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ATOPIC DERMATITIS Atopic
Dermatitis is a
condition that causes itchy, inflamed skin. It typically affects the
insides of the elbows, backs of the knees, and the face, but can cover
most of the body. Atopic dermatitis falls into a category of diseases
called atopic, a term originally used to describe the allergic
conditions asthma and hay fever. People who live in urban areas and in
climates with low humidity seem to be at an increased risk for
developing atopic dermatitis. Symptoms
vary from person to person. The most common symptoms are dry, itchy
skin; cracks behind the ears; and rashes on the cheeks, arms, and legs.
The itchy feeling is an important factor in atopic dermatitis, because
scratching and rubbing in response to itching worsen the skin
inflammation characteristic of this disease. People with atopic
dermatitis seem to be more sensitive to itching and feel the need to
scratch longer in response. They develop what is referred to as “the
itch-scratch cycle”: The extreme itchiness of the skin causes the
person to scratch, which in turn worsens the itch, and so on. Itching is
particularly a problem during sleep, when conscious control of
scratching decreases and the absence of other outside stimuli makes the
itchiness more noticeable. The
way the skin is affected by atopic dermatitis can be changed by patterns
of scratching and resulting skin infections. Some people with the
disease develop red, scaling skin where the immune system in the skin is
becoming very activated. Others develop thick
and leathery skin as a result of constant scratching and rubbing. This
condition is called lichenification. Still others develop papules, or
small raised bumps, on their skin. This can be confused with rosacea.
When the papules are scratched, they may open and become crusty and
infected. These conditions can also be found in people without atopic
dermatitis or with 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 change in appearance. Some people with atopic dermatitis
develop an extra fold of skin under their eyes, called an atopic pleat
or Dennie-Morgan fold. Other people may have hyper-pigmented eyelids,
meaning that the skin on their eyelids darkens from inflammation or hay
fever (allergic shiners). Patchy eyebrows and eyelashes may also result
from scratching or rubbing. Other
symptoms of atopic dermatitis include a reddened face with paleness
around the mouth, darkened circles under the eyes, and additional lines
on the palms of the hands. The
appearance
of the rash may be very
different from one person to another. Scratch marks are often seen,
along with scaly dry skin. The skin may become infected and show yellow
crusts or little, pinpoint, pus-containing bumps. The skin also may
become thickened from long-term scratching and rubbing. Inflammation
results from too many reactive inflammatory cells in the skin. Research
is seeking the reason why these cells over-react. Patients with Atopic
dermatitis (or asthma or hay fever) are born with these over-reactive
cells. When something triggers
them, they don’t turn off as they should. We try to control Atopic
dermatitis by preventing the trigger
factors that turn on inflamed skin, or with anti-inflammatory
therapies. In
childhood, the rash tends to occur behind the knees and inside the
elbows; on the sides of the neck; 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. Severe cases of atopic dermatitis may affect growth, and the
child may be shorter than average. The
condition may go into remission. The length of a remission varies, and
it may last months or even years. In some children, the condition gets
better 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 condition to flare. The
pattern in adults is similar to that seen in children; that is, the
condition may be widespread or limited to a more restricted form. In
some adults, 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, especially if
they are in occupations involving frequent hand wetting or hand washing
or exposure to chemicals. Some people develop a rash around their
nipples. These localized symptoms are difficult to treat, and people
often do not tell their doctor because of modesty or embarrassment.
Adults may also develop cataracts that are difficult to detect because
they cause no symptoms. Therefore, the doctor may recommend regular eye
exams.
Common
trigger factors include:
Avoiding
trigger factors:
Irritants
are substances that cause burning, itching, or redness, such as
solvents, industrial chemicals, detergents, fumes, tobacco smoke,
paints, bleach, woolen fabrics, acidic foods, astringents and other
alcohol-containing skin care products, and some soaps and fragrances. If
an irritant is potent, or concentrated enough, it can irritate
anyone’s skin, whether they have Atopic dermatitis or not. Allergens
are more subtle trigger factors. An allergen does not irritate, but may
trigger a flare-up in those who have become allergic to it from prior
exposure. Allergens are usually animal or vegetable proteins from foods,
pollens, or pets. When
people with Atopic dermatitis are exposed to an irritant or allergen to
which they are sensitive, inflammation-producing cells come into the
skin. There, they release chemicals that cause itching and redness.
Further damage occurs when the person scratches and rubs the affected
area. Food
allergies can cause flare-ups. Since an allergic reaction to food
(either by skin contact during food preparation or by eating the food)
can trigger a flare-up, it is important to identify the trigger foods. Many
sufferers recognize a relationship between stressful occurrences in
their lives and their flare-ups. Anger, frustration, and embarrassment
all may cause flushing and itching. The resultant scratching can cascade
into perpetuating dermatitis. Extreme
cold or hot temperatures, or sudden changes in the temperature, are
poorly tolerated by persons with Atopic dermatitis. High humidity causes
increased sweating and may result in prickly-heat-type symptoms. Low
humidity dries the skin, especially during winter months when homes are
heated. Unfortunately, humidifiers do not help much; the best protection
against "winter itch" is regular application of a good
moisturizer. While you can do little about the climate (and moving to a
new climate is often not possible, anyway), you can try to keep your
home environment comfortable. Keeping thermostats set low and wearing
fewer bedclothes, to prevent night sweating, are two ways to combat the
problem. The
only problem with exercise is that the resultant sweating generally
causes itching. Layers of clothing can be removed to avoid overheating.
Strenuous exercise is best avoided when a flare-up occurs. The
best line of defense is prevention, but flare-ups rarely can be avoided.
Once inflammation begins, prompt treatment is needed. Bathing or wet
compresses may ease the itch. The
skin of a person with atopic dermatitis loses too much moisture from the
epidermal layer, allowing the skin to become very dry and reducing its
protective abilities. In addition, the patient’s skin is very
susceptible to recurring infections, such as staphylococcal and
streptococcal bacterial skin infections and warts, herpes simplex, and
molluscum contagiosum (skin disorders caused by a virus). Currently,
there is no test to diagnose atopic dermatitis and no single symptom or
feature used to identify the disease. Each patient experiences a unique
combination of symptoms, and the symptoms and severity of the disease
may vary over time. The doctor will base his or her diagnosis on the
symptoms the patient experiences and may need to see the patient several
times to make an accurate diagnosis. It is important for the doctor 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 or allergist (allergy specialist) for further
evaluation. |