This is likely to be the case for atopic eczema, an inflammatory skin disease that usually starts in early childhood. It appears that this dermatitis is associated with genetic predispositions that affect the skin barrier. Made more permeable, the skin allows various environmental allergens to pass into the body, causing the immune system to over-react. But there is another type of eczema – contact eczema or contact dermatitis – which occurs without any genetic predispositions when the skin comes into direct contact with a particular allergenic substance.