What is Atopic Dermatitis?
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 the
scratching or from infections.
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 the age 30 and often continue throughout life.
AD is a very common disease, present worldwide, though it is more common in urban areas in developed countries. An estimated 10% of all people are at some time affected by AD (may not apply in the tropics.) It affected 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, including:
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- substance 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 some are allergens.
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 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 suffers must avoid irritants, while those with known allergies should likewise avoid allergens. Detecting an allergic substance can be difficult, as discussed below.
What about food allergies?
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 an AD flare-up, it is important to identify the trigger foods.
Diagnosing food allergies is extremely difficult. The surest way is to observe a worsening of eczema when a particular food is eaten. Sometimes this is only a coincidence with flaring and needs to be verified with a food challenge, where the suspected food is eaten in the doctor’s office. Withholding foods should be done only under the supervision of a physician as serious nutritional damage can be caused by the elimination of foods suspected to cause flare-ups. Patients are seldom allergic to more than one or two food.
A skin test, made by scratching the skin with the suspected allergen, is helpful if the test is negative (indicating that the particular food will not affect the patient). If the scratched area becomes inflamed, the test is considered positive. Positive tests provide a clue to a possible allergy but should not be accepted as the last word. Additionally, because the skin of AD sufferers is so sensitive, simply scratching it can cause inflammation.
In certain circumstances patch testing may be performed to help identify eczema triggers
What about other allergies?
Occasionally people with AD notice a worsening of their condition when exposed to airborne allergens, such as pets or dusty rooms. An allergy to dust mites (tiny organisms present in household dust) may worsen AD in some people.
What about emotional stress?
Many older AD children and adults recognize a relationship between stressful occurrences in their lives and their AD flare-ups. Anger, frustration, and embarrassment all may cause flushing and itching. The resultant scratching can cascade into perpetuating dermatitis.
People with AD can learn how to avoid stress-triggered flare-ups. Two key concepts are involved:
- 1Coping with psychologically stressful events
- 2Controlling scratching behavior
What about climate, heat, humidity?
Extreme cold or hot temperatures, or sudden changes in the temperature, are poorly tolerated by persons with AD. 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.
What about exercise?
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.
What can be done when AD flare-up?
The best line of defense against AD is prevention, but flare-ups rarely can be avoided. Once inflammation begins, prompt treatment as directed by a physician is needed. Bathing or wet compresses may ease the itch.
Cortisone (steroid) creams applied directly to the affected area are helpful and a mainstay of therapy. Overuse of highly potent steroids can be damaging. Cortisone pills or shots are sometimes used, but they are not safe for long-term use. Researchers are seeking new and safer drugs to control the itch and inflammation.
Topical Immunomodulators (TIMs)
TIMs is a new family of topical medications that work to inhibit the skin’s inflammatory response (which is what causes the redness and also contributes to itching). At this time there are two FDA approved non-steroid drugs tacrolimus and pimecrolimus. TIMs are not steroids and do not cause thinning of the skin but they can suppress the immune system in the skin so that the use of sun protection for anyone receiving this therapy is recommended.
What can be done about dry skin?
AD sufferers always have very dry, brittle skin. The external layer of the skin, called the stratum corneum, acts as a protective barrier. When the stratum corneum cracks because of dryness, irritants can reach the sensitive layers below and cause a flare-up of AD.
Using moisturizers is the best and safest treatment to prevent dry skin. Moisturizers trap water beneath the skin, making it flexible and less likely to crack.
Research has found that the most effective moisturizers are ointment bases. Cream base products are also helpful. Moisturizers work best when applied to damp skin. Lotions contain water and alcohol which can actually dry the skin and are usually inadequate for the dry skin of atopics.
People with AD can bathe regularly and use mild skin cleansers as long as they follow these simple rules:
- Use warm, not hot, water
- Avoid excessive scrubbing and toweling, pat dry
- Apply a moisturizer to the skin within 3 minutes after bathing
What can be done about infections?
People with AD are prone to skin infections, especially staph and herpes. In general, infections are hard to prevent but should be treated promptly to avoid aggravating the AD. It is important that persons with AD, or their parents, learn to recognize the early signs of skin infections and consult a physician immediately. Signs to watch for include increased redness, pus-filled bumps (pustules), and cold sores or fever blisters.
Sometimes viral illnesses such as colds or flu cause AD flare-ups. Worsening can be avoided by taking extra skin care while the virus runs its course.
Can sufferers of AD live normal lives?
Yes! People with AD do not have to be limited by their disease. It can be controlled by prevention, medication, and careful adherence to a treatment program supervised by a doctor.
Suggestions for treatment and control:
- Establish a skin care routine. Following the physician’s instructions is crucial for keeping AD under control. This takes a lot of time and effort. Some suffers may resent the effort or even deny that their skin needs special care.Establish a schedule and a regular daily routine. Include skin care along with all other activities of daily living such as brushing and flossing teeth or washing dinner wishes. It is important to maintain a flexible attitude, so that when the dermatitis flares and extra skin care is needed, it can be worked into the routine.
- Be aware of scratching. Keep a record in a diary or calendar of times and situations when scratching is worst, and then try to limit your exposure to such situations. Many people with AD scratch the most during idle times. Engaging in a structured activity with other people or keeping busy with activities that involve the use of your hands may help prevent scratching.
- Control your environment. Avoid irritants and allergens. Avoid low humidity. Wear cotton clothing. Guard against infection. Moisturize. Keep fingernails clean and short.