Actual Skin Research Articles

Comparison of predicted and actual dermatitis generated from computed tomography images and dose distribution maps

Anticipating the onset, location and severity of radiation dermatitis before radiotherapy can aid in dermatological care. This study developed a method for creation of a prediction diagram for dermatitis and conducted a comparative verification between the prediction diagram and actual patient condition. The prediction diagram involved converting skin doses into 2 Gy fractionated equivalent doses using α/β of 10.0, defining regions of interest (ROIs) from 20-50 Gy at 10 Gy intervals. Overlaps between these ROIs at each dose level and the skin (external) was sequentially color-coded as blue, yellow, red, and purple. The study included four patients: two underwent head and neck treatment and two received neck and chest treatment. This approach involved a visual assessment comparing the prediction diagram with skin photographs captured at the end of treatment. Nurses marked skin sites corresponding to grades 1 and 2 on photographs, assessing their correlation with the predicted range. Visual assessment results were largely positive, although one patient exhibited slightly lower scores. Results revealed a correlation between grade 1 skin reactions and the 20 Gy regions. Grade 2 reactions were observed in regions near 30 and 40 Gy. Although discrepancies between prediction diagram and actual skin symptoms were observed in patients, a broad agreement was evident. The prediction diagram cannot accurately predict radiation dermatitis, as it does not account for skin symptoms unrelated to the dose. However, the diagram is significant as it provides physicians, nurses, and patients with concise and visually comprehensible information regarding the location of dermatitis.

Anti-aging potential of Cephalotaxus harringtonia extracts: the role of harringtonine and homoharringtonine in skin protection

Photoaging damages the skin layers. The tumor necrosis factor-alpha (TNF-α) plays a crucial role in the central mechanism of photoaging. TNF-α production leads to direct damage to skin cells and facilitates the degradation of vital extracellular matrix (ECM) proteins. TNF-α stimulates matrix metalloproteinase-1 (MMP-1) activation This accelerates the loss of skin elasticity and wrinkle formation. Thus, preventing photoaging and delaying the skin aging process are important research objectives, and the development of new anti-aging substances that target the TNF-α and MMP-1 pathways is promising. In this context, the efficacies of four extracts derived from two types of Cephalotaxus harringtonia (CH) buds (CH-10Y-buds, CH-200Y-buds) and leaves (CH-10Y-leaves, CH-200Y-leaves) were investigated, exhibiting a significant reduction in reactive oxygen species (ROS). Among the four extracts, CH-10Y-buds was the most effective in reducing ROS and exhibited the highest amounts of harringtonine and homoharringtonine. The activities of harringtonine, homoharringtonine, and ginkgetin were evaluated; harringtonine exhibited a high efficacy in inhibiting TNF-α-induced inflammatory responses and MMP-1 activation, thereby reducing collagen degradation. These findings suggest that CH-10Y-buds and their components herringtonin are promising candidates for preventing damage caused by photoaging. Our results can facilitate the development of new methods for maintaining skin health and inhibiting the skin aging process. Further research is necessary to comprehensively evaluate the potential efficacy of these candidate substances and investigate their applicability to actual skin. Such studies will aid in the development of more effective anti-aging strategies in the future.

The intersection-of-asymptotes method applied to the study of skin temperature changes over time during running exercise

The intersection of asymptotes method is used to describe the changes in skin temperature of the human body during running exercise. Skin temperature variations are induced by thermoregulatory mechanisms, which are influenced by both physiological and environmental factors. The aim of this study is to succinctly and comprehensively connect these factors to create an easily interpretable tool for understanding this process. Based on simplified energy balance equations under dynamic conditions for both the early and late stages of exercise, two asymptotic solutions for skin temperature are derived. The point of intersection between these solutions determines the moment at which the transition from skin vasoconstriction to vasodilation occurs. The shapes and the intersection of the two asymptotes enable the inference and interpretation of actual skin temperature variations throughout the course of exercise.

Lipid Nanoparticle-Mediated Hit-and-Run Approaches Yield Efficient and Safe In Situ Gene Editing in Human Skin.

