 minutes after exposure begins. Further complications are needed only after activities such as swimming, sweating, and rubbing. It varies based on the indication and protection shown on the label - from 80 minutes in water up to several hours, depending on the selected product. The American Academy of Dermatology recommends the following criteria in selecting sunscreen:
- Broad spectrum: protects against UVA and UVB rays
- SPF 30 or higher
- Waterproof: sunscreen is classified as waterproof by time, either 40 minutes, 80 minutes, or is not waterproof
Eyes
The eye is also sensitive to exposure to sunlight at the same UV wavelength as the skin; snow blindness is basically the sunburn of the cornea. Sunglasses or use by spectacles-wearing glasses that block UV rays reduce harmful radiation. UV rays have been implicated in the development of age-related macular degeneration, pterygium and cataracts. A concentrated group of melanin, commonly known as spots, is often found in irises.
Diet
Food factors affect susceptibility to sunburn, recovery from sunburn, and risk of secondary complications from sunburn. Some dietary antioxidants, including essential vitamins, have been shown to have some effectiveness to protect against sunburn and skin damage associated with ultraviolet radiation, both in human and animal studies. Supplementation with Vitamin C and Vitamin E was demonstrated in one study to reduce the amount of sunburn after a controlled amount of UV exposure. A review of the scientific literature until 2007 found that beta-carotene supplements (Vitamin A) had a protective effect against sunburn, but the effect was only proven in the long run, with supplementation studies for periods less than 10 weeks in duration failing to show any effect. There is also evidence that common food may have the ability to protect against sunburn if taken for a period of time before exposure.
Protect Children:
Infants and children are particularly vulnerable to UV damage that increases the risk of melanoma and non-melanoma skin cancer in the future. Children should not burn sunshine at any age and protective measures can ensure the risk of future skin cancer decreases.
- Infants 0-6 months: Children under 6 months generally have skin that is too sensitive for sunscreen and protective measures should focus on avoiding excess UV exposure by using window nets, wide-brimmed hats, lose clothes that cover the skin, and reduce the UV Display between 10 am to 4 pm.
- Infants 6-12 months: Sunscreen can be safely used in this baby age. It is recommended to apply a broad spectrum of sunscreen SPF30 to an open area and avoid excessive exposure to UV light by using a wide-brimmed hat and protective clothing.
- Pre-school News and Preschools: Apply SPF 30 broad-spectrum sunscreen to the exposed area, use a wide-brimmed hat and sunglasses, avoid the peak peak UV hours at 10 am - 4 pm and find a shade. Sunscreen clothing with an SPF rating may also provide additional protection.
Created UV view:
WHO recommends that artificial UV exposure including tanning beds should be avoided as there is no established dose of safety. When a person is exposed to a UV-made source of work, special protective clothing (eg, welding helmet/shield) should be worn. Such sources can produce UVC, a highly carcinogenic UV wave that is not normally present in normal sunlight, which has been filtered by the atmosphere.
Treatment
The main measure is to avoid further exposure to the sun. The best treatment for most sunburns is time. Most sunburns heal completely within a few weeks.
The American Academy of Dermatology recommends the following for the treatment of sunburn:
- To relieve pain, bathing or bathing with frequent bathing.
- Use a soothing moisturizer that contains aloe or soybean. Free-bought hydrocortisone cream can also be used in painful areas, but avoid cream ending in "caine" as this can be more irritating.
- Anti-inflammatory drugs such as ibuprofen or aspirin can help with pain.
- Stay hydrated and drink extra water.
- Do not blister pop on sunburn. Instead, let them heal themselves.
- Protect sunburned skin with loose clothing when going out to prevent further damage.
Non-steroidal anti-inflammatory drugs (such as ibuprofen or naproxen), and aspirin can reduce redness and pain. Local anesthetics such as benzocaine, however, are contraindicated. Schwellnus et al. states that topical steroids (such as hydrocortisone creams) do not help with sunburns, although the American Academy of Dermatology says they can be used in diseased areas. While lidocaine creams are often used as a treatment of sunburn, there is little evidence for the effectiveness of such use.
Home treatments that can help with discomfort include using a cold and wet cloth in a sunburned area. Applying a soothing lotion containing aloe vera to the sunburn area is supported by one review. Others have found aloe vera has no effect. Aloe vera does not have the ability to protect people from sunburn. Other treatments include using moisturizers containing soy.
Sunscreen draws fluid to the surface of the skin and away from other body parts. Drinking extra water when you are sunburn helps to prevent dehydration.
References
External links
- Sunburn at Curlie (based on DMOZ)
Source of the article : Wikipedia
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