Glabrous Skin Research Articles

Emerging Trends in Dermatophytosis among Pediatric Age Group - A View from the South

Abstract Background: Dermatophytosis is a common dermatological condition in children. Recent trends indicate increasing occurrence of dermatophytic infection in the paediatric age group and with growing anti-fungal resistance; however, more studies describing clinic-epidemiological and mycological pattern in paediatric population are needed. Aims and Objectives: The present study was undertaken to assess the clinical pattern and mycological isolates from the lesions of dermatophytosis involving the glabrous skin and to assess the association of fixed dose combinations creams with clinical and mycological pattern of cutaneous dermatophytosis. Materials and Methods: Paediatric patients (ages 1 -14) with suspected tinea infections presenting in the Department of Dermatology at a tertiary care medical college hospital in South India for a duration of four months, in 2020, were included in this study. Samples were collected and tested for potassium hydroxide (KOH) positivity. Additionally, the scales were also sent for fungal culture. Results: Out of 45 patients, 29 (64.4%) were male and 16 (35.6%) were female. The groin was the most common site affected in 89.65% patients. Around 57% of the study participants (21/45) have used corticosteroid-containing creams. Out of the 45 study participants, KOH mount was positive in 39(86.7%). Fungal Culture revealed Trichophyton mentagrophytes (55.6%) as the most common species isolated. Conclusion: Our study illustrates a major epidemiological shift of dermatophytosis causing species from Trichophyton rubrum to Trichophyton mentagrophytes among paediatric patients akin to that observed in adults. It is also observed that there is an increase in an atypical presentation owing to topical steroid use. The present study provides evidence that a high index of suspicion in needed to effectively curb the rising incidence of dermatophytosis in paediatric patients.

P255 Facial Tinea incognito: a clinical, dermoscopic, and mycological study

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PMObjectivesTinea incognito (TI) occurring on the face is the most frequently misdiagnosed cutaneous fungal infection; however, very limited information is available on facial TI. This study aimed to characterize the clinical, dermoscopic, and mycological features of facial TI.MethodsWe retrospectively evaluated 38 patients with mycologically proven facial TI at a single institution in Korea between July 2014 and July 2021.ResultsThe patients had a mean age of 59.6 ± 20.4 years and showed a slight female predominance (male-to-female ratio, 1:1.5). The most common clinical presentation was an eczema-like pattern (47.3%), followed by rosacea-like (15.7%), psoriasis-like (10.5%), lupus erythematosus-like (10.5%), cellulitis-like (7.8%), and folliculitis-like (7.8%) patterns. The mean duration from disease onset to diagnostic confirmation was 3.4 months. Overall, 78.9% of the patients had accompanying chronic systemic diseases and 57.9% had concurrent tinea infections on other skin sites, mainly on the feet and toenails. Among the 23 (60.5%) cultured specimens, Trichophyton (T.) rubrum was the most frequently detected causative species, followed by Microsporum (M.) canis. T. mentagrophytes and T. verrucosum were also isolated from one case each. On dermoscopy, scales (92.1%) and dilated vascular patterns (arborizing vessels and telangiectasia, 76.3% and 63.2%) were commonly observed in glabrous skin, with follicular patterns such as black dots, broken hairs, and empty follicles. The characteristic trichoscopic features were comma hairs, corkscrew hairs, Morse code-like hairs, and translucent hairs.ConclusionThe clinical characteristics and distinct dermoscopic features described in this article can aid in the differential diagnosis of facial TI while reducing diagnostic delays and unnecessary treatments.