Despite exciting advances in gene editing, the efficient delivery of genetic tools to extrahepatic tissues remains challenging. This holds particularly true for the skin, which poses a highly restrictive delivery barrier. In this study, we ran a head-to-head comparison between Cas9 mRNA or ribonucleoprotein (RNP)-loaded lipid nanoparticles (LNPs) to deliver gene editing tools into epidermal layers of human skin, aiming for in situ gene editing. We observed distinct LNP composition and cell-specific effects such as an extended presence of RNP in slow-cycling epithelial cells for up to 72 h. While obtaining similar gene editing rates using Cas9 RNP and mRNA with MC3-based LNPs (10-16%), mRNA-loaded LNPs proved to be more cytotoxic. Interestingly, ionizable lipids with a pKa ∼ 7.1 yielded superior gene editing rates (55%-72%) in two-dimensional (2D) epithelial cells while no single guide RNA-dependent off-target effects were detectable. Unexpectedly, these high 2D editing efficacies did not translate to actual skin tissue where overall gene editing rates between 5%-12% were achieved after a single application and irrespective of the LNP composition. Finally, we successfully base-corrected a disease-causing mutation with an efficacy of ∼5% in autosomal recessive congenital ichthyosis patient cells, showcasing the potential of this strategy for the treatment of monogenic skin diseases. Taken together, this study demonstrates the feasibility of an in situ correction of disease-causing mutations in the skin that could provide effective treatment and potentially even a cure for rare, monogenic, and common skin diseases.

EVALUASI DOSE-AREA PRODUCT DAN WAKTU FLUOROSKOPI SEBAGAI METRIK DOSIS PADA AUDIT DOSIS PROSEDUR FLUOROSKOPI INTERVENSIONAL: STUDI MULTISENTER

This study aims to evaluate conventional dose metrics, namely Dose-Area Product (DAP) and fluoroscopy time, commonly used in interventional fluoroscopy procedure dose audits, by comparing them to a dose metric that more closely represents the dose at the patient's skin, namely Entrance Surface Dose (ESD). The research was conducted by first calculating the ESD using AndroidTM-based software from a previous study (Mulia et al., 2020) with retrospective data from 2 (two) hospitals (20 patients each) that utilized the Philips Allura XPer FD20 interventional fluoroscopy system. The results showed that DAP and fluoroscopy time did not exhibit a linear correlation with the skin dose represented by ESD, with R2 values of 0.11 for Hospital A and 0.79 for Hospital B. Consequently, the DAP and fluoroscopy time dose metrics were deemed insufficient in representing the actual skin dose received by the patients. This study recommends medical physicists also include ESD calculations and utilize them in radiation dose audits as supplementary data to monitor patient deterministic effects directly. Keywords: skin dose, kerma, DAP, dose, interventional

The Unreasonable Effectiveness of Reaction Diffusion in Vertebrate Skin Color Patterning.

In 1952, Alan Turing published the reaction-diffusion (RD) mathematical framework, laying the foundations of morphogenesis as a self-organized process emerging from physicochemical first principles. Regrettably, this approach has been widely doubted in the field of developmental biology. First, we summarize Turing's line of thoughts to alleviate the misconception that RD is an artificial mathematical construct. Second, we discuss why phenomenological RD models are particularly effective for understanding skin color patterning at the meso/macroscopic scales, without the need to parameterize the profusion of variables at lower scales. More specifically, we discuss how RD models (a) recapitulate the diversity of actual skin patterns, (b) capture the underlying dynamics of cellular interactions, (c) interact with tissue size and shape, (d) can lead to ordered sequential patterning, (e) generate cellular automaton dynamics in lizards and snakes, (f) predict actual patterns beyond their statistical features, and (g) are robust to model variations. Third, we discuss the utility of linear stability analysis and perform numerical simulations to demonstrate how deterministic RD emerges from the underlying chaotic microscopic agents.

Skin quality sensor to evaluate vibration and friction generated when sliding over skins.

