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.
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.
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
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: 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.
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 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.
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.
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. 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.
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
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.
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 |
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.
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.
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
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.
References:
National Institutes of Health
(NIH)
Nutritional and Herbal Therapy for
Dermatitis
-
Avoid allergenic foods such as dairy products, soy, tomatoes, peanuts,
wheat, shell fish, eggs, corn, and citrus.
-
Consume more fresh vegetables, whole grains, and essential fatty acids
(cold-water fish, nuts, and seeds).
-
Vitamin E (100 to 400 IU per day), beta-carotene (25,000 to
100,000 IU/day) and zinc (10 to 30 mg per day) to bolster your immune
system and help heal your skin.
-
Flaxseed (3,000 mg twice a day), borage (1,500 mg twice a day) or
evening primrose oil (1,500 mg twice a day) to reduce inflammation
and swelling. Children can take cod liver oil (1/2 to 1 tsp. per
day), or any of the above oils, 500 mg, twice a day.
- From
the
Tao of Nutrition, you can try applying honey to the
affected area, or mashed daikon radish, or fresh potato
(changing every 4 hours, for 3 days). Also, there are a variety of teas that
you can drink that may help: a mung bean/pearl barley combination, a
dandelion/cornsilk combination, or a tea made from lily bulbs/Chinese
black dates/mulberries.
-
Healthy skin begins with healthy amounts of Blood and Qi -
Traditions of Tao's Blood Builder nourishes Blood and Qi.
- The
following Chinese herbal patent formulas can help treat eczema and allergic
dermatitis :
Kai Yeung Pill,
Lian Qiao Bai Du Pian, and
Chuan Shan Jia Qu Shi Qing Du Wan.
-
Apply
Pi Kang Shuang
on the affected areas. This is a Chinese herbal
topical cream that helps relieve itchiness and inflammation.
-
Dr. Li's Protective Moisturizer can help relieve skin dryness and
flakiness.
References:
Tao of Nutrition, by Maoshing Ni, Ph.D., C.A., and Cathy McNease,
B.S., M.H. |