VOICE ONE:
This is SCIENCE IN THE NEWS in VOA Special English. I'm Barbara Klein.
VOICE TWO:
And I'm Bob Doughty. Today, we will tell about some disorders of the skin,
and ways to treat them.
(MUSIC)
VOICE ONE:
Skin. It is the largest organ of the body. Skin is the body's first barrier
to infection. It keeps out many harmful bacteria and other things. It also keeps
all the things we need in our bodies.
The skin helps control body temperature. Glands on the skin release fluid to
cool the body when it gets too hot. When a person gets too cold, blood passages
in the skin become narrow. This helps to trap heat inside the body.
VOICE TWO:
Like other organs of the body, the skin can have problems. Almost any
teenager can tell you the most common disorder: acne. Acne is connected to
hormones and how they affect the oil glands of the skin.
The skin gets its oil, called sebum, from the sebaceous glands. Each gland
connects to a passage of extremely small hairs. The sebum travels through these
passages. The oil reaches the surface of the skin through little holes, called
pores. Sometimes, the sebum, hair and cells of the pores block these openings.
This is how acne starts.
Bacteria can grow in a blocked pore. The bacteria produce chemicals and
enzymes. White blood cells -- infection fighters -- travel to the area. All this
leads to a growth on the skin, a pimple. This becomes red, hot and often
painful.
VOICE ONE:
Some people think eating chocolate or oily foods causes acne. Others blame
dirty skin or nervous tension. Yet researchers tell us none of these cause acne.
So what does? Doctors are not sure. But they have some ideas. For one thing,
they know that hormones called androgens are involved. Androgens cause the
sebaceous glands to grow and make more oil.
Young people will not be happy about this next fact. Androgens increase when
boys and girls enter their teenage years.
VOICE TWO:
There are several treatments for acne. Mild cases are generally treated with
medicines for use directly on the skin. These often contain salicylic acid or
benzoyl peroxide.
People with more serious acne may be given antibiotic drugs to take by mouth.
Or they might use a combination of other treatments.
One drug used to treat the most severe forms of acne is called isotretinoin.
It is sold under different names, including Accutane.
Isotretinoin has been shown to cure acne in ninety percent of people who use
it. The drug is normally taken for about five months. However, it can cause
serious problems in some cases. If used during pregnancy, for example,
isotretinoin can harm the developing fetus. That is why health experts strongly
advise pregnant women and those who may become pregnant against using the drug.
VOICE ONE:
Skin experts say there are simple ways to help prevent acne. One is to touch
your face as little as possible, so as not to add oils or put pressure on the
skin.
Another good idea is to avoid the urge to burst pimples. This can leave
permanent marks on the skin.
Doctors also say to avoid strong cleaning products, and to be gentle as you
wash and dry your skin.
(MUSIC)
VOICE TWO:
A 13-year-old boy shows the scar from the removal of a cancerous growth
on his arm
Some skin problems are far more serious than acne. There are
several kinds of skin cancer, for example.
Skin cancer is often the result of time spent in the sun. Light and heat from
the sun can change chemicals in the skin. The sun produces ultraviolet radiation
that causes the skin to burn and, over time, develop cancer.
The most serious skin cancer is melanoma. It begins in the cells that produce
skin color. Melanomas can develop anywhere. They are usually found on the back
and the shoulders.
Most melanomas are black or brown. They can look like
other kinds of growths. But they are the deadliest form of skin cancer. So it is
important to watch for signs that can help identify melanoma. Treating it early
can make the difference between life and death.
People should see a doctor immediately if they find a growth of a strange
shape, with uneven sides or edges. A growth of different colors or one larger
than six millimeters also should be examined.
VOICE ONE:
The usual treatment for melanoma is an operation to remove the growth. After
the surgery, patients often take drugs to kill any cancer cells that remain.
Doctors may also order radiation treatment. Radiation kills cancer cells and
reduces the size of cancerous growths.
There also are experimental treatments for melanoma. Researchers are working
on ways to genetically change white blood cells. The goal is to help the body
increase its own efforts to destroy the cancer.
Researchers are also testing a possible melanoma vaccine. It would not
prevent the disease like traditional vaccines. Instead, it would help the body
fight the cancer in a way similar to the genetic treatment.
However, the best thing is to reduce the chances that you might ever get
melanoma. Doctors tell people to limit the amount of time they spend in
sunlight. They also suggest wearing hats and other protective clothing. And,
they urge people to use products that help protect the skin from the sun.
VOICE TWO:
Yet there are times when doctors use ultraviolet light to treat some skin
problems -- like psoriasis, for example. Psoriasis creates raised areas of skin
that are dry and cause an itchy feeling. They are found most often on the
elbows, knees and head. But psoriasis can spread to cover larger areas.
It usually begins before twenty or after fifty years of age. Recent studies
have shown that the disorder causes the body's defense system to produce too
many skin cells.
There is no cure, but some treatments can improve the condition. One involves
the use of ultraviolet light in the doctor's office to reduce swelling and slow
skin cell production. This is sometimes used in combination with a drug called
psoralen.
Psoriasis seems to pass down from parent to child. Researchers have
identified genes linked to psoriasis.
VOICE ONE:
Another skin disorder is atopic dermatitis, commonly called eczema. It
creates areas of skin that itch and become rough. Eczema is most common in
babies. At least half of those cases clear up within a few years. But, in
adults, this painful condition generally never goes away completely.
Persons with eczema often also suffer from allergic conditions like asthma
and seasonal hay fever. Like psoriasis, there is no cure for eczema. But there
are treatments with steroid drugs and also some newly developed kinds without
steroids.
Environmental conditions can also influence development of eczema. That is
why doctors often advise patients not to use cleaners that contain soap, which
can make skin dry. Even water can cause dry skin, which can make eczema worse.
So can temperature changes and stress.
(MUSIC)
VOICE TWO:
Some skin disorders do not cause any physical pain. But, they can cause
emotional pain by how they affect the appearance of the skin. Vitiligo for
example, is the destruction of the pigment cells. This disease causes areas of
the skin to lose all color. Even the hairs turn white.
For some people, the white areas of vitiligo appear only in one or two
places. Others find pigment loss on just one side of their bodies. Most people,
however, develop many such areas all over their skin.
Around the world, up to sixty-five million people have vitiligo. It affects
all races and both sexes.
Doctors do not know the cause. However, as with some other skin disorders,
they suspect that the body's immune system is involved.
VOICE ONE:
To treat vitiligo, some patients receive psoralen and ultraviolet light. A
number of steroid drugs can also help, especially when started early in the
disease.
Doctors may also wish to operate to treat severe cases of vitiligo. However,
American health experts say all operations should be considered only after the
patient has received other medical treatment.
One such operation involves the removal of a very small piece of healthy skin
from the patient. The skin is placed in a substance that helps it grow more
pigment cells. These new cells are then placed in the areas where the patient
needs pigment.
Vitiligo can cause extreme changes in a person's appearance. That is why
there are mental health experts and support groups to help people who have this
disease.
(MUSIC)
VOICE TWO:
SCIENCE IN THE NEWS was written by Caty Weaver. Brianna Blake was our
producer. I'm Barbara Klein.
VOICE ONE:
And, I'm Bob Doughty.
Join us again next week for more news about science in Special
English on the Voice of
America.
點擊進入更多VOA慢速
（來源:VOA 英語點津姍姍編輯）