The mechanical condition and tactile evaluation of skin are essential for the development of skin care products. Most of the existing commercial instruments and studies aim to evaluate the skin surface by pressing it for hardness or by using imaging sensors, but there have been few instrumental measurements employing rubbing motion. Here, we have developed a sensor specialized for tactile sensation and the contact phenomenon during skin rubbing. The developed sensor has three features: It can measure body parts including cheeks and arms, automate the rubbing motion of the probe and measure vibration and friction simultaneously. It is hand-held, with metal probes that rub the skin surface while rotating under a motor drive; it has an accelerometer and a force sensor beneath the probe measuring vibration and friction forces. To evaluate the validity of the sensor's measurements, artificial skin models were measured using the developed sensor and commercially available sensors and the results were compared. The relationship between the sensor output, surface roughness measurement and sensory evaluation was also investigated. Additionally, we evaluated the inter-rater reliability when measuring actual skin. The measurements of five artificial skin models with different surface shapes showed a high correlation (r = 0.99) between the vibration intensity values evaluated by the developed sensor and those measured by a tri-axial acceleration sensor attached to a fingernail. The correlation coefficient between the vibration intensity values and surface roughness was r = 0.91, and the correlation with the sensory evaluation score of roughness was r = 0.99. The friction coefficients measured by the developed sensor and the force plate had r = 0.93, based on measurements of five artificial skin models with different friction conditions. The inter-rater correlation coefficients between the three participants of the developed sensor were as high as 0.92 and 0.94 for the vibration and friction measurements respectively. The vibration intensities and friction coefficients from the sensor were highly correlated with those of the conventional sensor. The inter-rater reliability was also high. The developed sensor can be useful for tactile evaluation in skin-care product development.

Colorism attitudes and use of skin lightening agents in the United States.

In this study, we examine SL habits, including both general lightening and lightening for the treatment of a skin condition, among SOC individuals in the United States and the role of colorism in motivating these behaviors. A cross-sectional survey was administered to SOC individuals through ResearchMatch, an online national health registry. Demographics, rates of SL, SL habits, and perceived colorism among SL users and nonusers were collected and analyzed with χ2, Fisher's exact, Analysis of variance (ANOVA), Spearman correlation, and t tests. A total of 455 participants completed the survey. Ninety-seven participants (21.3%) reported using SL agents: 73.2% (71/97) used SL agents for the treatment of a skin condition and 26.8% (26/97) used the products for general SL. Only 22.6% (22/97) of SL users consulted a medical provider before using the products. Forty-four participants (45.4%) were unaware of their SL product ingredients, and 35.1% (34/97) reported using hydroquinone-based products. Composite colorism scores were significantly higher in SL users than nonusers (20.03 vs 18.20; P < .001). This study used self-reported racial/ethnic groups to characterize those with SOC rather than assessing actual skin tones of participants, which could have led to variability. SL among SOC individuals is prevalent in the U.S. and poses a health risk, as many SL users are unaware of product ingredients, do not consult a medical provider before use, and have access to potentially unsafe formulations. Dermatologists should address skin tone and pigmentary concerns with their SOC patients.

External Validation of the Skin and UV Neoplasia Transplant Risk Assessment Calculator (SUNTRAC) in a Large European Solid Organ Transplant Recipient Cohort

