Sunburn

Definition

A sunburn is an inflammation or blistering of the skin caused by overexposure to the sun.

Description

Sunburn is caused by excessive exposure to the ultraviolet (UV) rays of the sun. There are two types of ultraviolet rays, UVA and UVB. UVA rays penetrate the skin deeply and can cause melanoma in susceptible people. UVB rays, which don't penetrate as deeply, cause sunburn and wrinkling. Most UVB rays are absorbed by sunscreens, but only about half the UVA rays are absorbed.

Skin cancer from sun overexposure is a serious health problem in the United States, affecting almost one million Americans each year. One person out of 87 will develop malignant melanoma, the most serious type of skin cancer , and 7,300 of them will die each year. The Environmental Protection Agency (EPA) reported in 2000 that the rate of malignant melanoma is rising faster in the United States than the rates of all other preventable cancers except lung cancer . One reason for this high rate is the popular belief that suntanned skin is healthy and attractive. Many people spend more time in the sun than is good for their skin trying to achieve a fashionable tan.

People with fair skin are most susceptible to sunburn, because their skin produces only small amounts of the protective black or dark brown pigment called melanin. However, people of any race can get sunburned if they do not protect their skin against overexposure. People trying to get a tan too quickly in strong sunlight are also more vulnerable to sunburn.

Repeated sun overexposure and burning can prematurely age the skin, causing yellowish, wrinkled skin. Overexposure, especially a serious burn in childhood, can increase the risk of skin cancer.

Causes & symptoms

The ultraviolet rays in sunlight destroy cells in the outer layer of the skin, damaging tiny blood vessels underneath. When the skin is burned, the blood vessels dilate and leak fluid. Cells stop making protein. Their DNA is damaged by the ultraviolet rays. Repeated DNA damage can lead to cancer.

When the sun burns the skin, it triggers immune defenses which identify the burned skin as foreign. At the same time, the sun transforms a substance on the skin which interferes with this immune response. While this substance keeps the immune system from attacking a person's own skin, it also means that any malignant cells in the skin will be able to grow freely.

Sunburn causes skin to turn red and blister. Several days later, the dead skin cells peel off. In severe cases, the burn may occur with sunstroke (vomiting, fever , and fainting).

While overexposure to the sun is harmful, even fatal, no exposure means the body can't manufacture vitamin D , which is the only vitamin whose biologically active form is a hormone. Vitamin D is produced in the skin from the energy of the sun's UV rays. People at risk for vitamin D deficiency include alcoholics, non-milk drinkers, and those who do not receive much sunlight—especially those who live in regions that get little natural light. Dr. Sheldon Saul Hendles says that as more people use sunscreens and decrease exposure to the sun, they should make sure to have adequate dietary and supplementary sources of vitamin D. Sunscreen prevents the synthesis of the vitamin.

Diagnosis

Symptoms of sunburn may not appear until several hours after exposure. A deep pink skin color accompanied by a sensation of heat and burning indicates a mild sunburn. A red color with visible clothing lines, burning, itching , and stinging indicates a moderate burn. Bright red skin with blisters , fever, chills , and nausea indicates severe burn and medical help should be sought quickly.

Treatment

Over-the-counter preparations containing aloe (Aloe barbadensis ) are an effective treatment for sunburn, easing pain and inflammation while also relieving dryness of the skin. A variety of topical herbal remedies applied as lotions, poultices, or compresses may also help relieve the effects of sunburn. Calendula (Calendula officinalis ) is one of the most frequently recommended to reduce inflammation.

Other natural remedies include:

• Applying compresses dipped in cold water, one part skim milk mixed with four parts cold water, aluminum acetate antiseptic powder mixed with water, witch hazel , white vinegar, or baking soda mixed with water.
• Making a paste out of cornstarch and water, and applying directed to affected areas.
• Placing thin, cold slices of raw cucumber, potato, or apple on the burned areas.
• Making a soothing solution by boiling lettuce in water, strain, cool the water for several hours in the refrigerator, then use cotton balls to pat the liquid onto the skin.
• Applying tea bags soaked in cold water to burned eyelids.
• Soothing the burn with cool yogurt, then rinsing with a cold shower.

