Teens: Tanning - Dangers of Too Much Sun

by Food and Drug Administration (FDA)

Some months after a bad sunburn, Susan, 14, went to a dermatologist (skin doctor) for an unrelated problem. During the visit, the doctor recalled that burn and how Susan's skin had blistered and peeled. The doctor remarked that Susan's skin was now clear, her glowing complexion a picture of perfect skin health. But, he warned, the skin and tissue damage from the sunburn might not show up for years to come. Stop sunbathing, the doctor urged her. Avoid the sun.

But Susan continued to sunbathe for several more summers. Today, 12 years later, she wears sunscreen and avoids sunbathing altogether. What made Susan change her mind about the sun?

"There is no such thing as a safe tan," says Darrel Rigel, M.D., clinical associate professor of dermatology at New York University, Manhattan. "Why does the body tan? Because the body is being injured by ultraviolet [UV] radiation that hits it. This causes the body to make melanin, a natural sun screen. So to get tan, you must get injured first."

Melanin is the dark pigment that skin cells make to block out damaging rays in response to injury from UV radiation.

UV radiation comes in two wavelengths — UVA and UVB — and causes skin damage. According to Arthur Sober, M.D., associate professor of dermatology at Harvard University Medical School, the damage is potentially serious whether it is caused by direct sunlight or tanning devices or by light reflected off snow or water or passing through clouds. "On a cloudy day, a person feels cooler, but is still getting a good amount of UV exposure," he says.

Janusz Beer, Ph.D., D.Sc., senior scientist in the radiation biology branch of FDA's Center for Devices and Radiological Health, explains that in natural light, and depending on the time of day, most UV radiation comes from UVA. Both UVA and UVB can cause damage but most of the damage to DNA (genetic material) in skin cells comes from UVB. This could lead to cell and tissue damage and possibly to skin cancer. In addition, he says, scientists know that UVB impairs the body's immune system, which normally defends against disease.

Both UVA and UVB are present year-round, but UVB is more intense in the summer, at higher altitudes, and near the equator, according to the American Academy of Dermatology.

UVA speeds up skin aging by causing changes in the skin's collagen, the protein in the skin's connective tissue. "Just look at pictures of people who work outside, like farmers and fishermen. They all have wrinkly faces," says Beer. "The more exposure, the more wrinkles."

Sunburns and blistering are the most obvious — and painful — results of short-term sun damage. The long-term damage, such as wrinkling, can be disfiguring and in the case of skin cancer, possibly life-threatening.

Barbara Gilchrest, M.D., chairman of the department of dermatology, Boston University School of Medicine, explains that you can think of the skin damage as happening along parallel tracks that intertwine. Freckling and wrinkling are at one end of the tracks, and skin cancer looms at the other end.

The cosmetic changes — wrinkling, coarseness, and irregular pigmentation — occur on one track. The more sinister changes, such as actinic keratosis — scaly, rough, and red, tan, brownish, or grayish spots on the skin that can lead to cancerous tumors — occur on the other. These changes occur as a person is exposed to UV light, even in infancy, she says. The age when you first can see these changes depends on your complexion, how much and how often you're exposed to the sun, and other factors.

John A. Kenney Jr., M.D., professor of dermatology at Howard University College of Medicine, Washington, D.C., notes that black skin seems to have more protection against UV rays than white skin, due to melanin and perhaps other factors. However, warns Kenney, blacks can sunburn to some degree. And UVA does cause some aging changes in black skin as well.

Gilchrest worries that teens are tanning younger and spending more time in the sun than ever before. The unseen damage that occurs at the age of 16 has 60 years to turn into cancer, she says, but shows up as early as age 30 as wrinkling, uneven skin color, and coarsening of the skin.

"Most skin cancer is a result of exposure to sun when people are young. Children and teens are particularly susceptible," says Jeanne Rippere, an FDA microbiologist who evaluates over-the-counter drugs, including sunscreens.

Cancer Rates Climbing

There are three main types of skin cancer: malignant melanoma, basal cell carcinoma, and squamous cell carcinoma. The least common, but the deadliest, of these is malignant melanoma. Regardless of skin color, all people are vulnerable to skin cancer, although among African Americans, for example, the incidence is very low. For this population, squamous cell carcinoma — which can also be fatal — is the most common.

According to the American Cancer Society, in 1995 there will be 800,000 new cases of all skin cancers, up from 700,000 in 1993 and 400,000 in 1980. The society predicts there will be 34,100 new cases of malignant melanoma — 15,400 in women and 18,700 in men, with 7,200 deaths from melanomas: 4,500 for men and 2,700 for women. According to a 1990 study released by Brown University, about 2 percent of malignant melanomas are in people younger than 20.

There are several reasons for the increase in skin cancer, explains Sydney Hurwitz, M.D., clinical professor of pediatrics and dermatology at Yale University School of Medicine. One is the continuing feeling that a tan is a "badge of affluence, sex appeal, health, and self esteem," he says. Another is the increasing loss of the Earth's ozone layer that blocks the sun's damaging rays.

"There are no figures yet on skin cancers among teens," says Hurwitz. "But I have seen five or six children with melanomas. . . . Ten to 20 percent of those people with melanoma go on to die. There is a 6 to 10 percent rate increase per year. In simple language, each day, maybe 80 to 100 people are diagnosed with melanoma."

According to data presented by NYU's Rigel to the American Cancer Society, there are six risk factors associated with malignant melanoma:

• three or more blistering sunburns during adolescence
• blond or red hair
• marked freckling of the upper back
• actinic keratosis
• other family members with melanoma
• three or more years of outdoor summer jobs as a teenager.

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.