What is Atopic Dermatitis (AD)?

Atopic dermatitis (AD) is a disease 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. AD falls into a category of diseases called atopic, a term originally used to describe the allergic conditions asthma and hay fever. AD was included in the atopic category because it often affects people who either suffer from asthma and/or hay fever or have family members who do. Physicians often refer to these three conditions as the “atopic triad.” AD is not contagious. Research indicates that atopic diseases like AD are genetically determined, inherited from one’s parents. A child with one parent who has an atopic condition has a one in four chance of having some form of atopic disease. If both parents are atopic, the child has a greater than one in two chance of being atopic.

AD almost always begins in childhood, usually during infancy. Its symptoms are dry, itchy, scaly skin, cracks behind the ears, and rashes on the cheeks, arms and legs. It alternately improves and worsens. During “flare-ups,” open weeping or crusted sores may develop from scratching or from infections. Often the problem fades during childhood though people with AD have a lifelong tendency to have:

DRY SKIN — easily irritated


SKIN INFECTIONS — staph and herpes

EYE PROBLEMS — eyelid dermatitis, cataracts



Children affected by AD may suffer from asthma and hay fever at the same time, or one or both of these conditions may develop later. These diseases usually appear before age 30 and often continue throughout life.

AD is a very common disease, present worldwide, though it is more common in urban areas and developed countries. An estimated 10 percent of all people are at some time affected by AD (this may not apply in the tropics). It affects men and women of all races equally.

Is eczema the same as AD?

Eczema is a general term for any type of dermatitis or “inflammation of the skin.” Atopic dermatitis (AD) is the most severe and chronic (long-lasting) kind of eczema. Although the term eczema is often used for atopic dermatitis, there are several other skin diseases that are eczemas as well. A partial list of eczemas includes: atopic dermatitis, nummular eczema, dyshidrotic eczema, seborrheic dermatitis, irritant contact dermatitis, allergic contact dermatitis. All types of eczema cause itching and redness and some will blister, weep or peel.

What sets off AD?

AD tends to flare-up when the person is exposed to certain trigger factors—substances or conditions which worsen the dermatitis such as dry skin, irritants, allergens, emotional stress, heat and sweating, and infections.The key to controlling AD is avoiding or reducing such exposure. People with atopic diseases are usually sensitive to certain agitating substances. Some of these substances are irritants and others are allergens. Irritants are substances that cause burning, itching or redness such as solvents, industrial chemicals, detergents, fumes, tobacco smoke, paints, bleach, woolens, 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 AD or not.

Allergens are more subtle trigger factors. An allergen does not irritate, but may trigger an AD 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 AD 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. All AD sufferers must avoid irritants, while those with known allergies should likewise avoid allergens. Detecting an allergic substance can be difficult, as discussed below