P103 Role of biofilm production in recalcitrant tinea

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PMObjectiveTo determine the role of biofilm production in dermatophytic isolates from tinea infections of recalcitrant skin lesions of study patients.MethodsAn observational study conducted in UCMS and GTB Hospital Delhi, in forty clinically diagnosed and mycologically confirmed cases of recalcitrant tinea infection of glabrous skin to analyze the role of biofilm production in dermatophytes.After taking written informed consent from the study population sample collection (skin scraping) was done.The scraping was then mounted in 10% potassium hydroxide (KOH) for direct microscopic examination followed by culture on Sabouraud Dextrose Agar (SDA) media with antibiotics (Chloramphenicol, Gentamicin, Cycloheximide).The fungal growth was then subjected to LPCB mount (Lactophenol cotton blue).The isolates were allowed to form in-vitro biofilms on polystyrene microtiter plates.Quantification of biofilm biomass was done using crystal violet staining and measuring the optical density (OD) at 570 nm and classified as non-adherent/non-producer, weak moderate, and strong biofilm producers.ResultsTinea corporis and cruris were the most common clinical types of dermatophytosis. T. mentegrophytes-complex was the most common dermatophyte isolated from the clinical specimens.Majority (86.84%) of isolates formed strong (OD >4 ODc) biofilms.ConclusionThere has been an increase in the incidents of chronic and recalcitrant dermatophytosis of skin.The predominance of T. mentegrophytes-complex as observed in our study highlights the importance of the pathogen in causation of current and chronic and recalcitrant dermatophytosis in India.High rate of in-vitro strong biofilm formation by the isolates indicates that these organisms might be forming biofilms in-vivo leading to chronicity and poor response to therapy.

Remote photoplethysmography with consumer smartphone reveals temporal differences between glabrous and nonglabrous skin: Pilot in vivo study.

Photoplethysmography (PPG) is a noninvasive optical technology, with applications including vital sign extraction and patient monitoring. The PPG acquisition skin type may be of importance. Skin is either nonglabrous (~90%) or glabrous (~10%). Clinical PPG collection is typically from glabrous (fingerpad), while proliferating wearables collecting PPG, which may perform critical functions like arrythmia detection, often acquire from atypical sites. Glabrous skin has significant differences from nonglabrous, including microcirculation, yet comparisons between their PPG signals have not been well reported. Using a smartphone-based remote/contactless PPG, a pilot dataset was collected from the hands (palmar/dorsal) of five healthy volunteers. The data shows statistically significant lead time (52 ± 36 ms) of glabrous over nonglabrous. Further, a trend of glabrous amplitude increase over nonglabrous (31%) was found. Although our study has a small number of participants, these results further the characterization of PPG skin differences, and can be used to inform development of PPG-based devices.

Teaching NeuroImage: Absence of Wrinkles in Small Fiber Neuropathy.

A 48-year-old woman with clinical diagnosis of small fiber neuropathy, supported by abnormal thermal thresholds using quantitative sensory testing, underwent the water immersion wrinkling test showing lack of digital wrinkles (Figure). Normally, in the glabrous skin of the distal phalanges, water penetrates the sweat ducts provoking electrolytic changes that increase the firing of sympathetic terminals leading to vasoconstriction of the glomus bodies, generating wrinkles.1 Sympathetic fiber damage is responsible for the absence of wrinkles. This test has a sensitivity of 71% (58%–82%) and a specificity of 73% (56%–85%).2 This is a simple, noninvasive, frequently forgotten bedside test that contributes to the diagnosis of small fiber neuropathy.

Abstract P356: Cutaneous Vasodilation May Contribute To 5-ht-induced Hypotension In The Rat