Another natural remedy that has been proposed for treating sunburn is gingko biloba extract. A Turkish study published in 2002 reported that gingko biloba appears to heal sunburned skin after exposure as well as protect against ultraviolet radiation before exposure. These findings, however, await confirmation by other researchers.

Allopathic treatment

Aspirin can ease pain and inflammation. Tender skin should be protected against the sun until it has healed.

In addition, people suffering from sunburn may apply:

• calamine lotion
• sunburn cream or spray
• cool tap-water compresses
• colloidal oatmeal (Aveeno) baths
• dusting powder to reduce chafing

People who are severely sunburned should see a doctor, who may prescribe corticosteroid cream to speed healing and prescription pain medication. Topical corticosteroids that have been shown to be safe as well as effective in treating sunburn include methylprednisolone aceponate and hydrocortisone 17-butyrate.

Expected results

Moderately burned skin should heal within a week. While the skin will heal after a sunburn, the risk of skin

cancer increases with exposure and subsequent burns. Even one bad burn in childhood carries an increased risk of skin cancer.

Prevention

Sun protection education

Concern about the rising rate of melanoma in Europe, Australia, and the United States has led public health experts to recommend adding instruction about the importance of sun protection to elementary and junior high school programs. A 1999 cross-sectional study of boys and girls in all 50 states found that 83% of the students had at least one sunburn during the previous summer, with 36% reporting three or more episodes of sunburn. Only 34% used sunscreen. As of 1998, only 3.4% of schools in the United States had sun protection policies to protect students from excessive sun exposure during recess or athletic practice. A standardized program of sun protection education developed by the EPA in 2000 has been reported to be effective in changing students' attitudes toward tanning and the importance of using sunscreen.

Specific preventive measures

To prevent sunburn, everyone over the age of six months should use a water-resistant sunscreen with a sun protective factor (SPF) of at least 15. Apply at least an ounce of sunscreen 15–30 minutes before going outside. It should be reapplied every two hours (more often after swimming). Babies should be kept completely out of the sun for the first six months of life, because their skin is thinner than the skin of older children. Sunscreens have not been approved for infants. Some people are allergic to para-aminobenzoic acid (PABA), a major ingredient in sunscreen products. They should check all labels or consult a doctor prior to application.

In addition, people should follow these guidelines:

• Limit sun exposure to 15 minutes the first day, even if the weather is hazy; then slowly increase exposure daily.
• Reapply sunscreen every two hours (more often if swimming or perspiring heavily).
• Reapply waterproof sunscreen after swimming more than 80 minutes, after toweling off, or after perspiring heavily.
• Avoid exposure to the sun between 10 a.m. and 3 p.m.
• Use waterproof sunscreen on legs and feet, since sun rays can burn even through water.
• Wear an opaque shirt in water, because reflected rays are intensified.

Patients using a sunscreen rated lower than SPF 15 should note that simply applying more of the same SPF won't prolong allowed time in the sun. Instead, patients should use a higher SPF in order to safely lengthen their exposure time. A billed cap protects 70% of the face; a wide-brimmed hat is better. People at very high risk for skin cancer can wear clothing that blocks almost all UV rays, but most people can simply wear white cotton summer-weight clothing with a tight weave. As of 2001, the U.S. Food and Drug Administration requires all sunscreen makers to label their products as providing minimum, moderate, or high levels of sun protection.

Resources

BOOKS

Blumenthal, Mark. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicine. Boston: Integrative Medicine Communications, 1999.

Orkin, Milton, Howard Maibach, and Mark Dahl. Dermatology. Norwalk, CT: Appleton & Lange, 1992.