The Skin and UV Neoplasia Transplant Risk Assessment Calculator (SUNTRAC) tool has been developed in the US to facilitate the identification of solid organ transplant recipients (SOTRs) at a higher risk of developing skin cancer. However, it has not yet been validated in populations other than the one used for its creation. To provide an external validation of the SUNTRAC tool in different SOTR populations. This retrospective external validation prognostic study used data from a prospectively collected cohort of European SOTRs from transplant centers at teaching hospitals in the Netherlands (1995-2016) and Spain (2011-2021). Participants were screened and followed up at dermatology departments. Data were analyzed from September to October 2021. The discrimination ability of the SUNTRAC tool was assessed via a competing risk survival analysis, cumulative incidence plots, and Wolbers concordance index. Calibration of the SUNTRAC tool was assessed through comparison of projected skin cancer incidences. Skin cancer diagnoses included squamous cell carcinoma, basal cell carcinoma, melanoma, and Merkel cell carcinoma. A total of 3421 SOTRs (median age at transplant, 53 [quartile 1: 42; quartile 3: 62] years; 2132 [62.3%] men) were assessed, including 72 Asian patients (2.1%), 137 Black patients (4.0%), 275 Latinx patients (8.0%), 109 Middle Eastern and North African patients (3.2%), and 2828 White patients (82.7%). With a total of 23 213 years of follow-up time, 603 patients developed skin cancer. The SUNTRAC tool classified patients into 4 groups with significantly different risks of developing skin cancer during follow-up. Overall, the relative rate for developing skin cancer estimated using subdistribution hazard ratios (SHRs) and using the low-risk group as the reference group, increased according to the proposed risk group (medium-risk group: SHR, 6.8 [95% CI, 3.8-12.1]; P < .001; high-risk group: SHR, 15.9 [95% CI, 8.9-28.4]; P < .001; very-high-risk group: SHR, 54.8 [95% CI, 29.1-102.9]; P < .001), with a concordance index of 0.72. Actual skin cancer incidences were similar to those predicted by the SUNTRAC tool (5-year skin cancer cumulative incidence for medium-risk group: predicted, 6.2%; observed, 7.0%). The findings of this external validation prognostic study support the use of the SUNTRAC tool in European populations for stratifying SOTRs based on their skin cancer risk and also detecting patients at a high risk of developing skin cancer. This can be helpful in prioritizing and providing better screening and surveillance for these patients.

Characterisation of composite skin–stiffener bonding interface and fine-defect evaluation using mono-pulse ultrasonic detection

A mono-pulse ultrasonic (MU)-based detection method was developed for the detailed characterisation of the carbon-fibre skin–stiffener bonding interface and the quantitative evaluation of the fine defects therein. Specimens exhibiting artificial defects and actual skin–stiffener components were used as test specimens. A MU experimental system was constructed. Experiments were performed to elucidate reflection behaviour and signal and morphological characteristics of skin–stiffener joints, and the microstructural morphologies were compared. Defect detectability was experimentally studied at different sample depths. The results showed that the reflected-signal pulse width was ∼1 period. The ultrasonic dead zone reached a single pre-preg-ply thickness (∼ 0.125 mm). The de-lamination, de-bonding, adhesive and resin layers, and changes in the bonding-interface layup, were well determined. The minimum and maximum deviations of the detected-defect sizes were ∼ 0.0 and 1.0 mm, respectively. The de-lamination depth-positioning deviation was < 0.5 of a pre-preg ply.

Skin tone preferences and their influence on skin care behaviors.

Knowledge regarding skin tone preferences and their influence on skincare behaviors among people of color is limited. The objective of this study was to determine whether there is a difference between ideal and actual skin tone among people of color and whether this difference is associated with tanning and sunscreen use. This was a one-time, voluntary, anonymous, electronic survey designed in REDCap and delivered through ResearchMatch, a national electronic, recruitment tool. Eligible participants were at least 18years old and self-identified as Black, Asian, Latinx, American Indian/Alaskan Native or Mixed Race. In total, 548 completed survey results were analyzed using SAS. Only the Latinx population was found to have a significant preference for tanner skin (p < 0.05). The Latinx population had significantly more subjects that participated in outdoor tanning than both the Black (p < 0.0001) and Asian population (p < 0.05). Latinx participants who indicated a preference for tanner skin were 2.8 times more likely to never use sunscreen than those without this preference (OR = 2.821, CI = 1.029-7.732, p < 0.05). Our findings have implications for how dermatologists screen, treat, and educate Latinx and skin of color populations.

Comparison of Prospectively Generated Glioma Treatment Plans Clinically Delivered on Magnetic Resonance Imaging (MRI)-Linear Accelerator (MR-Linac) Versus Conventional Linac: Predicted and Measured Skin Dose.