5-hydroxytryptamine (5-HT, serotonin) is well-recognized to have vasodilator properties. For example, infusion of 5HT at low rates into rats decreases blood pressure acutely and chronically through reduction of total peripheral resistance. We recently showed that vasodilation in the hindquarters contributes to this fall in peripheral resistance. The hindquarter in the rat is mostly made up of skeletal muscle but also includes skin. Therefore, we hypothesized that an increase in blood flow in the skin, measured as an elevated temperature (T) in the thermoregulatory tail and paws, could contribute in part to 5-HT-induced reduction in blood pressure and hindquarters vasodilation. The temperature of thermoregulatory organs in the skin of anesthetized male, Sprague Dawley rats were measured using a Optris PI640 thermal camera. Blood pressure (from a radiotelemeter) and temperature of each paw and four locations along the tail (TL1-4) were recorded for 20 minutes before, during, and after infusion of 5-HT at a rate of 25 μg/min into the femoral vein. With this infusion protocol, the mean arterial blood pressure of rats fell over 30 mm Hg. However, the temperature of the paws (~29-32 o C) and tail (32 o at base, 25 o C at tip) were stable before and during 5-HT infusion, suggesting that flow was maintained, vs reduced, during this time. T increased during the 15-minute recovery time in all tail sections (base = from 32 o to 34 o C; tip from 23.5 o to 25.5 o C). Because the skin circulation exhibits only weak autoregulation, our results suggests that 5-HT infusion causes vasodilation of glabrous skin in the rat but without causing hyperemia. This could play a part in 5-HT induced hypotension.

Chronic Cutaneous Lupus Erythematosus in a White Population: Dermoscopic Characteristics by Clinical Subtype, Lesion Location and Disease Duration.

IntroductionChronic cutaneous lupus erythematosus (CCLE) comprises three major clinical variants: discoid lupus erythematosus (DLE), chilblain lupus erythematosus (CHLE), and lupus erythematosus profundus, also referred to as lupus erythematosus panniculitis (LEP). The aim of the current study was to systematically describe the dermoscopic features of CCLE in Polish patients with Fitzpatrick skin phototypes I–III.MethodsThe videodermoscopic images from patients with various clinical variants of CCLE (DLE, CHLE and LEP) were reviewed. Predefined parameters for dermoscopic evaluation in general dermatology were used to describe the findings in lesions located beyond the scalp. In the analysis of trichoscopic findings in lesions located on the scalp, dermoscopic features of follicular openings, hair shafts, the perifollicular surface, the interfollicular surface and vessel morphology were considered. Based on personal experience, several additional dermoscopic and trichoscopic characteristics were included in the analysis.ResultsA total of 85 lesions from 26 patients (16 women and 10 men; mean age 40.8 ± 11.2 years) were assessed. DLE on glabrous skin showed polymorphous vessels (89.1%), pink-red background (70.9%), follicular plugs (67.3%) and white scaling (58.2%), while scalp DLE was characterized by polymorphous vessels (83.3%), yellow dots (66.7%), follicular plugs (55.6%) and a reduced number of follicles (55.6%). Labial DLE (n = 2) showed linear branched and linear curved vessels, white structureless areas, red structureless (hemorrhagic) areas and red dots/globules. White scaling (61.1% vs. 34.1%; p = 0.042), gray-brown dots/globules (44.4% vs. 12.2%; p = 0.015) and peripheral pigmentation (100.0% vs. 46.2%; p = 0.036) were significantly more common in long-lasting (> 1 year) DLE lesions. CHLE (n = 5) presented with polymorphous vessels, white scales, pink-red background, red structureless areas and red dots/globules. LEP showed polymorphous vessels, white-yellow scales, follicular plugs, white structureless areas and red hemorrhagic areas.ConclusionsDermoscopy might be useful in the preliminary diagnosis of DLE, and its role in the diagnosis of CHLE and LEP needs further elucidation.

