Ph value of the human skin

The healthy skin surface reacts slightly acidic, whereby the pH value depends primarily on the localization, less on age, sex or race. The normal skin pH is the superficial pH value in the area of the forearm of a healthy, adult white man; it is in the range of 5.4 to 5.9. Determined mainly with the flat electrode according to Ingold. Axilla, sole of the foot, interdigital spaces, genitoanal area (physiological gaps in the acid mantle) have a higher pH value (between 6 and 7).

Combination electrodes can be used to measure the pH value where the measuring electrode and reference electrode are integrated in a single electrode. The potential is discharged via electrodes of silver chloride or mercury chloride wire. The Skin pH Meter PH 905 (Courage and Khazaka electronic GmbH, Cologne), for example, is easy to handle. Alternatively, measurements can be made with indicator paper.