Recent studies have identified IL-31 and IL-33 as a critical pruritogenic cytokines in humans and in mice because over expression of IL-31 and IL-33 in the skin enhances pruritus and atopic dermatitis phenotypes in mice [5]; and atopic skin lesions in both humans and in mice express very high levels of these two cytokines [4]. This evidence concerns the gene IL33 and atopic eczema.