Dry skin conditions are related to the recovery rate of skin temperature after cold stress rather than to blood flow

Seasonal variations in the skin parameters of Caucasian women from Central Europe

BACKGROUND

The human skin is greatly affected by external factors such as UV radiation (UVR), ambient temperature (T), and air humidity. These factors oscillate during the year giving rise to the seasonal variations in the skin properties. The aim of this study was to evaluate the effect of seasons, environmental T, relative and absolute humidity on the skin parameters of Caucasian women, perform a literature review and discuss the possible factors lying behind the found changes.

MATERIALS AND METHODS

We measured stratum corneum (SC) hydration, transepidermal water loss (TEWL), sebum level, erythema index, and elasticity parameters R2 and R7 on the forehead and the cheek of Caucasian women from the Czech Republic throughout the year. We also performed a non-systematic literature review focused on the seasonal variations in these skin parameters.

RESULTS

We confirmed a well-documented low SC hydration and sebum production in winter. In spring, we found the lowest TEWL (on the forehead) and the highest SC hydration but also the highest erythema index and the lowest elasticity presumably indicating skin photodamage. For most of the skin parameters, the seasonal variations probably arise due to a complex action of different factors as we extensively discussed.

CONCLUSION

The data about the seasonal variations in the skin parameters are still highly inconsistent and further studies are needed for better understanding of the normal skin changes throughout the year.

Facial application of high-concentration carbon dioxide prevents epidermal impairment associated with environmental changes

Purpose

The transdermal application of carbon dioxide (CO₂) gas dissolved in a solution and bathing in carbonated springs have been known to improve circulatory disorders. We aimed to elucidate and profile the effects of CO₂ application on local skin function.

Patients and methods

A liquid formulation that included high-concentration CO₂ or a control formulation was applied to the face of healthy men for 8 weeks. Quantitative analysis was performed during the dry winter months.

Results

At the site where the control formulation was applied, transepidermal water loss (TEWL) increased while the moisturizing function (conductance) of facial skin decreased during the study period. However, at the CO₂-treated site, increases in TEWL and decreases in conductance were significantly suppressed. In addition, the deterioration in scaliness and wrinkles parameters were suppressed by ≥40% at the CO₂-treated site. There were no significant differences in skin surface pH or color properties between the control and test sites.

Conclusion

This study suggests that the continuous application of a high-concentration CO₂ formulation can affect skin physiology and has the potential to suppress reductions in the barrier and moisturizing functions of the stratum corneum accompanied by desquamation, which occurs during the winter.

Ingestion of Coffee Polyphenols Improves a Scaly Skin Surface and the Recovery Rate of Skin Temperature after Cold Stress: A Randomized, Controlled Trial

Coffee polyphenols (CPPs) derived from coffee beans have beneficial effects on blood pressure and vascular endothelial function. In addition, CPPs suppress ultraviolet light induced erythema. However, the effects of CPPs on dry skin and cutaneous vascular function have not been clarified. We investigated the effects of CPPs on dry skin and the recovery rate (RR) of skin temperature after a cold-stress test as a measure of vascular function in subjects with visible scaliness in a double-blind, placebo-controlled, randomized study. The subjects were divided into two groups, the CPP group and the Placebo group. In the CPP group, the subjects ingested a beverage containing 297.8 mg CPPs every day for 4 wk. The degree of skin dryness was assessed quantitatively using a Visioscan to evaluate skin scaliness and smoothness. A subjective evaluation using a visual analog scale (VAS) of skin smoothness was also used. As a result, the scaliness and smoothness of cheek skin was significantly improved after 4 wk in the CPP group compared to the Placebo group. The improvements of the VAS score on 'skin smoothness' and the RR were also observed in the CPP group but the difference was not statistically significant. However, when the CPP group was divided into subgroups of high RR and low RR, the improvement of the RR was significant in the low RR subgroup. In conclusion, our results suggest that CPPs improve skin scaliness and play a role in cutaneous blood flow regulation after cold stress.