HuidpH

HuidpH, or skin pH, is the acidity or basicity of the surface of the skin, expressed on the pH scale. It reflects the chemical environment of the stratum corneum and the acid mantle, a protective film that contributes to barrier integrity and microbial defense.

In healthy adults the skin surface is typically slightly acidic, commonly around pH 4.5 to 5.5. This acidic milieu supports enzymatic processes involved in lipid synthesis and desquamation, helps maintain the skin barrier, and limits overgrowth of many microbes. pH values vary by body site, age, climate, and health status. Newborns and very young infants often have a higher, less acidic skin pH that gradually becomes more acidic with age.

pH is measured with calibrated pH meters, skin probes, or colorimetric indicator strips. Readings can be influenced by moisture, temperature, recent washing, and residues from products applied to the skin.

Several factors influence huidpH. Cleansing products with an alkaline pH, hard water, and occlusive conditions can raise skin pH and disrupt the acid mantle. Conversely, pH-balanced cleansers and moisturizers formulated for skin pH roughly 4.5 to 5.5 help maintain barrier function. Environmental factors such as humidity and individual skincare habits also play a role.

Clinical relevance lies in the association between altered huidpH and barrier impairment, dryness, irritation, and changes in the skin microbiota. Some inflammatory skin conditions show pH abnormalities, and restoring a more normal pH can be a consideration in management. For most people, using mild, pH-balanced cleansers and avoiding harsh alkaline products supports a stable skin pH.