ABSTRACT
Stratum corneum (SC) acidity, or the ‘‘acid mantle,’’ has been recognized since the 1920s (1,2). The pace of discoveries concerning SC acidity has accelerated during the last decade, partly due to the development of new technology for assessing SC pH, and partly due to the development of new animal models. In addition, SC acidity now is acknowledged to be essential not only in establishing the epidermal permeability barrier, but also in producing the epidermal antimicrobial barrier and in controlling SC integrity and cohesion. SC acidification has been studied in two discrete clinical presentations: establishment during perinatal life and re-establishment after epidermal permeability barrier insult. Current research indicates that these two processes parallel each other, and employ many of the same components.