PERIODICALS

Buller, D. B., A. C. Geller, M. Cantor, et al. "Sun Protection Policies and Environmental Features in US Elementary Schools." Archives of Dermatology 138 (June 2002): 771-774.

Duteil, L., C. Queille-Roussel, B. Lorenz et al. "A Randomized, Controlled Study of the Safety and Efficacy of Topical Corticosteroid Treatments of Sunburn in Healthy Volunteers." Clinical and Experimental Dermatology 27 (June 2002): 314-318.

Geller, A. C., M. Cantor, D. R. Miller, et al. "The Environmental Protection Agency's National SunWise School Program: Sun Protection Education in US Schools (1999-2000)." Journal of the American Academy of Dermatology 46 (May 2002): 683-689.

Geller, A. C., G. Colditz, S. Oliveria, et al. "Use of Sunscreen, Sunburning Rates, and Tanning Bed Use Among More Than 10 000 US Children and Adolescents." Pediatrics 109 (June 2002): 1009-1014.

Ozkur, M. K., M. S. Bozkurt, B. Balabanli, et al. "The Effects of EGb 761 on Lipid Peroxide Levels and Superoxide Dismutase Activity in Sunburn." Photodermatology, Photoimmunology and Photomedicine 18 (June 2002): 117-120.

Tyler, Varro. "Aloe: Nature's Skin Soother." Prevention 50 (April 1, 1998): 94-96.

ORGANIZATIONS

American Academy of Dermatology. 930 East Woodfield Rd., PO Box 4014, Schaumburg, IL 60168. (847) 330-0230. <www.aad.org>.

Environmental Protection Agency. Ten regional offices with region-specific addresses and phone numbers. <www.epa.gov>.

Ken R. Wells

Rebecca J. Frey, PhD

Sunburn

Definition

Sunburn is an inflammation of the skin caused by overexposure to ultraviolet radiation from the sun.

Description

Sunburn is caused by exposure to the ultraviolet (UV) rays of the sun. There are two types of ultraviolet rays, UVA and UVB. UVB radiation causes most sunburn (about 85%). However, most UVB rays are absorbed by sunscreens , but only about half the UVA rays are absorbed.

Although sunburn itself is not a serious health problem in the short term, skin cancer from sun overexposure is in the early 2000s a growing problem in the United States. Both UVA and UVB radiation play a role in the development of a form of skin cancer called malignant melanoma. According to the American Cancer Society, melanoma accounts for only 4 percent of all skin cancer, but 79 percent of skin cancer deaths, or about 7,900 deaths annually in the United States. In addition, more than 1 million Americans develop nonmelanoma skin cancer each year, although deaths from this form of cancer are much more rare (about 1,000 per year).

Skin contains a protective pigment called melanin. The darker the skin tone, the more melanin is present. Fair-skinned people are most susceptible to sunburn, because their skin produces only small amounts of the melanin. However, even the darkest-skinned people can get sunburn and skin cancer.

Infants are most susceptible to sunburn and should be kept out of the sun at all times. Children are more susceptible than adults, and because of their outdoor activities get three times more sun exposure on average than adults. It is estimated that one-half to three-quarters of an individual's total number of lifetime sunburns occur in childhood and adolescence .

Long-term effects of repeated sun overexposure and burning can cause premature aging and wrinkling of the skin. Overexposure can increase the risk of skin cancer, especially a serious burn in childhood. Individuals at highest risk for developing melanoma are those who have intermittent severe (blistering) sunburns in youth or adolescence.

Occasionally an allergic response to a drug will cause a skin reaction resembling sunburn in the absence of sun exposure.

Demographics

Infants and children are more likely to get sunburned than adults. Individuals who live in areas where the climate is mostly sunny year round (Arizona, southern California) are at higher risk both for sunburn and skin cancer. Those living at high altitudes are also at higher risk. The chance of being sunburned increases about 4 percent or every 1,000 feet (300 meters) rise in altitude. Fair-skinned, pale, freckled individuals are more likely to get sunburned than individuals with darker skin. Sunburn is extremely common. One poll found that in the summer of 1997, 13 percent of children had developed a sunburn in the preceding week.

