Atopic Dermatitis
Contents
Defining Atopic Dermatitis
Atopic
dermatitis is a chronic (long-lasting) disease that affects the
skin. It is not contagious; it cannot be passed from one person to
another. The word "dermatitis" means inflammation of the skin. "Atopic"
refers to a group of diseases where there is often an inherited
tendency to develop other allergic conditions, such as asthma and
hay fever. In atopic dermatitis, the skin becomes extremely itchy.
Scratching leads to redness, swelling, cracking, "weeping" clear
fluid, and finally, crusting and scaling. In most cases, there are
periods of time when the disease is worse (called exacerbations or
flares) followed by periods when the skin improves or clears up
entirely (called remissions). As some children with atopic
dermatitis grow older, their skin disease improves or disappears
altogether, although their skin often remains dry and easily
irritated. In others, atopic dermatitis continues to be a
significant problem in adulthood.
Although
atopic dermatitis may occur at any age, it most often begins in
infancy and childhood.
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Atopic
dermatitis is often referred to as "eczema," which is a general term
for the several types of inflammation of the skin. Atopic dermatitis
is the most common of the many types of eczema. Several have very
similar symptoms. Types of eczema are described in the box on page
5.
Incidence
and Prevalence of Atopic Dermatitis
Atopic
dermatitis is very common. It affects males and females and accounts
for 10 to 20 percent of all visits to dermatologists (doctors who
specialize in the care and treatment of skin diseases). Although
atopic dermatitis may occur at any age, it most often begins in
infancy and childhood. Scientists estimate that 65 percent of
patients develop symptoms in the first year of life, and 90 percent
develop symptoms before the age of 5. Onset after age 30 is less
common and is often due to exposure of the skin to harsh or wet
conditions. Atopic dermatitis is a common cause of workplace
disability. People who live in cities and in dry climates appear
more likely to develop this condition.
Although it is
difficult to identify exactly how many people are affected by
atopic dermatitis, an estimated 20 percent of infants and young
children experience symptoms of the disease. Roughly 60 percent of
these infants continue to have one or more symptoms of atopic
dermatitis in adulthood. This means that more than 15 million people
in the United States have symptoms of the disease.
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Types of Eczema
(Dermatitis)
-
Allergic
contact eczema (dermatitis): a red, itchy, weepy reaction
where the skin has come into contact with a substance that the
immune system recognizes as foreign, such as poison ivy or
certain preservatives in creams and lotions
-
Atopic
dermatitis: a chronic skin disease characterized by itchy,
inflamed skin
-
Contact
eczema: a localized reaction that includes redness, itching,
and burning where the skin has come into contact with an
allergen (an allergy-causing substance) or with an irritant
such as an acid, a cleaning agent, or other chemical
-
Dyshidrotic eczema: irritation of the skin on the palms of
hands and soles of the feet characterized by clear, deep
blisters that itch and burn
-
Neurodermatitis: scaly patches of the skin on the head, lower
legs, wrists, or forearms caused by a localized itch (such as
an insect bite) that become intensely irritated when scratched
-
Nummular
eczema: coin-shaped patches of irritated skin-most common on
the arms, back, buttocks, and lower legs-that may be crusted,
scaling, and extremely itchy
-
Seborrheic eczema: yellowish, oily, scaly patches of skin on
the scalp, face, and occasionally other parts of the body
-
Stasis
dermatitis: a skin irritation on the lower legs, generally
related to circulatory problems
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Cost of Atopic Dermatitis
In a recent
analysis of the health insurance records of 5 million Americans
under age 65, medical researchers found that approximately 2.5
percent had atopic dermatitis. Annual insurance payments for medical
care of atopic dermatitis ranged from $580 to $1,250 per patient.
More than one-quarter of each patient's total health care costs were
for atopic dermatitis and related conditions. The researchers
project that U.S. health insurance companies spend more than $1
billion per year on atopic dermatitis.
Causes of Atopic Dermatitis
The cause of
atopic dermatitis is not known, but the disease seems to result from
a combination of genetic (hereditary) and environmental factors.
