Doctors don't know exactly what causes eczema. The most common type of eczema -- atopic dermatitis -- resembles an allergy. But the skin irritation, which is more often seen in children rather than adults, is not an allergic reaction.
The current thinking is that eczema is caused by a combination of factors that include:
abnormal function of the immune system
activities that may cause skin to be more sensitive
defects in the skin barrier that allow mo...
At a meeting of the American Academy of Allergy, Asthma & Immunology in New Orleans, WebMD spoke with Asriani M. Chu, MD, associate professor of pediatrics and medicine in the division of allergy and immunology at the Medical College of Wisconsin in Milwaukee, about eczema.
What are the symptoms of eczema?
The hallmark is a very itchy skin rash. It is a flatter, red rash as opposed to hives, which are more like raised, itchy, mosquito bite kind of bumps.
The location of the rash is also a telltale sign. In kids, it tends to affect the elbows or behind the knees. Adults tend to have the hands affected. It's often worse in the wintertime, when it’s cold and the air is dry inside due to heaters.
What are the most common causes of eczema?
If an allergic cause is identified, it is going to be more related to foods. Those foods could include commonly allergenic foods such as peanuts, tree nuts, eggs, and milk, for example. There have also been some studies that identified dust mite allergy as being a contributing factor. It is more likely to happen if somebody has a family history.
Are there any practical things that you can do to prevent eczema?
The really important thing is the dysregulation between your body’s moisture level and hydration. So you want to keep skin well moisturized and rehydrated.
Some practical things include bathing at least daily in water that is not too hot. If it’s too hot it can take away the essential oils in the skin. You also don’t want to bathe too long because that can also dry the skin out. After you use kind of lukewarm water in your bath, maybe 10 minutes in length, pat dry the skin -- don’t rub it dry -- and then use moisturizers that are fragrance-free so they're not irritating to the skin.
If your health care provider has prescribed any topical prescription ointments, you would want to use those prescription ointments first, then the moisturizers.
One of the other things that we mention is that “eczema is the itch that rashes, not the rash that itches.” So there may be times that the doctor may prescribe an allergy medication or anti-itching medication so that the person doesn’t scratch all the time.