Vibrotactile Threshold Measurements at the Wrist Using Parallel Vibration Actuators

This article presents an investigation into the perceptual vibrotactile thresholds for a range of frequencies on both the inside and outside areas of the wrist when exciting the skin with parallel vibrations, realized using the L5 actuator made by Lofelt GmbH. The vibrotactile threshold of 30 participants was measured using a modified audiometry test for the frequency range of 25–1,000 Hz. The average threshold across the respective frequencies was then ultimately determined from acceleration minima. The results show that maximum sensitivity lies in the range of 100–275 Hz (peaking at 200 Hz) for the inside and 75–250 Hz (peaking at 125 Hz) for the outside of the wrist and that thresholds are overall higher for the hairy skin on the outside of the wrist than for the glabrous skin on the inside. The results also show that the vibrotactile thresholds varied highly between individuals. Hence, personalized threshold measurements at the actuator locations will be required to fine-tune a device for the user. This study is a part of an ongoing research and development project where the aim is to develop a tactile display device and a music encoding scheme with the purpose of augmenting the musical enjoyment of cochlear implant recipients. These results, along with results from planned follow-up experiments, will be used to determine the appropriate frequency range and to cast light on the dynamic range on offer for the tactile device.

Offset analgesia is increased intra‐orally

Offset analgesia (OA) is commonly used to quantify endogenous pain inhibition. However, the potential role of afferent inputs and the subsequent peripheral factors from different body areas on the underlying mechanisms are still unclear. The aim of this cross-sectional study was to compare the magnitude of OA in four different body areas representing (a) glabrous and non-glabrous skin, (b) trigeminal and extra-trigeminal areas, and (c) intra- and extra-oral tissue. OA was assessed at the oral mucosa of the lower lip, the skin of the cheek, the forearm and the palm of the hand in 32 healthy and pain-free participants. OA testing included two trials: (1) a constant trial (30 s of constant heat stimulation at an individualised temperature of Pain50 [pain intensity of 50 out of 100]) and (2) an offset trial (10s of individualised Pain50 , followed by 5s at Pain50 + 1°C and 15 s at Pain50 ). Participants continuously rated their pain during each trial with a computerised visual analogue scale. A significant OA response was recorded at the oral mucosa (p < .001, d=1.24), the cheek (p < .001, d=0.84) and the forearm (p < .001, d=1.04), but not at the palm (p=.19, d=0.24). Significant differences were shown for OA recorded at the cheek versus the mucosa (p=.02), and between palm and mucosa (p=.007), but not between the remaining areas (p > .05). This study suggests that intra-oral endogenous pain inhibition assessed with OA is enhanced and supports the role of peripheral mechanisms contributing to the OA response.

Novel temperature-controlled sleep system to improve sleep: aproof-of-concept study.

The sleep-wake cycle is regulated by circadian Process C and homeostatic Process S. Selective thermal stimulation (STS) of the cervical spine region enhances glabrous skin blood flow (GSBF) and augments body heat dissipation to increase distal-to-proximal skin gradient (DPG) causing decrease of core body temperature (CBT), which can shorten sleep onset latency (SOL) and improve sleep quality. A total of 11 young healthy/normal sleeper males challenged to go to bed (lights-off) 2 h earlier than usual were subjected in a randomised order to non-consecutive treatment and control night-time sleep sessions. The treatment night entailed activation of a dual-temperature zone mattress with a cooler centre and warmer periphery plus STS pillow that applied mild heating to the cervical spinal skin for 30 min after lights-off for sleep. During the first 30 min after lights-off, GSBF (mean [standard error (SE)] Δ=49.77[19.13]perfusion units, p=0.013) and DPG (mean [SE] Δ=2.05[0.62]°C, p= 0.005) were significantly higher and CBT (mean [SE] Δ=-0.15[0.07]°C, p=0.029) was significantly lower in the treatment than control night, while there was no significant difference in these variables during the 45 min prior to lights-off (baseline). Moreover, SOL was significantly reduced (mean [SE] Δ=-48.6[23.4]min, p=0.032) and subjective sleep quality significantly better (p < 0.001) in the treatment than control night. In conclusion, the novel sleep facilitating system comprised of the STS pillow plus dual-temperature zone mattress induced earlier increase in GSBF and DPG and earlier decline in CBT. This resulted in statistically significant shortened SOL and improved overall sleep quality, thereby reducing sleep pressure of Process S, even under the challenging investigative protocol requiring participants to go to sleep 2 h earlier than customary.

