Alterations of colonizing features of skin bacteria and influence on therapeutic responses in atopic dermatitis

Colonization of Staphylococcus aureus is one of the important aggravating factors in atopic dermatitis. As far as we live in daily life, however, it is impossible to eradicate all bacteria from the skin and keep it aseptic for long. Neither antimicrobial nor antiseptic treatment is promising for eradication of colonizing S. aureus in the horny layers covered with biofilm. Nevertheless, antimicrobial and antiseptic treatments including popidone iodine have been used for atopic dermatitis, with evidence of the decrease of bacterial counts on the skin and some clinical improvements after the treatments. These results, however, should be interpreted and reevaluated carefully. We believe that control of overgrowth of S. aureus in atopic dermatitis should be achieved by proper skin cares and standard treatments for dermatitis, in consideration of the effect of normal bacterial flora, barrier functions of normal horny layers, and expression of antimicrobial peptides.