Introduction: Magnetic resonance imaging-linear accelerator radiotherapy is an innovative technology that requires special consideration for secondary electron interactions within the magnetic field, which can alter dose deposition at air–tissue interfaces. As part of ongoing quality assurance and quality improvement of new radiotherapy technologies, the purpose of this study was to evaluate skin dose modelled from the treatment planning systems of a magnetic resonance imaging-linear accelerator and a conventional linear accelerator, and then correlate with in vivo measurements of delivered skin dose from each linear accelerator. Methods: In this prospective cohort study, 37 consecutive glioma patients had treatment planning completed and approved prior to radiotherapy initiation using commercial treatment planning systems: a Monte Carlo-based algorithm for magnetic resonance imaging-linear accelerator or a convolution-based algorithm for conventional linear accelerator. In vivo skin dose was measured using an optically stimulated luminescent dosimeter. Results: Monte Carlo-based magnetic resonance imaging-linear accelerator plans and convolution-based conventional linear accelerator plans had similar dosimetric parameters for target volumes and organs-at-risk. However, magnetic resonance imaging-linear accelerator plans had 1.52 Gy higher mean dose to air cavities (P < .0001) and 1.10 Gy higher mean dose to skin (P < .0001). In vivo skin dose was 14.5% greater for magnetic resonance imaging-linear accelerator treatments (P = .0027), and was more accurately predicted by Monte Carlo-based calculation (ρ = 0.95, P < .0001) versus convolution-based (ρ = 0.80, P = .0096). Conclusion: This is the first prospective dosimetric comparison of glioma patients clinically treated on both magnetic resonance imaging-linear accelerator and conventional linear accelerator. Our findings suggest that skin doses were significantly greater with magnetic resonance imaging-linear accelerator plans but correlated better with in vivo measurements of actual skin dose from delivered treatments. Future magnetic resonance imaging-linear accelerator planning processes are being designed to account for skin dosimetry and treatment delivery.

Estimation of reflectance, transmittance, and absorbance of cosmetic foundation layer on skin using translucency of skin.

We developed a method to estimate the reflectance, transmittance, and absorbance of a layer of cosmetic foundation (FD) applied to skin from the reflectance of bare skin and FD applied to skin under two measurement conditions using the translucency of skin. Conversely, using the relationship between the applied amount of FD and the reflectance of the FD layer, the applied amount could be estimated. These values could be measured stably regardless of the similarity of reflectance and color between bare skin and made-up skin. The measured values were taken from actual skin, which satisfies the condition of actual usage.

Determination of geometric information and radiation field overlaps on the skin in percutaneous coronary interventions with computer-aided design-based X-ray beam modeling.

PurposeThis study aimed to develop a method for the determination of the source‐to‐surface distance (SSD), the X‐ray beam area in a plane perpendicular to the beam axis at the entrance skin surface (Ap ), and the X‐ray beam area on the actual skin surface (As ) during percutaneous coronary intervention (PCI).Materials and MethodsMale and female anthropomorphic phantoms were scanned on a computed tomography scanner, and the data were transferred to a commercially available computer‐aided design (CAD) software. A cardiovascular angiography system with a 200 × 200 mm flat‐panel detector with a field‐of‐view of 175 × 175 mm was modeled with the CAD software. Both phantoms were independently placed on 40 mm thick pads, and the examination tabletop at the patient entrance reference point. Upon panning, the heart center was aligned to the central beam axis. The SSD, Ap , and As were determined with the measurement tool and Boolean intersection operations at 10 gantry angulations.ResultsThe means and standard deviations of the SSD, Ap , and As for the male and female phantoms were 573 ± 15 and 580 ± 15 mm, 8799 ± 1009 and 9661 ± 1152 mm2, 10495 ± 602 and 11913 ± 600 mm2, respectively. The number of As overlaps for the male and female phantoms were 15/45 and 21/45 view combinations, respectively.ConclusionsCAD‐based X‐ray beam modeling is useful for the determination of the SSD, Ap , and As . Furthermore, the knowledge of the As distribution helps to reduce the As overlap in PCI.