Molecular Typing of Dermatophytes Isolated from Pupils and Staff Members of Some Selected Schools in Anambra State, Nigeria

Dermatophytes are the fungal pathogens of human and animals infecting the keratinized tissues of the body namely skin, hair and nails. They include species of Trichophyton, Microsporum and Epidermophyton. This study was aimed at molecular typing of dermatophytes isolated from school pupils and staff members of some selected Schools in Anambra East and Ayamelum L.G.As of Anambra State in Nigeria. One thousand (1000) samples (scalp/hair, nail, feet, glabrous skin and groin/perianal) were collected from pupils and staff members of both gender and age bracket of (1 to 10, 11 to 20, 21 to 30 etc ) years that showed visible signs of skin infection located in these two Local Government Areas. Standard procedures were employed in processing of test samples and inoculation on dermatophyte test medium. The plates were incubated at room temperature (25 – 270C) for 7 – 10days for observation of fungal growth. Colonial, morphology, and molecular studies and sequencing were used for identification. Sensitivity was performed using sterilized discs (6mm) prepared from whatman No. 1 filter paper, impregnanted with different concentrations (25mg, 50mg, 100mg and 200mg) of terbinafine, itraconazole, ketoconazole, fluconazole and griseofulvin dissolved in 2% dimethylsuphuroxide (DMSO). Molecular studies were used as confirmatory tests on dermatophytic isolates using Sanger sequencing method. The results show that the dermatophytic isolates includes: Trichophyton tonsurans, Microsporum audounii, Trichophyton rubrum, Microsporum canis, Trichophyton violaceum, Trichophyton verrucosum, Trichophyton mentagrophytes, and Epidermorphyton flocossum. Results also revealed the nucleotide sequences of the dermatophytes and genetic relationships between isolated dermatophytes from different pupils and schools. PCR-RFLP was used as gold standard for the diagnosis and Confirmation of Source of infection of dermatophytes and can aid in initiating prompt and appropriate antifungal therapy. Phylogenetic tree was drawn to show the relationships between the isolates.

Characterization of Recalcitrant Dermatophytosis in a Multicenter Study in Sri Lanka.

A changing clinical scenario of dermatophytosis has been observed in Sri Lanka during the past few years. In keeping with the trend described in India, an increase in the number of chronic, relapsing, and recalcitrant infections has been noted. The objective of our study was to assess the therapeutic response of dermatophytosis to standard antifungal treatment in Sri Lanka and to identify possible contributory factors in cases showing inadequate therapeutic response. A descriptive, observational, cross-sectional study was carried out in nine hospitals, representing each province. Over 6 months, patients with dermatophytosis on glabrous skin were included. All subjects underwent skin scrapings for mycological studies and were treated with a standard course of antifungals for a specific period. In those patients who achieved complete clearance, recurrences were noted. The study included 796 patients, of whom 191 (24%) had symptoms for more than 3 months at presentation. A total of 519 patients (65.2%) had multiple-site involvement, and 503 (63.2%) had evidence of prior use of topical steroids. Skin scrapings were positive for fungal elements in the direct smears of 659 patients (82.8%), and the predominant dermatophyte isolated was Trichophyton mentagrophytes (65.6%). Partial responders after 10 weeks of treatment and recurrences after complete clearance were significantly greater in the group that used topical steroids before presentation (P < 0.001). This study highlights the magnitude of the threat of an inadequate therapeutic response in dermatophytosis in Sri Lanka, and identifies steroid misuse, and the shift of the predominant fungal species to T. mentagrophytes as possible causative factors.