Causes and symptoms

The ultraviolet rays in sunlight destroy cells in the outer layer of the skin, damaging tiny blood vessels underneath. When the skin is burned, the blood vessels dilate and leak fluid. Cells stop making certain proteins because their DNA is damaged by the ultraviolet rays. Repeated DNA damage can lead to cancer.

KEY TERMS

Antibiotics —Drugs that are designed to kill or inhibit the growth of the bacteria that cause infections.

Prophylaxis —Protection against or prevention of a disease. Antibiotic prophylaxis is the use of antibiotics to prevent a possible infection.

Stevens-Johnson syndrome —A severe inflammatory skin eruption that occurs as a result of an allergic reaction or respiratory infection.

Toxoplasmosis —A parasitic infection caused by the intracellular protozoan Toxoplasmosis gondii. Humans are most commonly infected by swallowing the oocyte form of the parasite in soil (or kitty litter) contaminated by feces from an infected cat; or by swallowing the cyst form of the parasite in raw or undercooked meat.

When UV rays burn the skin, immune system defenses that identify the burned skin as foreign are triggered. At the same time, the UV rays transform a substance on the skin that interferes with this immune response. While this keeps the immune system from attacking a person's own skin, it also means that any malignant (cancerous) cells in the skin will be able to grow freely.

Sunburn causes skin to turn red and blister. Symptoms appear from one to 24 hours after sun exposure and peak several days later, after which dead skin cells peel off. In severe cases, the burn may occur with sunstroke (vomiting , fever , and collapse). Severe cases of sunburn may require hospitalization .

When to call the doctor

The doctor should be called any time there are symptoms of heatstroke, dehydration , blurred vision (possible sun damage to the eyes), chills, fever, vomiting, or blistering associated with sun exposure.

Diagnosis

Sunburn is easily diagnosed by visual inspection of the skin. No laboratory tests are needed.

Treatment

In most cases, treatment involves making the sunburned person more comfortable. The individual should get out of the sun and protect tender skin against more sun exposure for at least one week. Pain can be treated with acetaminophen (Tylenol) or nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen. Individuals with moderate sunburn over a large area should drink extra water to avoid dehydration. In addition, discomfort may be reduced by using the following:

• calamine lotion
• sunburn cream or spray
• cool tap water compress
• colloidal oatmeal baths
• moisturizer creams to reduce skin peeling

People who are severely sunburned should see a doctor who may prescribe corticosteroid cream to speed healing. Extreme sunburns that blister may require treatment in a hospital burn unit and intravenous fluids to prevent dehydration. Individuals who develop sunburn as the result of a drug reaction should see a doctor promptly.

Alternative treatment

Over-the-counter preparations containing aloe (Aloe barbadensis ) are an effective treatment for sunburn, easing pain and inflammation while also relieving dryness of the skin. A variety of topical herbal remedies applied as lotions, poultices, or compresses may also help relieve the effects of sunburn. Calendula (Calendula officinalis ) is one of the most frequently recommended to reduce inflammation.

Prognosis

Short-term prognosis is excellent. Moderately burned skin should heal within a week. While the skin will heal after sunburn, the risk of skin cancer increases with exposure and subsequent burns . Even one bad burn in childhood carries an increased risk of skin cancer.

Prevention

Infants under the age of six months should be kept strictly out of the sun. Sunscreens have not been approved for use by infants. Everyone age six months and older should use a water-resistant sunscreen having a sun protective factor (SPF) of at least 15, with an SPF of 30 or more strongly recommended for children. Sunscreen should be applied 15–30 minutes before going outside, as it takes that long to bond effectively with the skin and become effective. Sunscreen should be reapplied every two hours (more often after swimming).