Children are
more likely to develop this disorder if one or both parents have had
it or have had allergic conditions like asthma or hay fever. While
some people outgrow skin symptoms, approximately three-fourths of
children with atopic dermatitis go on to develop hay fever or
asthma. Environmental factors can bring on symptoms of atopic
dermatitis at any time in individuals who have inherited the atopic
disease trait.
Atopic
dermatitis is also associated with malfunction of the body’s
immune system.
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Atopic
dermatitis is also associated with malfunction of the body's immune
system: the system that recognizes and helps fight bacteria and
viruses that invade the body. Scientists have found that people with
atopic dermatitis have a low level of a cytokine (a protein) that is
essential to the healthy function of the body's immune system and a
high level of other cytokines that lead to allergic reactions. The
immune system can become misguided and create inflammation in the
skin even in the absence of a major infection. This can be viewed as
a form of autoimmunity, where a body reacts against its own tissues.
In the past,
doctors thought that atopic dermatitis was caused by an emotional
disorder. We now know that emotional factors, such as stress, can
make the condition worse, but they do not cause the disease.
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Skin Features of
Atopic Dermatitis
-
Atopic
pleat (Dennie-Morgan fold): an extra fold of skin that
develops under the eye
-
Cheilitis: inflammation of the skin on and around the lips
-
Hyperlinear palms: increased number of skin creases on the
palms
-
Hyperpigmented eyelids: eyelids that have become darker in
color from inflammation or hay fever
-
Ichthyosis: dry, rectangular scales on the skin
-
Keratosis pilaris: small, rough bumps, generally on the face,
upper arms, and thighs
-
Lichenification: thick, leathery skin resulting from constant
scratching and rubbing
-
Papules:
small raised bumps that may open when scratched and become
crusty and infected
-
Urticaria: hives (red, raised bumps) that may occur after
exposure to an allergen, at the beginning of flares, or after
exercise or a hot bath
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Symptoms of Atopic
Dermatitis
Symptoms
(signs) vary from person to person. The most common symptoms are
dry, itchy skin and rashes on the face, inside the elbows and behind
the knees, and on the hands and feet. Itching is the most important
symptom of atopic dermatitis. Scratching and rubbing in response to
itching irritates the skin, increases inflammation, and actually
increases itchiness. Itching is a particular problem during sleep
when conscious control of scratching is lost.
The most
common symptoms are dry, itchy skin and rashes on the face,
inside the elbows and behind the knees, and on the hands and
feet.
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The appearance
of the skin that is affected by atopic dermatitis depends on the
amount of scratching and the presence of secondary skin infections.
The skin may be red and scaly, be thick and leathery, contain small
raised bumps, or leak fluid and become crusty and infected. The box
on page 8 lists common skin features of the disease. These features
can also be found in people who do not have atopic dermatitis or who
have other types of skin disorders.
Atopic
dermatitis may also affect the skin around the eyes, the eyelids,
and the eyebrows and lashes. Scratching and rubbing the eye area can
cause the skin to redden and swell. Some people with atopic
dermatitis develop an extra fold of skin under their eyes. Patchy
loss of eyebrows and eyelashes may also result from scratching or
rubbing.
Researchers
have noted differences in the skin of people with atopic dermatitis
that may contribute to the symptoms of the disease. The outer layer
of skin, called the epidermis, is divided into two parts: an inner
part containing moist, living cells, and an outer part, known as the
horny layer or stratum corneum, containing dry, flattened, dead
cells. Under normal conditions the stratum corneum acts as a
barrier, keeping the rest of the skin from drying out and protecting
other layers of skin from damage caused by irritants and infections.
When this barrier is damaged, irritants act more intensely on the
skin.
Atopic
dermatitis may also affect the skin around the eyes, the
eyelids, and the eyebrows and lashes.
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The skin of a
person with atopic dermatitis loses moisture from the epidermal
layer, allowing the skin to become very dry and reducing its
protective abilities. Thus, when combined with the abnormal skin
immune system, the person's skin is more likely to become infected
by bacteria (for example, Staphylo-coccus and Streptococcus) or
viruses, such as those that cause warts and cold sores.
Stages of Atopic Dermatitis
When atopic
dermatitis occurs during infancy and childhood, it affects each
child differently in terms of both onset and severity of symptoms.