A study on the capacity of a ventilation cooling vest with pressurized air in hot and humid environments

Hot and humid working environments exist in civil engineering, exploration, shipping, and so on. Especially in mines and textile workplaces, the air humidity is usually close to saturation. Frontline workers perform physically demanding work, which will make the body sweat greatly and increase the occurrence of heat-related illnesses. The microenvironment under clothing can be improved by a ventilation cooling vest with pressurized air (denoted VCV), and the trunk skin temperature will be decreased. However, the amount of heat that a VCV removes from a working human body in hot and humid environments is unclear. In this study, human experiments were carried out, the ambient temperature was controlled at 30 °C, 32 °C or 34 °C, and the air humidity was 90%. The subjects wore a labor suit (denoted LS) or a VCV, running on a treadmill at 5 km/h or 7.5 km/h. The results showed that the total trunk heat loss was increased by 169–237%, and the cooling power of the VCV was between 79.5 and 97.6 W when wearing the VCV. However, the actual skin wettedness is often less than the calculated value, and the calculated cooling power should be considered the upper limit. The study indicated that the cooling capacity of the VCV increased as the ambient temperature and labor intensity increased, and the heat dissipation of the body also increased.

Dose Setting for Dermal Absorption Studies on Dried Foliar Residues.

Currently, the standard approach to estimate systemic exposure of workers after contact with dried pesticide residues on crops during re-entry activities relies on using the highest identified dermal absorption value for aqueous spray dilutions. However, recent dermal absorption studies with dried residues and their respective in-use dilutions have shown that this is likely to significantly overestimate their dermal penetration potential and, thus, predicted systemic exposure. The choice of appropriate dose levels for these dermal absorption studies has not been defined. Moreover, actual skin loading during re-entry tasks may differ significantly from that achieved by applying a fixed volume of an aqueous dilution, which is the standard practice in generic dermal absorption studies. To address this, we propose an approach to dose setting for dried residue studies within the current European risk assessment framework. Skin loading for studies can be calculated from the existing exposure algorithms and by taking appropriate body surface areas into account. Thus, skin loading in studies will vary depending on the exact nature and duration of the task and the region of the body exposed, reflecting actual exposure scenarios.

A novel camera colour characterisation model for the colour measurement of human skin

Accurate facial skin colour representation is highly required for an increasing number of applications, such as the solution of cosmetic products, the diagnosis of cutaneous diseases, and the manufacture of soft tissue prostheses. This study presents a novel camera colour characterisation model with higher predictive accuracy for the image-based colour measurement of human skin. More specifically, a digital imaging system was developed to collect the facial images of sixty human subjects from four ethnic groups. The newly collected human facial skin colour data and a conventional colour chart were selected as the training dataset, respectively, and three general techniques (linear transformation, polynomial regression, and root-polynomial regression) were utilised to derive the characterisation model by mapping camera digital signals to CIE XYZ tristimulus values. The predictive accuracy of each model was then verified using the mean CIELAB colour difference between actual skin colour measurements and the corresponding predictions from colour images. Results showed that the best model performance was achieved when the human skin colours of real subjects were used as the training samples and first order polynomial regression was used as the mapping algorithm.

Changes in facial moisture distribution and feelings of moisture/dryness among various environmental temperatures and humidities in summer and winter.

As environmental conditions vary depending on area of residence, consideration of environmental temperature and humidity conditions is crucial for detection of actual skin conditions in daily life. In this study, we determined changes in facial moisture and sensory evaluation distributions in various environmental temperature and humidity conditions. An original near-infrared (NIR) imaging system was used to obtain moisture distributions. Sensory evaluations of feelings of moisture/dryness were graded, and changes were compared among 10 healthy Japanese female subjects in four different environmental temperature and humidity conditions (28°C, 60% RH; 28°C, 20% RH; 15°C, 60% RH; 15°C, 20% RH) in summer and winter. Skin moisture was lower at high temperatures and higher at low temperatures. Feelings of dryness on bare skin were high in low humidity. Sensitivity of feelings of moisture and dryness was high around the center of the cheekbones between side of the eyes and the mouth, but the same was not true of the moisture distribution. Moisture level was lower in winter at high temperatures, especially under the eyes near the side of the nose ridge, while the sense of dryness was not strong. These divergences between sensory evaluation and moisture level indicate the presence of a "hidden dry situation." Changes in moisture level and sensory evaluation scores in facial skin varied among environmental conditions, which differed between summer and winter, even under the same environmental temperature and humidity.

