ABSTRACT

First descriptions of the surface acidity of human epidermis date back to the late 19th century (1). Initially, these reports describe pH as a physiologic variable (2), and later systematic observation of this parameter both in physiology and in disease revealed its connection to biochemical processes in epidermis (3-6). Similarly, a large section of literature is dedicated to pH variations in bodily areas (7), various population groups (8), and the influence of cosmetics and detergents on pH (9). Further, a number of animals display a similar surface acidity, justifying their frequent use as study objects in this field (10,11).