In infants, atopic dermatitis typically begins around 6 to 12 weeks
of age. It may first appear around the cheeks and chin as a patchy
facial rash, which can progress to red, scaling, oozing skin. The
skin may become infected. Once the infant becomes more mobile and
begins crawling, exposed areas, such as the inner and outer parts of
the arms and legs, may also be affected. An infant with atopic
dermatitis may be restless and irritable because of the itching and
discomfort of the disease. The skin may improve by 18 months of age,
although the infant has a greater than normal risk of developing dry
skin or hand eczema later in life.
In childhood,
the rash tends to occur behind the knees and inside the elbows; on
the sides of the neck; around the mouth; and on the wrists, ankles,
and hands. Often, the rash begins with papules that become hard and
scaly when scratched. The skin around the lips may be inflamed, and
constant licking of the area may lead to small, painful cracks in
the skin around the mouth.
In some
children, the disease goes into remission for a long time, only to
come back at the onset of puberty when hormones, stress, and the use
of irritating skin care products or cosmetics may cause the disease
to flare.
It is also
possible for the disease to show up first in adulthood.
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Although a
number of people who developed atopic dermatitis as children also
experience symptoms as adults, it is also possible for the disease
to show up first in adulthood. The pattern in adults is similar to
that seen in children; that is, the disease may be widespread or
limited to only a few parts of the body. For example, only the hands
or feet may be affected and become dry, itchy, red, and cracked.
Sleep patterns and work performance may be affected, and long-term
use of medications to treat the atopic dermatitis may cause
complications. Adults with atopic dermatitis also have a
predisposition toward irritant contact dermatitis, where the skin
becomes red and inflamed from contact with detergents, wool,
friction from clothing, or other potential irritants. It is more
likely to occur in occupations involving frequent hand washing or
exposure to chemicals. Some people develop a rash around their
nipples. These localized symptoms are difficult to treat. Because
adults may also develop cataracts, the doctor may recommend regular
eye exams.
Diagnosing Atopic Dermatitis
Each person
experiences a unique combination of symptoms, which may vary in
severity over time. The doctor will base a diagnosis on the symptoms
the patient experiences and may need to see the patient several
times to make an accurate diagnosis and to rule out other diseases
and conditions that might cause skin irritation. In some cases, the
family doctor or pediatrician may refer the patient to a
dermatologist (doctor specializing in skin disorders) or allergist
(allergy specialist) for further evaluation.
A medical
history may help the doctor better understand the nature of a
patient's symptoms, when they occur, and their possible causes. The
doctor may ask about family history of allergic disease; whether the
patient also has diseases such as hay fever or asthma; and about
exposure to irritants, sleep disturbances, any foods that seem to be
related to skin flares, previous treatments for skin-related
symptoms, and use of steroids or other medications. A preliminary
diagnosis of atopic dermatitis can be made if the patient has three
or more features from each of two categories: major features and
minor features. Some of these features are listed in the box on page
14.
Currently,
there is no single test to diagnose atopic dermatitis.
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Currently,
there is no single test to diagnose atopic dermatitis. However,
there are some tests that can give the doctor an indication of
allergic sensitivity.
Pricking the
skin with a needle that contains a small amount of a suspected
allergen may be helpful in identifying factors that trigger flares
of atopic dermatitis. Negative results on skin tests may help rule
out the possibility that certain substances cause skin inflammation.
Positive skin prick test results are difficult to interpret in
people with atopic dermatitis because the skin is very sensitive to
many substances, and there can be many positive test sites that are
not meaningful to a person's disease at the time. Positive results
simply indicate that the individual has IgE (allergic) antibodies to
the substance tested. IgE (immunoglobulin E) controls the immune
system's allergic response and is often high in atopic dermatitis.
Recently, it
was shown that if the quantity of IgE antibodies to a food in the
blood is above a certain level, it is diagnostic of a food allergy.
If the level of IgE to a specific food does not exceed the level
needed for diagnosis but a food allergy is suspected, a person might
be asked to record everything eaten and note any reactions.
Physician-supervised food challenges (that is, the introduction of a
food) following a period of food elimination may be necessary to
determine if symptomatic food allergy is present. Identifying the
food allergen may be difficult when a person is also being exposed
to other possible allergens at the same time or symptoms may be
triggered by other factors, such as infection, heat, and humidity.