Increased skin wetness independently augments cool‐seeking behaviour during passive heat stress

Skin wetness occurring secondary to the build-up of sweat on the skin provokes thermal discomfort, the precursor to engaging in cool-seeking behaviour. Associative evidence indicates that skin wetness stimulates cool-seeking behaviour to a greater extent than increases in core and mean skin temperatures. The independent contribution of skin wetness to cool-seeking behaviour during heat stress has never been established. We demonstrate that skin wetness augments cool-seeking behaviour during passive heat stress independently of differential increases in skin temperature and core temperature. We also identify that perceptions of skin wetness were not elevated despite increases in actual skin wetness. These data support the proposition that afferent signalling from skin wetness enhances the desire to engage in cool-seeking behaviour during passive heat stress. This study tested the hypothesis that elevations in skin wetness augments cool-seeking behaviour during passive heat stress. Twelve subjects (6 females, age: 24±2 y) donned a water-perfused suit circulating 34°C water and completed two trials resting supine in a 28.5±0.4°C environment. The trials involved a 20min baseline period (26±3% relative humidity (RH)), 60min while ambient humidity was maintained at 26±3% RH (LOW) or increased to 67±5% RH (HIGH), followed by 60min passive heat stress (HS) where the water temperature in the suit was incrementally increased to 50°C. Subjects were able to seek cooling when their neck was thermally uncomfortable by pressing a button. Each button press initiated 30s of -20°C fluid perfusing through a custom-made device secured against the skin on the dorsal neck. Mean skin (Tskin ) and core (Tcore ) temperatures, mean skin wetness (Wskin ) and neck device temperature (Tdevice ) were measured continuously. Cool-seeking behaviour was determined from total time receiving cooling (TTcool ) and cumulative button presses. Tskin and Tcore increased during HS (P<0.01) but were not different between conditions (P≥0.11). Wskin was elevated in HIGH vs. LOW during HS (60min: by +0.06±0.07 a.u., P≤0.04). Tdevice was lower in HIGH vs. LOW at 40-50min of HS (P≤0.01). TTcool was greater for HIGH (330±172s) vs. LOW (225±167s, P<0.01), while the number of cumulative button presses was greater from 40-60min in HS for HIGH vs. LOW (P≤0.04). Increased skin wetness amplifies the engagement in cool-seeking behaviour during passive heat stress.

Increasing Warmth in Adolescents with Anorexia Nervosa: A Randomized Controlled Crossover Trial Examining the Efficacy of Mustard and Ginger Footbaths.

Objective To analyze the thermogenic effects of footbaths with medicinal powders in adolescents with anorexia nervosa (AN) in comparison to healthy controls (HCs). Intervention and Outcomes. Forty-one female participants (21 AN, 20 HCs; 14.22 ± 1.54 years) received three footbaths—warm water and mustard (MU, Sinapis nigra), warm water and ginger (GI, Zingiber officinale), or warm water only (WA), in random order within a crossover design. Data were collected before (t1), immediately after foot immersion (maximum 20 minutes) (t2), and after 10 minutes subsequently (t3). Actual skin temperature (high resolution thermography) and perceived warmth (HeWEF questionnaire) were assessed at each time point for various body parts. The primary outcome measure was self-perceived warmth at the feet at t3. Secondary outcome measures were objective skin temperature and subjective warmth at the face, hands, and feet. Results Perceived warmth at the feet at t3 was significantly higher after GI compared to WA (mean difference −1.02) and MU (−1.07), with no differences between those with AN and HC (−0.29). For the secondary outcome measures, a craniocaudal temperature gradient for the skin temperature (thermography) was noted at t1 for patients with AN and HC (AN with colder feet). The craniocaudal gradient for subjective warmth was only seen for patients with AN. Conclusion Footbaths with ginger increased warmth perception at the feet longer than with mustard or warm water only for adolescents with AN as well as for HC. The impact of ginger footbaths on recovery of thermoregulatory disturbances in patients with AN repeated over extended periods merits further investigation.