What causes atopic eczema?

Skin rash: Eczema "the itch that rashes" is actually caused by a defect in the skin. An allergy or irritant makes the skin itchy & then scratching the skin causes the rash. Removal of allergens & irritants plus moisturizers are the mainstay of treatment. Mild topical steroids are often used to treat the more severe areas. An allergist may be of help in finding out the "aggravating" agents.

Moisture loss: The basic problem in eczema is loss of the normal moisture from the skin causing dry skin. Dry skin itches. Scratching the dry skin (or rubbing it on bedding) causes rash. Therefore eczema has been described as "the itch that rashes." people with eczema are sometimes missing some barrier proteins that prevent moisture loss. 1/3 of eczema may have food allergy triggers, but 2/3 will not.

It's complicated: At it's root, atopic dermatitis is caused by partially inherited defects in the barrier function of the skin and a propensity of the skin to overreact to substances in the environment including naturally occurring bacteria. Treatments focus on improving the skin barrier with strong moisturizers, controlling inflammation, controlling itch and avoiding exacerbating factors.