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Major
and Minor Features of Atopic Dermatitis
Major Features
-
Intense
itching
-
Characteristic rash in locations typical of the disease
-
Chronic
or repeatedly occurring symptoms
-
Personal
or family history of atopic disorders (eczema, hay fever,
asthma)
Some Minor
Features
-
Early
age of onset
-
Dry skin
that may also have patchy scales or rough bumps
-
High
levels of immunoglobulin E (IgE), an antibody, in the blood
-
Numerous
skin creases on the palms
-
Hand or
foot involvement
-
Inflammation around the lips
-
Nipple
eczema
-
Susceptibility to skin infection
-
Positive
allergy skin tests
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Factors That
Make Atopic Dermatitis Worse
Many factors
or conditions can make symptoms of atopic dermatitis worse, further
triggering the already overactive immune system, aggravating the
itch-scratch cycle, and increasing damage to the skin. These factors
can be broken down into two main categories: irritants and
allergens. Emotional factors and some infections and illnesses can
also influence atopic dermatitis.
Irritants are
substances that directly affect the skin and, when present in high
enough concentrations with long enough contact, cause the skin to
become red and itchy or to burn. Specific irritants affect people
with atopic dermatitis to different degrees. Over time, many
patients and their family members learn to identify the irritants
causing the most trouble. For example, frequent wetting and drying
of the skin may affect the skin barrier function. Also, wool or
synthetic fibers and rough or poorly fitting clothing can rub the
skin, trigger inflammation, and cause the itch-scratch cycle to
begin. Soaps and detergents may have a drying effect and worsen
itching, and some perfumes and cosmetics may irritate the skin.
Exposure to certain substances, such as solvents, dust, or sand, may
also make the condition worse. Cigarette smoke may irritate the
eyelids. Because the effects of irritants vary from one person to
another, each person can best determine what substances or
circumstances cause the disease to flare.
Allergens are
substances from foods, plants, animals, or the air that inflame the
skin because the immune system overreacts to the substance.
Inflammation occurs even when the person is exposed to small amounts
of the substance for a limited time. Although it is known that
allergens in the air, such as dust mites, pollens, molds, and dander
from animal hair or skin, may worsen the symptoms of atopic
dermatitis in some people, scientists aren't certain whether
inhaling these allergens or their actual penetration of the skin
causes the problems. When people with atopic dermatitis come into
contact with an irritant or allergen they are sensitive to,
inflammation-producing cells become active. These cells release
chemicals that cause itching and redness. As the person responds by
scratching and rubbing the skin, further damage occurs.
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Common Irritants
-
Wool or
synthetic fibers
-
Soaps
and detergents
-
Some
perfumes and cosmetics
-
Substances such as chlorine, mineral oil, or solvents
-
Dust or
sand
-
Cigarette smoke
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A number of
studies have shown that foods may trigger or worsen atopic
dermatitis in some people, particularly infants and children. In
general, the worse the atopic dermatitis and the younger the child,
the more likely food allergy is present. An allergic reaction to
food can cause skin inflammation (generally an itchy red rash),
gastrointestinal symptoms (abdominal pain, vomiting, diarrhea),
and/or upper respiratory tract symptoms (congestion, sneezing, and
wheezing). The most common allergenic (allergy-causing) foods are
eggs, milk, peanuts, wheat, soy, and fish. A recent analysis of a
large number of studies on allergies and breastfeeding indicated
that breastfeeding an infant for at least 4 months may protect the
child from developing allergies. However, some studies suggest that
mothers with a family history of atopic diseases should avoid eating
common allergenic foods during late pregnancy and breastfeeding.
In addition to
irritants and allergens, emotional factors, skin infections, and
temperature and climate play a role in atopic dermatitis. Although
the disease itself is not caused by emotional factors, it can be
made worse by stress, anger, and frustration. Interpersonal problems
or major life changes, such as divorce, job changes, or the death of
a loved one, can also make the disease worse.
Bathing
without proper moisturizing afterward is a common factor that
triggers a flare of atopic dermatitis. The low humidity of winter or
the dry year-round climate of some geographic areas can make the
disease worse, as can overheated indoor areas and long or hot baths
and showers. Alternately sweating and chilling can trigger a flare
in some people. Bacterial infections can also trigger or increase
the severity of atopic dermatitis. If a patient experiences a sudden
flare of illness, the doctor may check for infection.
