Among several microbes colonising the skin, the bacterium Staphylococcus aureus (S. aureus) may play the most important role in the pathogenesis of dermatitis of atopic people (Biedermann 2006). This colonization is observed not only in the involved inflammatory skin but also in the non involved dry skin. The ratio Staphylococcus aureus / Staphylococcus epidermidis is inverse in comparison to healthy skin. Many studies have shown that the extent of S. aureus colonization correlates with AD disease intensity (Cho et al., 2001).