Medial plantar artery flap

Background: The unique ability of the thick glabrous skin of the plantar heel to withstand body weight while also providing protective sensory feedback makes soft-tissue coverage of the plantar heel a particularly challenging aspect of foot reconstruction. In this study, we present the outcomes and complications associated with medial plantar artery perforator (MPAP) flap reconstruction of plantar heel. Methods: The study was a retrospective study conducted over four years, and included 22 patients with soft-tissue injury to the plantar heel. All patients underwent MPAP flap for coverage of the defect. We studied the mode of injury, defect size, flap size, duration of the procedure, complications associated with the flap and donor site, time to full weight bearing and return of protective sensation and 2-point discrimination in comparison with opposite heel. Results: We studied 22 cases with soft-tissue defects of the heel that included post-traumatic defects (7), non-healing diabetic ulcers (6), trophic ulcers (4) and post- tumor excision defects (melanoma-3, squamous cell carcinoma-2). Mean flap dimension was 24 sq.cm. 18 flaps had complete survival, while 2 flaps had necrosis of the distal edge and 2 flaps underwent complete necrosis.

Carotenoid Profiling of Yellow-Flesh Peach Fruit.

In this study, the carotenoid profiles and content in 132 cultivars of yellow-flesh peach having different fruit developmental periods (short, middle, and long), fruit surface indumenta (glabrous and pubescent skin), and flesh colors (yellow, golden, and orange) were investigated. We simultaneously analyzed and compared the levels of five carotenoids (lutein, zeaxanthin, β-cryptoxanthin, α-carotene, and β-carotene) through high-performance liquid chromatography. Large differences in carotenoid content among germplasms were observed, with coefficients of variation ranging from 21.24% to 67.78%. The carotenoid content, from high to low, was as follows: β-carotene > zeaxanthin > α-carotene > β-cryptoxanthin > lutein. We screened several varieties with high carotenoid content, including zeaxanthin in ‘Ruiguang2’, β-cryptoxanthin in ‘NJN76’ and ‘TX4F244C’, and β-carotene and total carotenoids in ‘Jintong7’, ‘77-26-7’, and ‘77-20-5’. A longer fruit developmental period was associated with greater β-carotene accumulation but lowered the zeaxanthin and β-cryptoxanthin accumulation. The zeaxanthin, β-carotene, and total carotenoid concentrations significantly increased as the flesh color deepened, but the lutein and α-carotene levels remained similar among the three flesh colors. The classification index of the indumenta significantly affected the β-carotene and total carotenoid content (p < 0.05) and was higher in pubescent than glabrous skin.

Skin and Mechanoreceptor Contribution to Tactile Input for Perception: A Review of Simulation Models.

We review four current computational models that simulate the response of mechanoreceptors in the glabrous skin to tactile stimulation. The aim is to inform researchers in psychology, sensorimotor science and robotics who may want to implement this type of quantitative model in their research. This approach proves relevant to understanding of the interaction between skin response and neural activity as it avoids some of the limitations of traditional measurement methods of tribology, for the skin, and neurophysiology, for tactile neurons. The main advantage is to afford new ways of looking at the combined effects of skin properties on the activity of a population of tactile neurons, and to examine different forms of coding by tactile neurons. Here, we provide an overview of selected models from stimulus application to neuronal spiking response, including their evaluation in terms of existing data, and their applicability in relation to human tactile perception.

Slowly-adapting type II afferents contribute to conscious touch sensation in humans: Evidence from single unit intraneural microstimulation.