Treatment of Atopic
Dermatitis
Treatment is
more effective when a partnership develops that includes the
patient, family members, and doctor. The doctor will suggest a
treatment plan based on the patient's age, symptoms, and general
health. The patient or family member providing care plays a large
role in the success of the treatment plan by carefully following the
doctor's instructions and paying attention to what is or is not
helpful. Most patients will notice improvement with proper skin care
and lifestyle changes.
Treatment is
more effective when a partnership develops that includes the
patient, family members, and doctor.
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The doctor has
two main goals in treating atopic dermatitis: healing the skin and
preventing flares. These may be assisted by developing skin care
routines and avoiding substances that lead to skin irritation and
trigger the immune system and the itch-scratch cycle. It is
important for the patient and family members to note any changes in
the skin's condition in response to treatment, and to be persistent
in identifying the treatment that seems to work best.
Medications: New medications known as immuno-modulators
have been developed that help control inflammation and reduce immune
system reactions when applied to the skin. Examples of these
medications are tacrolimus ointment (Protopic*) and pimecrolimus
cream (Elidel). They can be used in patients older than 2 years of
age and have few side effects (burning or itching the first few days
of application). They not only reduce flares, but also maintain skin
texture and reduce the need for long-term use of corticosteroids.
*Brand names
included in this booklet are provided as examples only, and their
inclusion does not mean that these products are endorsed by the
National Institutes of Health or any other Government agency. Also,
if a particular brand name is not mentioned, this does not mean or
imply that the product is unsatisfactory.
Corticosteroid
creams and ointments have been used for many years to treat atopic
dermatitis and other autoimmune diseases affecting the skin.
Sometimes over-the-counter preparations are used, but in many cases
the doctor will prescribe a stronger corticosteroid cream or
ointment. When prescribing a medication, the doctor will take into
account the patient's age, location of the skin to be treated,
severity of the symptoms, and type of preparation (cream or
ointment) that will be most effective. Sometimes the base used in
certain brands of corticosteroid creams and ointments irritates the
skin of a particular patient. Side effects of repeated or long-term
use of topical corticosteroids can include thinning of the skin,
infections, growth suppression (in children), and stretch marks on
the skin.
Corticosteroid
creams and ointments have been used for many years to treat
atopic dermatitis and other autoimmune diseases affecting the
skin.
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When topical
corticosteroids are not effective, the doctor may prescribe a
systemic corticosteroid, which is taken by mouth or injected instead
of being applied directly to the skin. An example of a commonly
prescribed corticosteroid is prednisone. Typically, these
medications are used only in resistant cases and only given for
short periods of time. The side effects of systemic corticosteroids
can include skin damage, thinned or weakened bones, high blood
pressure, high blood sugar, infections, and cataracts. It can be
dangerous to suddenly stop taking corticosteroids, so it is very
important that the doctor and patient work together in changing the
corticosteroid dose.
Antibiotics to
treat skin infections may be applied directly to the skin in an
ointment, but are usually more effective when taken by mouth. If
viral or fungal infections are present, the doctor may also
prescribe specific medications to treat those infections.
Certain
antihistamines that cause drowsiness can reduce nighttime scratching
and allow more restful sleep when taken at bedtime. This effect can
be particularly helpful for patients whose nighttime scratching
makes the disease worse.
In adults,
drugs that suppress the immune system, such as cyclosporine,
methotrexate, or azathioprine, may be prescribed to treat severe
cases of atopic dermatitis that have failed to respond to other
forms of therapy. These drugs block the production of some immune
cells and curb the action of others. The side effects of drugs like
cyclosporine can include high blood pressure, nausea, vomiting,
kidney problems, headaches, tingling or numbness, and a possible
increased risk of cancer and infections. There is also a risk of
relapse after the drug is stopped. Because of their toxic side
effects, systemic corticosteroids and immunosuppressive drugs are
used only in severe cases and then for as short a period of time as
possible. Patients requiring systemic corticosteroids should be
referred to dermatologists or allergists specializing in the care of
atopic dermatitis to help identify trigger factors and alternative
therapies.
