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...