In addition, people should take the following steps:

• Limit sun exposure to 15 minutes the first day, even if the weather is hazy, slowly increasing exposure daily.
• Reapply waterproof sunscreen after swimming for more than 80 minutes, after toweling off, or after perspiring heavily, or every two hours if not swimming.
• Avoid the sun between 10 A.M. and 3 P.M. when the sun is strongest and most direct.
• Wear a hat or cap to protect the face.
• Use sunscreen when participating in snow activities such as skiing where sunlight is reflected off the snow.
• Wear an opaque shirt on water, because reflected rays are intensified.

Parental concerns

Parents, concern about their child's sun exposure is usually influenced by their own experience with tanning and sunburn. Until the early 2000s, a tan was considered healthy rather than an increased cancer risk. Many adolescents still desire a tanned look but should be discouraged from as much sun exposure as possible. Those who insist on tanning should be encouraged to tan gradually and avoid burns.

KEY TERMS

Malignant melanoma —The most serious of the three types of skin cancer, malignant melanoma arises from the melanocytes, the skin cells that produce the pigment melanin.

Sunscreen —A product that blocks the damaging rays of the sun. Good sunscreens contain either para-aminobenzoic acid (PABA) or benzophenone, or both. Sunscreen protection factors range from two to 45.

Sunstroke —Heatstroke caused by direct exposure to the sun in which body temperature increases to dangerously high levels.

See also Heat disorders.

Resources

BOOKS

Auerbach, Paul S. "Acute Effects of Ultraviolet Radiation on Skin: Sunburn and Tanning." Wilderness Medicine,4th ed. St Louis, MO: Mosby, 2001.

Hill, David, et al. Prevention of Skin Cancer. London: Kluwer Law International, 2003.

McNally, Robert Aquinas. Skin Health Information for Teens: Health Tips about Dermatological Concerns and Skin Cancer Risks. Detroit, MI: Omnigraphics, 2003.

ORGANIZATIONS

American Cancer Society. 1599 Clifton Road, Atlanta, GA 30329. Web site: <www.cancer.org>.

WEB SITES

Guenther, Lyn, and Benjamin Barankin. "Sunburn." eMedicine Medical Library, October 27, 2004. Available online at <www.emedicine.com/ped/topic2561.htm> (accessed December 1, 2004).

Takayesu, James K., and Randy P. Prescilla. "Sunburn." eMedicine Medical Library, April 28, 2003. Available online at <www.emedicine.com/wild/topic71.htm> (accessed December 1, 2004).

Tish Davidson, A.M. Carol A. Turkington

Sunburn

Definition

Inflammation of the skin caused by overexposure to the sun.

Description

Sunburn is caused by exposure to the ultraviolet (UV) rays of the sun. There are two types of ultraviolet rays, UVA and UVB. UVA rays penetrate the skin more deeply and can cause melanoma in susceptible people. UVB rays, which don't penetrate as deeply, cause sunburn and wrinkling. Most UVB rays are absorbed by sunscreens, but only about half the UVA rays are absorbed.

Skin cancer from sun overexposure is a serious health problem in the United States, affecting almost a million Americans each year. One out of 87 will develop malignant melanoma, the most serious type of skin cancer, and 7,300 of them will die each year.

Fair-skinned people are most susceptible to sunburn, because their skin produces only small amounts of the protective pigment called melanin. People trying to get a tan too quickly in strong sunlight are also more vulnerable to sunburn. While they have a lower risk, even the darkest-skinned people can get skin cancer.

Repeated sun overexposure and burning can prematurely age the skin, causing yellowish, wrinkled skin. Overexposure can increase the risk of skin cancer, especially a serious burn in childhood.

Causes and symptoms

The ultraviolet rays in sunlight destroy cells in the outer layer of the skin, damaging tiny blood vessels underneath. When the skin is burned, the blood vessels dilate and leak fluid. Cells stop making protein. Their DNA is damaged by the ultraviolet rays. Repeated DNA damage can lead to cancer.