In rare cases,
when home-based treatments have been unsuccessful, a patient may
need a few days in the hospital for intense treatment.
Phototherapy: Use of ultraviolet A or B light waves, alone
or combined, can be an effective treatment for mild to moderate
dermatitis in older children (over 12 years old) and adults. A
combination of ultraviolet light therapy and a drug called psoralen
can also be used in cases that are resistant to ultraviolet light
alone. Possible long-term side effects of this treatment include
premature skin aging and skin cancer. If the doctor thinks that
phototherapy may be useful to treat the symptoms of atopic
dermatitis, he or she will use the minimum exposure necessary and
monitor the skin carefully.
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Treating Atopic Dermatitis in Infants and Children
-
Give
lukewarm baths.
-
Apply
lubricant immediately following the bath.
-
Keep
child's fingernails filed short.
-
Select
soft cotton fabrics when choosing clothing.
-
Consider
using sedating antihistamines to promote sleep and reduce
scratching at night.
-
Keep the
child cool; avoid situations where overheating occurs.
-
Learn to
recognize skin infections and seek treatment promptly.
-
Attempt
to distract the child with activities to keep him or her from
scratching.
-
Identify
and remove irritants and allergens.
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Skin
Care: Healing the skin and keeping it healthy are important
to prevent further damage and enhance quality of life. Developing
and sticking with a daily skin care routine is critical to
preventing flares.
A lukewarm
bath helps to cleanse and moisturize the skin without drying it
excessively. Because soaps can be drying to the skin, the doctor may
recommend use of a mild bar soap or nonsoap cleanser. Bath oils are
not usually helpful.
After bathing,
a person should air-dry the skin, or pat it dry gently (avoiding
rubbing or brisk drying), and then apply a lubricant to seal in the
water that has been absorbed into the skin during bathing. In
addition to restoring the skin's moisture, lubrication increases the
rate of healing and establishes a barrier against further drying and
irritation. Lotions that have a high water or alcohol content
evaporate more quickly, and alcohol may cause stinging. Therefore,
they generally are not the best choice. Creams and ointments work
better at healing the skin.
Another key to
protecting and restoring the skin is taking steps to avoid repeated
skin infections. Signs of skin infection include tiny pustules
(pus-filled bumps), oozing cracks or sores, or crusty yellow
blisters. If symptoms of a skin infection develop, the doctor should
be consulted and treatment should begin as soon as possible.
Protection from Allergen Exposure: The doctor may suggest
reducing exposure to a suspected allergen. For example, the presence
of the house dust mite can be limited by encasing mattresses and
pillows in special dust-proof covers, frequently washing bedding in
hot water, and removing carpeting. However, there is no way to
completely rid the environment of airborne allergens.
Changing the
diet may not always relieve symptoms of atopic dermatitis. A change
may be helpful, however, when the medical history, laboratory
studies, and specific symptoms strongly suggest a food allergy. It
is up to the patient and his or her family and physician to decide
whether the dietary restrictions are appropriate. Unless properly
monitored by a physician or dietitian, diets with many restrictions
can contribute to serious nutritional problems, especially in
children.
Atopic Dermatitis
and Quality of Life
Despite the
symptoms caused by atopic dermatitis, it is possible for people with
the disorder to maintain a good quality of life. The keys to quality
of life lie in being well-informed; awareness of symptoms and their
possible cause; and developing a partnership involving the patient
or caregiving family member, medical doctor, and other health
professionals. Good communication is essential. (See "Tips for
Working With Your Doctor" on page 26.)
When a child
has atopic dermatitis, the entire family may be affected. It is
helpful if families have additional support to help them cope with
the stress and frustration associated with the disease. A child may
be fussy and difficult and unable to keep from scratching and
rubbing the skin. Distracting the child and providing activities
that keep the hands busy are helpful but require much effort on the
part of the parents or caregivers. Another issue families face is
the social and emotional stress associated with changes in
appearance caused by atopic dermatitis. The child may face
difficulty in school or with social relationships and may need
additional support and encouragement from family members.
