The exact cause of atopic dermatitis (eczema) is unknown, but it's likely due to a combination of dry, irritable skin with a malfunction in the body's immune system. Stress and other emotional disorders can worsen atopic dermatitis, but they don't cause it.

Most experts believe atopic dermatitis has a genetic basis. It has been thought to be connected to asthma and hay fever, but that theory is being questioned. Not all people with atopic dermatitis have asthma or hay fever, and not all people with asthma or hay fever develop atopic dermatitis, but these diseases do seem to be present together in families of those affected.

Aug. 23, 2011