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
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: the system that rec