Adults with
atopic dermatitis can enhance their quality of life by caring
regularly for their skin and being mindful of the effects of the
disease and how to treat them. Adults should develop a skin care
regimen as part of their daily routine, which can be adapted as
circumstances and skin conditions change. Stress management and
relaxation techniques may help decrease the likelihood of flares.
Developing a network of support that includes family, friends,
health professionals, and support groups or organizations can be
beneficial. Chronic anxiety and depression may be relieved by
short-term psychological therapy.
Recognizing
the situations when scratching is most likely to occur may also
help. For example, many patients find that they scratch more when
they are idle, and they do better when engaged in activities that
keep the hands occupied. Counseling also may be helpful to identify
or change career goals if a job involves contact with irritants or
involves frequent hand washing, such as kitchen work or auto
mechanics.
Atopic
Dermatitis and Vaccination Against Smallpox
Although
scientists are working to develop safer vaccines, persons diagnosed
with atopic dermatitis (or eczema) should not receive the current
smallpox vaccine. According to the Centers for Disease Control and
Prevention (CDC), a U.S. Government organization, persons who have
ever been diagnosed with atopic dermatitis, even if the condition is
mild or not presently active, are more likely to develop a serious
complication if they are exposed to the virus from the smallpox
vaccine.
People with
atopic dermatitis should exercise caution when coming into close
physical contact with a person who has been recently vaccinated, and
make certain the vaccinated person has covered the vaccination site
or taken other precautions until the scab falls off (about 3 weeks).
Those who have had physical contact with a vaccinated person's
unhealed vaccination site or to their bedding or other items that
might have touched that site should notify their doctor,
particularly if they develop a new or unusual rash.
During a
smallpox outbreak, these vaccination recommendations may change.
Persons with atopic dermatitis who have been exposed to smallpox
should consult their doctor about vaccination.
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Tips for Working
With Your Doctor
-
Provide
complete, accurate medical information.
-
Make a
list of your questions and concerns in advance.
-
Be
honest and share your point of view with the doctor.
-
Ask for
clarification or further explanation if you need it.
-
Talk to
other members of the health care team, such as nurses,
therapists, or pharmacists.
-
Don't
hesitate to discuss sensitive subjects with your doctor.
-
Discuss
changes to any medical treatment or medications with your
doctor.
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Additional
information about atopic dermatitis and smallpox vaccination is
available from CDC. (See "Additional Resources" section of this
booklet.)
Current Research
Researchers
supported by the National Institute of Arthritis and Musculoskeletal
and Skin Diseases and other institutes of the National Institutes of
Health are gaining a better understanding of what causes atopic
dermatitis and how it can be managed, treated, and, ultimately,
prevented. Some promising avenues of research are described below.
Genetics: Although atopic dermatitis runs in families, the
role of genetics (inheritance) remains unclear. It does appear that
more than one gene is involved in the disease.
Research has
helped shed light on the way atopic dermatitis is inherited. Studies
show that children are at increased risk for developing the disorder
if there is a family history of other atopic disease, such as hay
fever or asthma. The risk is significantly higher if both parents
have an atopic disease. In addition, studies of identical twins, who
have the same genes, show that in an estimated 80 to 90 percent of
cases, atopic disease appears in both twins. Fraternal (nonidentical)
twins, who have only some genes in common, are no more likely than
two other people in the general population to both have an atopic
disease. These findings suggest that genes play an important role in
determining who gets the disease.
Biochemical Abnormalities: Scientists suspect that changes
in the skin's protective barrier make people with atopic dermatitis
more sensitive to irritants. Such people have lower levels of fatty
acids (substances that provide moisture and elasticity) in their
skin, which causes dryness and reduces the skin's ability to control
inflammation.
Other research
points to a possible defect in a type of white blood cell called a
monocyte. In people with atopic dermatitis, monocytes appear to play
a role in the decreased production of an immune system hormone
called interferon gamma (IFN-γ), which helps regulate allergic
reactions. This defect may cause exaggerated immune and inflammatory
responses in the blood and tissues of people with atopic dermatitis.
Faulty
Regulation of Immunoglobulin E (IgE): As already described
in the section on diagnosis, IgE is a type of antibody that controls
the immune system's allergic response. An antibody is a special
protein produced by the immune system that recognizes and helps
fight and destroy viruses, bacteria, and other foreign substances
that invade the body. Normally, IgE is present in very small
amounts, but levels are high in 80 to 90 percent of people with
atopic dermatitis.
