The new research found that skin with reduced skin barrier function is prone to UVB-induced irritation.
Additionally, the results also suggest that the barrier function of the stratum corneum can potential protect the skin from ultraviolet irradiation.
These research findings were published in the journal Photodermatology, Photoimmunology, and Photomedicine...
“Kao is going to use these findings in its ongoing search for novel sun protection technologies for skin with low barrier function and high sensitivity, as well as technologies to improve the barrier function in all types of skin,” said the company.
Barrier plays important role in UV protection
Originally, Kao conducted research to determine if there was a link between skin shade and cutaneous barrier function.
Researchers measured the trans-epidermal water loss (TEWL) of 285 female Japanese volunteers aged 30 to 49 years and assessed skin sensitivity against UVB.
This was carried out by determining the lowest UVB irradiation dose to induce redness in the skin.
The study reported that the negative correlation between UV sensitivity and the cutaneous barrier function was significant, and was reproduced twice in more than 250 female volunteers.
This confirmed that participants with a reduced stratum corneum barrier function are prone to UVB-induced erythema.
From this, Kao researchers also deduced that an individual that is susceptible to UVB sunburns may also have lower barrier functions.
“The findings suggest that persons with low barrier function or high susceptibility to UVB sunburn should carefully administer skin care to reinforce their cutaneous barrier function and protect their skin against UVB irradiation.”
However, the study found that skin sensitivity of the stratum corneum does not correlate with skin colour, said the company.
“Darker skin is generally thought to be less prone to sunburn. The analysis, however, indicated that skin sensitivity against UV was negatively correlated not with skin color, but with the cutaneous barrier function.”
Kao claimed that it was among the first to investigate the cutaneous barrier function of the stratum corneum and believes a deeper understanding of it will continue to be important in the future of personal care.
“While people with atopic dermatitis and skin sensitive to stimuli are generally aware that their cutaneous barrier function is low, people with healthy skin tend to know less about this function. Recent research has demonstrated that the transdermal invasion of foreign substances is a greater cause of allergic diseases than oral intake. Findings have further shown that barrier care during infancy helps prevent the development of allergies later in life.”