Treatment of Surfactant-Damaged Skin in Humans with Creams of Different pH Values

Abstract

Skin surface has an acidic pH, whereas the body’s internal environment maintains a near-neutral pH. The physiological role of the ‘acidic mantle’ and the function of the pH gradient throughout the stratum corneum remain unexplained. The pH gradient has been suggested to activate enzymes responsible for the maintenance of the skin barrier function and to facilitate the desquamation process in the stratum corneum. The aim of the study was to investigate the influence of pH of a moisturizing cream on barrier recovery in surfactant-damaged human skin. Volunteers had their skin damaged with sodium lauryl sulphate and treated those areas with the cream, adjusted to either pH 4.0 or 7.5. The study did not prove the superiority of a cream of pH 4.0 to a cream of pH 7.5 regarding promotion of skin barrier recovery, since no significant differences (p > 0.05) were found in transepidermal water loss, blood flow and skin capacitance between the treated areas.

Impact of a Glycolic Acid-Containing pH 4 Water-in-Oil Emulsion on Skin pH

“…This effect continued until the end of the study (day 28) and a further decrease was observed. This finding is not in contrast to an independent study by Buraczewska and Lodén [20], where they failed to prove the superiority of a cream of pH 4.0 over a cream of pH 7.5 regarding the promotion of skin barrier recovery. However, application in this study was only for a short-term period of 7 days.…”

A Long-Term Study to Evaluate Acidic Skin Care Treatment in Nursing Home Residents: Impact on Epidermal Barrier Function and Microflora in Aged Skin

“…The reduction in skin surface pH to a physiological level strengthens the SC structure and accelerates EPB repair mechanisms in the elderly, as described in mice by Choi et al [12] . Buraczewska and Lodén [60] demonstrated that treatment with an acidic emulsion (pH 4.0) compared to treatment with a pHneutral product (pH 7.5) did not result in positive effects on SC recovery in younger volunteers. In that age group (21-54 years), physiological skin surface pH levels and a sufficient skin buffering system putatively override pH modulation by acidic products.…”

Skin Barrier Responses to Moisturizers: Functional and Biochemical Changes

“…A study investigating the effect of moisturizers of pH 4 and 7.5 showed that the pH of moisturizers seems not to be of major importance for their effects on the skin barrier: no difference in the impact on skin barrier recovery or susceptibility to an irritant was found [ 50 ] . The lack of difference in effect on skin barrier recovery of the moisturizers with acidic or alkaline pH values in our study disagrees with a previous study in mice, where barrier recovery was delayed after exposure to slightly alkaline pH [ 51 ] .…”

“…In the present investigation, after long-term treatment, moisturizers were examined for their effect on the skin barrier with regard to such factors as pH, lipid type, the presence of a humectant, as well as complexity of the product [27][28][29]50 ] . Moisturizers are able to modify the skin barrier function, detected as changes in TEWL, skin capacitance, and susceptibility to an irritant, and also to change the mRNA expression of certain genes involved in the assembly, differentiation, and desquamation of the stratum corneum, as well as lipid metabolism.…”