[Microbial ecosystems of the skin in antimicrobial therapy]

Healthy human skin provides wet, dry, and sebaceous habitats for well-adapted microbes living in a community and occupying three-dimensional spaces of the skin. These resident microbes of the skin are reduced either intentionally or unintentionally under systemic or topical antimicrobial therapy, e.g. in acne or tinea versicolor. As a result, quantitative or qualitative alterations of the microbial communities might ensue, including the selection of multiresistent variants in a habitat or a total change of the microbial community followed by the so-called gram-negative folliculitis. Skin disinfectants are antimicrobially effective within 30 to 60 seconds. Their long-term efficacy varies according to the specific substance. Moreover, the antimicrobial efficacy of skin disinfectants may vary to a considerable degree in the individual habitats of the human skin.