Effects of blue light on inflammation and skin barrier recovery following acute perturbation. Pilot study results in healthy human subjects

Abstract

We provide the first in vivo evidence that blue light at 453 nm exerts biological effects on acutely perturbed healthy human skin.

Effects of red light on inflammation and skin barrier recovery following acute perturbation. Pilot study results in healthy human subjects

“…A delaying effect of blue light on the recovery of the skin barrier was instead observed with a single irradiation with blue light. 1 Thirdly, red light led to a slight decrease in b* value at 24 hours after tape stripping compared to the control. Blue light, on the contrary, increased the b* value at both 24 hours and 72 hours after tape stripping.…”

“…In an original article recently published in Photodermatology, Photoimmunology, and Photomedicine, 1 we aimed to prove therapeutic effects of photobiomodulation (PBM) based on clinical outcomes by investigating the impact of UV-free blue light at 453 nm on the recovery of the skin barrier and on the cutaneous inflammatory response elicited by acute perturbation of the skin of healthy human volunteers. In this Letter, we describe a study of same design and scope in which we investigated the impact of LED red light at 656 nm.…”

Noninvasive analysis and minimally invasive in vivo experimental challenges of the skin barrier

“…In many studies, biopsies were taken to investigate these responses at the immunohistochemical level, revealing in a synchronized way the presence of a dermal inflammatory infiltrate, epidermal spongiosis, a stark increase in epidermal proliferation, as well as the presence of parakeratosis and hyperkeratosis . Other studies used biophysical analysis techniques only, or a combination of biophysical analysis techniques and skin biopsies . At the functional level, the acute abrogation of the SC is mirrored by a sharp increase in TEWL and dermal blood concentration measured by diffuse reflectance spectroscopy (DRS); at the morphological level, parakeratosis, hyperkeratosis and epidermal thickness increase due to proliferation and spongiosis can be recognized in RCM images .…”

“…Other studies used biophysical analysis techniques only, or a combination of biophysical analysis techniques and skin biopsies . At the functional level, the acute abrogation of the SC is mirrored by a sharp increase in TEWL and dermal blood concentration measured by diffuse reflectance spectroscopy (DRS); at the morphological level, parakeratosis, hyperkeratosis and epidermal thickness increase due to proliferation and spongiosis can be recognized in RCM images . Representative images of the use of biophysical analysis techniques in the assessment of the skin barrier function after tape stripping are shown in Figure .…”

“…Information on the heterogeneity of the status and hydration of the skin barrier was obtained by imaging the skin with contact‐based capacitance sensors and by interpolating single‐point measurements to generate continuous colour maps . Another approach to offer a more thorough evaluation of the skin barrier could be to combine macroscopic assessments with biophysical analysis techniques with the assessment of molecular markers of inflammation with skin molecular diagnostic tests, such as Transdermal Analysis Patch . To understand better the aberrant lipid organization in challenged or diseased skin, information on the relation between lipid composition and organization is crucial.…”