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Controlling Atopic
Dermatitis
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Prevent
scratching or rubbing whenever possible.
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Protect
skin from excessive moisture, irritants, and rough clothing.
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Maintain
a cool, stable temperature and consistent humidity levels.
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Limit
exposure to dust, cigarette smoke, pollens, and animal dander.
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Recognize and limit emotional stress.
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In allergic
diseases, IgE antibodies are produced in response to different
allergens. When an allergen comes into contact with IgE on
specialized immune cells, the cells release various chemicals,
including histamine. These chemicals cause the symptoms of an
allergic reaction, such as wheezing, sneezing, runny eyes, and
itching. The release of histamine and other chemicals alone cannot
explain the typical long-term symptoms of the disease. Research is
underway to identify factors that may explain why too much IgE is
produced and how it plays a role in the disease.
Immune
System Imbalance: Researchers also think that an imbalance
in the immune system may contribute to the development of atopic
dermatitis. It appears that the part of the immune system
responsible for stimulating IgE is overactive, and the part that
handles skin viral and fungal infections is underactive. Indeed, the
skin of people with atopic dermatitis shows increased susceptibility
to skin infections. This imbalance appears to result in the skin's
inability to prevent inflammation, even in areas of skin that appear
normal. In one project, scientists are studying the role of the
infectious bacterium Staphylococcus aureus (S. aureus) in
atopic dermatitis.
Researchers
also think that an imbalance in the immune system may contribute
to the development of atopic dermatitis.
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Researchers
believe that one type of immune cell in the skin, called a
Langerhans cell, may be involved in atopic dermatitis. Langerhans
cells pick up viruses, bacteria, allergens, and other foreign
substances that invade the body and deliver them to other cells in
the immune defense system. Langerhans cells appear to be
hyper-active in the skin of people with atopic diseases. Certain
Langerhans cells are particularly potent at activating white blood
cells called T cells in atopic skin, which produce proteins that
promote allergic response. This function results in an exaggerated
response of the skin to tiny amounts of allergens.
Scientists
have also developed mouse models to study step-by-step changes in
the immune system in atopic dermatitis, which may eventually lead to
a treatment that effectively targets the immune system.
Drug
Research: Some researchers are focusing on new treatments
for atopic dermatitis, including biologic agents, fatty acid
supplements, and new forms of phototherapy. For example, they are
studying how ultraviolet light affects the skin's immune system in
healthy and diseased skin. They are also investigating biologic
agents, including several aimed at modifying the response of the
immune system. A biologic agent is a new type of drug based on
molecules that occur naturally in the body. One promising treatment
is the use of thymopentin to reestablish balance in the immune
system.
Researchers
also continue to look for drugs that suppress the immune system. In
this regard, they are studying the effectiveness of cyclosporine A.
Clinical trials are underway with another drug called FK506, which
is applied to the skin rather than taken orally. Also,
anti-inflammatory drugs have been developed that affect multiple
cells and cell functions, and may prove to be an effective
alternative to corticosteroids in the treatment of atopic
dermatitis.
Several
experimental treatments are being evaluated that attempt to replace
substances that are deficient in people with atopic dermatitis.
Evening primrose oil is a substance rich in gamma-linolenic acid,
one of the fatty acids that is decreased in the skin of people with
atopic dermatitis. Studies to date using evening primrose oil have
yielded contradictory results. In addition, dietary fatty acid
supplements have not proven highly effective. There is also a great
deal of interest in the use of Chinese herbs and herbal teas to
treat the disease. Studies to date show some benefit, but not
without concerns about toxicity and the risks involved in
suppressing the immune system without close medical supervision.
Several
experimental treatments are being evaluated that attempt to
replace substances that are deficient in people with atopic
dermatitis.
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Hope for the Future
Although the
symptoms of atopic dermatitis can be difficult and uncomfortable,
the disease can be successfully managed. People with atopic
dermatitis can lead healthy, productive lives. As scientists learn
more about atopic dermatitis and what causes it, they continue to
move closer to effective treatments, and perhaps, ultimately, a
cure.
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