The Effects of Common Over-the-Counter Moisturizers on Skin Barrier Function: A Randomized, Observer-Blind, Within-Patient, Controlled Study

Secretome of human umbilical cord mesenchymal stem cell maintains skin homeostasis by regulating multiple skin physiological function

Skin is the largest organ in the body and the first defense to resist various diseases and external stimuli that easily cause infection and inflammation. Aseptic inflammation, barrier damage, and foreign aid pressure induce the destruction and damage to the skin microenvironment. Subsequently, it destroys the skin's physiological function, leading to the maintenance and circulation of steady-state imbalance and aggravating the process of skin disorders. Our study evaluated the therapeutic potential of the secretome of human umbilical cord mesenchymal stem cells (UC-CM) for dermatological diseases in adult human skin cells, ex vivo skin tissue, and a 3D skin model. Our data suggested several advantages of UC-CM due to (1) their low cytotoxicity and sensitization properties; (2) their anti-inflammatory capacity for treating inflammatory chronic cutaneous diseases; (3) their enhanced capacity of the skin barrier for treating abnormal barrier metabolism; and (4) their positive impact on restoring skin homeostasis due to effective regulation ability of skin physiological function including cell apoptosis, detoxification, and anti-aging. We thus envisage that the possibility of harnessing the therapeutic potential of UC-CM might benefit patients suffering from inflammatory skin disorders such as atopic dermatitis, acne, and psoriasis.

"Normal" TEWL-How Can it be Defined?: A Systematic Review

BACKGROUND

Transepidermal water loss (TEWL), the total non-eccrine sweat water evaporating from a given area of epidermis over time, is a measurement of skin barrier integrity. Skin diseases (e.g. psoriasis and atopic dermatitis) often result in transient increases in TEWL, so knowledge of "normal" TEWL values may be used to predict disease progression in dermatological settings. Variables such as age, race, and anatomic location have been suggested to affect TEWL, but current regulatory agencies have failed to control for additional variables of interest. Thus, this review summarizes variables that may cause TEWL variation.

METHODS

A comprehensive literature search was performed using Embase, PubMed, and Web of Science to find human studies that provided data on variables affecting TEWL.

RESULTS

31 studies, analyzing 22 affecting TEWL, were identified. Variables causing increased TEWL were mask-use (n=1), Dry Eye Disease (n=1), Chronic Venous Disease (n=1), Coronary Artery Disease (n=1), age (infants vs. adults) (n=4), nourishment in infants (n=1), stress within individuals (n=2), Body Mass Index (n=2), bathing versus showering (n=2), and scratching/friction (n=1). Variables with decreases in TEWL were genetic variability with SNPs on chromosome 9q34.3 (n=1) and cancer-cachexia (n=1).

CONCLUSION

We summarized 12 variables that impact TEWL and are not typically controlled for in experimental settings. Therefore, defining normal TEWL may currently be problematic. Thus, regulatory agencies should provide stricter guidelines on proper measurement of TEWL to minimize human introduced TEWL variation, and we should continue to examine factors impacting individual skin integrity.

Study of Skin Barrier Function in Psoriasis: The Impact of Emollients

Psoriasis is a chronic multi-systemic inflammatory disease that affects the epidermal barrier. Emollients can be used as a coadjutant therapy for psoriasis management, but little is known about how the epidermal barrier function in psoriatic patients is modified by moisturizers. The objective of this study is to evaluate the effect of Vaseline jelly and a water-based formula on epidermal barrier function in psoriatic patients. Thirty-one patients with plaque-type psoriasis and thirty-one gender and age-matched healthy controls were enrolled in the study. Temperature, transepidermal water loss (TEWL), stratum corneum hydration (SCH), pH, elasticity and the erythema index were measured using non-invasive tools before and after applying Vaseline jelly and a water-based formula. TEWL was higher in psoriatic plaques than uninvolved psoriatic skin (13.23 vs. 8.54 g·m^-2·h^-1; p < 0.001). SCH was lower in psoriatic plaques than uninvolved psoriatic skin and healthy skin (13.44 vs. 30.55 vs. 30.90 arbitrary units (AU), p < 0.001). In psoriatic plaques, TEWL decreased by 5.59 g·m^-2·h^-1 (p = 0.001) after applying Vaseline Jelly, while it increased by 3.60 g·m^-2·h^-1 (p = 0.006) after applying the water-based formula. SCH increased by 9.44 AU after applying the water-based formula (p = 0.003). The use of emollients may improve epidermal barrier function in psoriatic patients. TEWL is decreased by using Vaseline, and SCH is increased by using the water-based formula.