Slowly‐adapting type II (SA‐II, Ruffini) mechanoreceptive afferents respond well to pressure and stretch, and are regularly encountered in human microneurography studies. Despite an understanding of SA‐II response properties, their role in touch perception remains unclear. Specific roles of different myelinated Aβ mechanoreceptive afferents in tactile perception have been revealed using single unit intraneural microstimulation (INMS), via microneurography, recording from and then electrically stimulating individual afferents. This method directly links single afferent artificial activation to perception, where INMS produces specific ‘quantal’ touch percepts associated with different mechanoreceptive afferent types. However, SA‐II afferent stimulation has been ambiguous, producing inconsistent, vague sensations, or no clear percept. We physiologically characterized hundreds of individual Aβ mechanoreceptive afferents in the glabrous hand skin and examined the subsequent percepts evoked by trains of low amplitude INMS current pulses (<10 μA). We present 18 SA‐II afferents where INMS resulted in a clear, electrically evoked sensation of large (∼36 mm2) diffuse pressure, which was projected precisely to their physiologically‐defined receptive field in the skin. This sensation was felt as natural, distinctive from other afferents, and showed no indications of multi‐afferent stimulation. Stimulus frequency modulated sensation intensity and even brief stimuli (4 pulses, 60 ms) were perceived. These results suggest that SA‐II afferents contribute to perceived tactile sensations, can signal this rapidly and precisely, and are relevant and important for computational models of touch sensation and artificial prosthetic feedback.Key points Slowly adapting type II mechanoreceptors (SA‐IIs) are primary sensory neurons in humans that respond to pressure and stretch applied to the skin.To date, no specific conscious correlate of touch has been linked to SA‐II activation.Using microneurography and intraneural microstimulation to stimulate single sensory neurons in human subjects, we find a specific sensation linked to the activation of single SA‐II afferents.This sensation of touch was reported as gentle pressure and subjects could detect this with a high degree of accuracy.Methods of artificial tactile sensory feedback and computational models of touch should include SA‐IIs as meaningful contributors to the conscious sensation of touch.

Demonstrating Hairy and Glabrous Skin Innervation in a 3D Pattern Using Multiple Fluorescent Staining and Tissue Clearing Approaches.

Skin innervation is an important part of the peripheral nervous system. Although the study of the cutaneous nerve fibers has progressed rapidly, most of the understanding of their distributional and chemical characteristics comes from conventional histochemical and immunohistochemical staining on thin tissue sections. With the development of the tissue clearing technique, it has become possible to view the cutaneous nerve fibers on thicker tissue sections. The present protocol describes multiple fluorescent staining on tissue sections at a thickness of 300 µm from the plantar and dorsal skin of rat hindfoot, the two typical hairy and glabrous skin sites. Here, the calcitonin gene-related peptide labels the sensory nerve fibers, while phalloidin and lymphatic vessel endothelial hyaluronan receptor 1 label the blood and lymphatic vessels, respectively. Under a confocal microscope, the labeled sensory nerve fibers were followed completely at a longer distance, running in bundles in the deep cutaneous layer and freestyle in the superficial layer. These nerve fibers ran in parallel to or surrounded the blood vessels, and lymphatic vessels formed a three-dimensional (3D) network in the hairy and glabrous skin. The current protocol provides a more effective approach to studying skin innervation than the existing conventional methods from the methodology perspective.

Demonstrating Hairy and Glabrous Skin Innervation in a 3D Pattern Using Multiple Fluorescent Staining and Tissue Clearing Approaches

Demonstrating Hairy and Glabrous Skin Innervation in a 3D Pattern Using Multiple Fluorescent Staining and Tissue Clearing Approaches

Dietary Bioflavanol Supplementation Does Not Improve Cold‐Induced Vasodilation in Healthy Adults

