Text B. Long-term Effects of Sunlight

 

Years of exposure to sunlight age the skin, but exposure before age 18 is probably the most dam­aging. Although fair-skinned people are most vulnerable, with enough exposure, anyone's skin will change.

Damage to the deep skin layers causes wrinkling and yellow discoloration. Sunlight also thins the skin and may induce precancerous growths (actinic keratoses, solar keratoses). These growths appear as flaky, scaly areas that don't heal; they may also be darkened or gray and feel hard. People who are in the sun a lot have an increased risk of skin cancers, including squamous cell carcinoma, basal cell carcinoma, and to some degree, malignant melanoma.

Treatment

The key to treatment is avoiding further sun exposure; however, any damage that's already done can't be reversed. Moisturizing creams and make-up help hide wrinkles. Sometimes, chemical peels, alpha-hydroxy acids, and tretinoin are used in attempts to undo long-term damage, especially very thin wrinkles and irregular pigmentation. Even though the benefits of such treatments have been touted, little convincing evidence exists that deep wrinkles can be smoothed out permanently or that skin damage can be reversed.

Precancerous growths may progress to skin cancer. Solar or actinic keratoses usually can be removed by freezing them with liquid nitrogen; however, if a person has too many growths, a liquid or an ointment containing fluorouracil may be applied. Often, during such treatment, the skin looks worse because fluorouracil causes redness, scaling, and burning of the keratoses and the surrounding sun-damaged skin.

Notes:

vulnerable уязвимый; ранимый

squamous cell carcinoma плоскоклеточная карцинома

basal cell carcinoma базалиома, базально-клеточная карцинома

hide прятать(ся); скрывать(ся) (behind; from)

 

Text C. Skin Photosensitivity Reactions

 

Although sunburn and sun damage take time to show up, some people have unusual reactions after only a few minutes of sun exposure. These reactions include redness, peeling, hives, blisters, and thickened, scaling patches. Many factors may contribute to such sensitivity to the sun (photosensitivity).

The most common cause is the use of certain drugs - such as some antibiotics, diuretics, and antifungal agents. Photosensitivity reactions can also result from soaps, perfumes such as scented toilet waters (especially the ones that contain bergamot and smell like mint or citrus), coal tars used to treat dandruff and eczema, and sub­stances found in plants like meadow grass and parsley. Certain diseases, such as systemic lupus erythematosus and porphyria, also may cause photosensitivity reactions.

Some reactions to light (polymorphous light eruptions) seem to be unrelated to diseases or drugs. For some people, even brief exposure to sun causes hives (red, raised patches) or ery­thema multiforme on sun-exposed areas. Skin re­actions to light are most common in people from temperate climates when they're first intensely exposed to the sun in the spring or summer; such reactions are uncommon in people who are ex­posed to the sun year-round.

Prevention and treatment

Extreme sensitivity to sunlight calls for wearing protective clothes, avoiding sunlight as much as possible, and using sunscreens. A careful review of any diseases, drugs taken by mouth, or sub­stances applied to the skin (such as drugs or cos­metics) may help a doctor pinpoint the cause of the photosensitivity. However, pinpointing the cause is difficult and sometimes impossible.

Sometimes long-term treatment with hydroxy-chloroquine may prevent photosensitivity reactions, and often oral corticosteroids can speed recovery from such reactions. For certain types of photosensitivity, treatment can consist of giv­ing psoralens (drugs that sensitize the skin to sun light) and exposing the skin to UVA light; people with systemic lupus erythematosus can't tolerate this treatment.

Notes:

scented ароматический; благовонный, надушенный

meadow grass мятлик луговой

parsley петрушка

 

Pigment Disorders

 

Skin color is determined by a combination of the pigments produced in the skin and the natural colors of the upper layers of the skin. Without pigmentation, the skin would be pale white with varying shades of pink caused by the blood flow­ing through it. The main skin pigment is melanin, a dark brown pigment made by cells (melanocytes) that are interspersed among the other cells in the upper layer of the skin, the epidermis.

Hypopigmentation, an abnormally low amount of pigment, is usually restricted to small areas of skin. It usually results from a previous inflamma­tory condition of the skin or, in rare instances, may represent a hereditary condition.

When the skin is exposed to sunlight, melanin production increases, causing tanning. Increased amounts of melanin (hyperpigmentation) can be a response to hormonal changes, like those that may take place in Addison's disease, in preg­nancy, or with oral contraceptive use. The skin also can darken in diseases such as hemochromatosis or hemosiderosis or in response to many medications that are applied to the skin, swal­lowed, or injected.

Albinism is a rare, inherited disorder in which no melanin is formed.

People with albinism (albinos) have white hair, pale skin, and pink eyes. Often, they also have abnormal vision and involuntary eye movements (nystagmus).

Because melanin protects the skin from the sun, albinos are prone to sunburn and, therefore, to skin cancers. They can minimize these prob­lems by staying out of direct sunlight wearing sunglasses, and applying sunscreen with a sun protection factor (SPF) rating higher than 15 to uncovered areas of the skin.

Vitiligo is a condition in which a loss of melanocytes results in smooth, whitish patches of skin.

In some people, one or two sharply demarcated patches appear; in others, patches of vitiligo appear over a large part of the body. The changes are most striking in darkly pigmented people. As in albinism, the unpigmented skin is extremely prone to sunburn. The areas of skin affected by vitiligo also produce white hair because the melanocytes are lost from the hair follicles.

Vitiligo may occur after unusual physical trauma, especially head injury, and tends to occur with certain other diseases, including Addison's disease, diabetes, pernicious anemia, and thyroid disease. Vitiligo may be devastating psychologically because of the extreme disfigurement that results from the pigmentary change.

Tinea versicolor is a fungal infection of the skin that may appear similar to vitiligo_, though sometimes it results in hyperpigmentation.

Treatment

No cure is known for vitiligo. Small areas can be camouflaged with various dyes that won't soil clothing and may last for several days. Psoralens (light-sensitive drugs) plus ultraviolet A light (PUVA) treatment is sometimes effective, but the treatment takes a long time and must be contin­ued indefinitely. Sunscreen and coverings that protect against sun exposure can prevent sunburn.

Notes:

intersperse разбрасывать, раскидывать, рассыпать (among, between - среди, между), распространять

prone склонный (к чему-либо), подверженный (чему-либо)

disfigurement физический дефект, недостаток

tinea опоясывающий лишай

versicolor цветоизменяющий

camouflage маскировать; скрывать

Skin Cancers

 

Skin cancer is the most common form of cancer, but most types of skin cancers are curable. The more common forms of skin cancer usually develop on sun-exposed areas. People who have had a lot of sun exposure, particularly people with fair complexions, are most likely to develop skin cancer.