When the sun burns the skin, it triggers immune defenses which identify the burned skin as foreign. At the same time, the sun transforms a substance on the skin which interferes with this immune response. While this substance keeps the immune system from attacking a person's own skin, it also means that any malignant cells in the skin will be able to grow freely.

Sunburn causes skin to turn red and blister. Several days later, the dead skin cells peel off. In severe cases, the burn may occur with sunstroke (vomiting, fever and collapse).

Diagnosis

Visual inspection and a history of exposure to the sun.

Treatment

Aspirin can ease pain and inflammation. Tender skin should be protected against the sun until it has healed. In addition, apply:

• calamine lotion
• sunburn cream or spray
• cool tap water compress
• colloidal oatmeal (Aveeno) baths
• dusting powder to reduce chafing

People who are severely sunburned should see a doctor, who may prescribe corticosteroid cream to speed healing.

Alternative treatment

Over-the-counter preparations containing aloe (Aloe barbadensis ) are an effective treatment for sunburn, easing pain and inflammation while also relieving dryness of the skin. A variety of topical herbal remedies applied as lotions, poltices, or compresses may also help relieve the effects of sunburn. Calendula (Calendula officinalis ) is one of the most frequently recommended to reduce inflammation.

Prognosis

Moderately burned skin should heal within a week. While the skin will heal after a sunburn, the risk of skin cancer increases with exposure and subsequent burns. Even one bad burn in childhood carries an increased risk of skin cancer.

Prevention

Everyone from age six months on should use a water-resistant sunscreen with a sun protective factor (SPF) of at least 15. Apply at least an ounce 15-30 minutes before going outside. It should be reapplied every two hours (more often after swimming). Babies should be kept completely out of the sun for the first six months of life, because their skin is thinner than older children. Sunscreens have not been approved for infants.

KEY TERMS

Malignant melanoma— The most deadly of the three types of skin cancer.

Sunscreen— Products which block the damaging rays of the sun. Good sunscreens contain either para-aminobenzoic acid (PABA) or benzophenone, or both. Sunscreen protection factors range from 2-45.

In addition, people should:

• limit sun exposure to 15 minutes the first day, even if the weather is hazy, slowly increasing exposure daily
• reapply sunscreen every two hours (more often if sweating or swimming)
• reapply waterproof sunscreen after swimming more than 80 minutes, after toweling off, or after perspiring heavily
• avoid the sun between 10 A.M. and 3 P.M.

• use waterproof sunscreen on legs and feet, since the sun can burn even through water
• wear an opaque shirt in water, because reflected rays are intensified

If using a sunscreen under SPF 15, simply applying more of the same SPF won't prolong allowed time in the sun. Instead, patients should use a higher SPF in order to lengthen exposure safely. A billed cap protects 70% of the face; a wide-brimmed hat is better. People at very high risk for skin cancer can wear clothing that blocks almost all UV rays, but most people can simply wear white cotton summer-weight clothing with a tight weave.

Resources

PERIODICALS

Tyler, Varro. "Aloe: Nature's Skin Soother." Prevention Magazine April 1, 1998: 94-96.

sun·burn / ˈsənˌbərn/ • n. reddening, inflammation, and, in severe cases, blistering and peeling of the skin caused by overexposure to the ultraviolet rays of the sun.• v. (past and past part. -burned or -burnt) (be sunburned) (of a person or bodily part) suffer from sunburn: most of us managed to get sunburnt. ∎  [usu. as adj.] (sunburned or sunburnt) ruddy from exposure to the sun: a handsome sunburned face. ∎  [intr.] suffer from sunburn: a complexion that sunburned easily.

sunburn (sun-bern) n. damage to the skin by excessive exposure to the sun's rays, principally UVB (see ultraviolet radiation). Sunburn may vary from reddening of the skin to the development of large painful fluid-filled blisters (see burn).