BackgroundCold‐induced vasodilation (CIVD) is a cyclical rise in blood flow to glabrous skin that occurs during cold exposure of the extremities. Nitric oxide (NO) is a proposed mediator of the CIVD response through active vasodilation and/or withdrawal of sympathetic vascular smooth muscle tone. Dietary flavanols augment bioavailable NO by upregulating NO synthase, the main source of NO in the vasculature, and by enhancing removal of reactive oxygen species that are known to breakdown NO. Although acute dietary flavanol intake has been shown to augment skin blood flow, at least in part through increased NO, no studies have examined the impact of flavanol intake on skin perfusion during cold exposure. Improving skin blood flow to the extremities may enhance manual dexterity and reduce the risk of peripheral cold injury, benefits pertinent to warfighters or other populations that spend time in cold environments.PurposeTo examine the effect of high‐dose flavanol supplementation on CIVD. We hypothesized that acute and 8‐day flavanol supplementation would augment CIVD during single‐digit cold water immersion.MethodsEleven healthy adults (24±6 yrs; 10M/1F) ingested cocoa‐based flavanols (FLV; 900 mg/d) or caffeine and theobromine‐matched placebo (PLA) for 8 days in a double‐blind, randomized, crossover design. On Days 1 and 8, CIVD was assessed 2 hours after treatment ingestion. Subjects immersed their middle finger in warm water (42°C) for 15 minutes before cold water immersion (4°C) for 30 min, during which nail bed and finger pad skin temperature were measured continuously.ResultsFlavanol ingestion had no effect (all P &gt; 0.05) on CIVD event frequency (Day 1, FLV: 3±2 vs. PLA: 3±2; Day 8, FLV: 3±2 vs. PLA: 3±1) or amplitude (Day 1, FLV: 4.3±1.7 vs. PLA: 4.9±2.6 °C; Day 8, FLV: 3.9±1.9 vs. PLA: 3.9±2.0 °C) in the finger pad following acute or 8‐day supplementation. Furthermore, average (Day 1, FLV: 9.2±1.5 vs. PLA: 9.2±1.8 °C; Day 8, FLV: 8.3±1.7 vs. PLA: 8.9±1.9 °C), maximum (Day 1, FLV: 11.9±3.0 vs. PLA: 11.2±2.3 °C; Day 8, FLV: 10.1±1.9 vs. PLA: 10.6±2.3 °C), and minimum (Day 1, FLV: 6.2±1.3 vs. PLA: 6.0±1.5 °C; Day 8, FLV: 5.8±1.8 vs. PLA: 6.2±1.7 °C) finger pad temperatures during cold water immersion were not different (all P &gt; 0.05) between treatments on Day 1 or Day 8 of supplementation. Similarly, no differences (all P &gt; 0.05) in CIVD parameters were observed in the nail bed following acute or 8‐day supplementation.ConclusionDietary ingestion of cocoa‐based flavanols does not improve the CIVD response to single‐digit cold water immersion.

Antihistamine promotes electroacupuncture analgesia in healthy human subjects: A pilot study

Background and aimWe have previously reported that histamine H1 receptor antagonists facilitate electroacupuncture (EA) analgesia in experimental animals. In this pilot study, we sought to determine whether the histamine H1 receptor antagonist dexchlorpheniramine (DCPA) facilitates EA analgesia in healthy human subjects. Experimental procedureForty healthy subjects aged 20–30 years were randomly allocated to 1 of 4 groups: (1) sham EA at acupoints Zusanli (ST36) and Yanglingquan (GB34) (sham EA; n = 10); (2) EA at ST36 and GB34 (n = 10); (3) EA at ST36 and GB34 plus low-dose DCPA (2 mg, n = 10); (4) EA at ST36 and GB34 plus high-dose DCPA (4 mg, n = 10). Before and after acupuncture treatment, pain thresholds were determined by transcutaneous electrical stimuli on the glabrous skin of the left upper arm. ResultsAfter the acupuncture session, subjects in the EA plus high-dose DCPA group had a significantly higher pain threshold elevation compared with the other 3 study groups. The change from baseline in pain threshold in the EA plus high-dose DCPA group was significantly greater than the change in pain threshold with EA only, indicating that DCPA 4 mg facilitated EA analgesia. ConclusionThe results suggest that combining H1 receptor antagonist treatment with EA appears to relieve pain to a greater extent compared with EA alone. This study is registered with ClinicalTrials.gov (https://clinicaltrials.gov/), number NCT03805035 (https://clinicaltrials.gov/ct2/show/NCT03805035).