Skin acidification with a water‐in‐oil emulsion (pH 4) restores disrupted epidermal barrier and improves structure of lipid lamellae in the elderly

Abstract

The pH of the skin surface increases with age and thus reduces epidermal barrier function. Aged skin needs appropriate skin care to counterbalance age‐related pH increase and improve barrier function. This confirmatory randomized study investigated the efficacy of water‐in‐oil (w/o) emulsions with either pH 4 or pH 5.8 in 20 elderly subjects after 4 weeks of treatment. After the treatment, the skin was challenged with a sodium dodecyl sulphate (SDS) solution in order to analyze barrier protection properties of both formulations. The pH 4 w/o emulsion resulted in a significantly lower skin pH compared with the pH 5.8 w/o emulsion and an improved skin hydration after 4‐week treatment. Further, the pH 4 emulsion led to more pronounced improvements in length of intercellular lipid lamellae, lamellar organization as well as lipid levels than the pH 5.8 emulsion. Following SDS‐induced barrier damage to the skin, the pH of all test areas increased, but the area treated with the pH 4 emulsion showed the lowest increase compared with baseline. In addition, even after the SDS challenge the skin area treated with the pH 4 emulsion still maintained a significantly increased length of intercellular lipid lamellae compared with the beginning of the study. This study provides evidence that topical application of a w/o emulsion with pH 4 reacidifies the skin in elderly and has beneficial effects on skin moisturization, regeneration of lipid lamellae and lipid content. Application of a pH 4 emulsion can improve the epidermal barrier as well as the stratum corneum organization in aged skin.

Skin pH–dependent Staphylococcus aureus abundance as predictor for increasing atopic dermatitis severity

“…Compared to water baths, dilute bleach baths do not consistently reduce AD severity and S aureus load in vivo and are not antimicrobial in vitro 45,46 . In the “Guidelines of care for the management of AD” from 2015, rather acidic skin care is advised, more recent publications confirm the benefit of acidification of the skin for improved barrier function in murine models 47–52 . Even a preventive potential was suggested 49,51 .…”

Aging-associated alterations in epidermal function and their clinical significance

“…For example, acidification of aged mouse skin with topical lactobionic acid normalized permeability barrier homeostasis and the structure of corneodesmosomes in the stratum corneum [36]. Likewise, topical applications of an emollient at pH 4.0 for 29 days markedly improve stratum corneum hydration and lamellar bilayer structure, along with increased resistance to challenges from topical sodium dodecyl sulphate, in aged humans [113]. Similarly, compared to a pH 5.8 emollient, a topical pH 4.0 emollient accelerates permeability barrier recovery following acute disruption, and significantly improves stratum corneum integrity after 28-day treatments on aged humans [114].…”

‘Targeted dry skin treatment using a multifunctional moisturizer’

“…The levels of this specific ceramide species have not been determined in this study. However, no increases in the levels of CER EOS generally were observed despite others reporting such improvements and where the increase in the levels of CER EOS is in balance with other ceramides[10,11]. One could assume that if increased levels of CER EOS occur then it is likely its linoleate subspecies might as well.…”

“…Other studies including those using niacinamide-containing formulations are known to increase the total levels of all ceramide species [9]. As the Lipbarvis methodology only evaluates three classes of ceramides, it is important to compare the results of Stettler et al with other treatments where increases in the levels of all the three main ceramides species are observed [10,11]. Another study only shows increased CER EOS levels [12].…”