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Hematidrosis is a disorder in which blood-tinged fluid exudes from uninjured skin or mucosa. It is often classified as an eccrine sweat disorder, though the precise mechanism-including involvement of sweat glands-has yet to be proven. In contemporary case reports, hematidrosis appears most frequently in the pediatric population, with 83% of cases in the literature since 2008 occurring in individuals 18 years old or younger. We present here a case of a 10-year-old girl with hematidrosis followed by a review of the literature, with an emphasis on the features of this condition in the pediatric population.

Background Sweat gland function deteriorates with aging, leading to loss of heat tolerance. However, it is unclear whether and how the structure of sweat glands changes during aging, because the 3D structure is complex and inaccessible. Methods To clarify age‐dependent changes in sweat glands, we developed a method for 3D structure analysis of sweat glands by means of X‐ray micro‐CT observation of human skin specimens followed by 3D digital reconstruction on computer (digital 3D skin). Results Comparison of eccrine sweat glands of abdominal skin from young and old subjects showed that the density and volume of sweat glands do not change with aging. In contrast, the depth of the secretory coil from the skin surface is decreased in the aged group. Surprisingly, the secretory ducts appear tortuous or meandering though their length is unchanged. The secretory coils are located at the dermal‐adipose layer boundary in both groups, but the thickness of the dermal layer decreases with aging, and the depth of the coils is correlated with the dermal thickness. Conclusion Our results suggest that sweat glands twist and rotate with aging to maintain the position of the coil at the dermal‐adipose boundary, causing an overall shift toward the skin surface.

As a result of physiological thermoregulation, human eccrine sweat glands produce sessile droplets on the skin. This paper studies the thermal signatures associated with droplet dynamics on the fac...

The contribution of nitric oxide synthase (NOS) to the process of cholinergic-mediated human eccrine sweat production is unclear. Using a novel model for cholinergic-mediated sweating in humans, I demonstrate that blocking the NOS system led to a reduction in local sweat rate (LSR). This reduction in LSR was maintained in the presence of K+ channel blockade with tetraethylammonium.

PurposeLive non-invasive monitoring of biomarkers is of great importance for the medical community. Moreover, some studies suggest that there is a substantial business gap in the development of mass-production commercial sweat-analysing wearables with great revenue potential. The objective of this work is to quantify the concentration of biomarkers that reaches the area of the garment where a sensor is positioned to advance the development of commercial sweat-analysing garments.Design/methodology/approachComputational analysis of the microfluidic transport of biomarkers within eccrine sweat glands provides a powerful way to explore the potential for quantitative measurements of biomarkers that can be related to the health and/or the physical activity parameters of an individual. The numerical modelling of sweat glands and the interaction of sweat with a textile layer remain however rather unexplored. This work presents a simulation of the production of sweat in the eccrine gland, reabsorption from the dermal duct into the surrounding skin and diffusion within an overlying garment.FindingsThe model represents satisfactorily the relationship between the biomarker concentration and the flow rate of sweat. The biomarker distribution across an overlying garment has also been calculated and subsequently compared to the minimum amount detectable by a sensor previously reported in the literature. The model can thus be utilized to check whether or not a given sensor can detect the minimum biomarker concentration threshold accumulated on a particular type of garment.Originality/valueThe present work presents to the best of our knowledge, the earliest numerical models of the sweat gland carried out so far. The model describes the flow of human sweat along the sweat duct and on to an overlying piece of garment. The model considers complex phenomena, such as reabsorption of sweat into the skin layers surrounding the duct, and the structure of the fibres composing the garment. Biomarker concentration maps are obtained to check whether sensors can detect the threshold concentration that triggers an electric signal. This model finds application in the development of smart textiles.

Eccrine poroma is a benign adnexal tumour, which originates from the acrosyringium of eccrine sweat glands. Eccrine poroma is an uncommon neoplasm, the typical clinical presentation of which is a solitary soft sessile reddish papule protruding from a cup-shaped shallow depression. Many challenges remain in the diagnosis of eccrine poroma because it does not always present with classical features and may mimic any other cutaneous benign and malignant lesions. Eccrine poromas may occur on any skin surface with sweat glands; on the other hand, the most common sites of involvement include the palms and soles, which are rich in eccrine sweat glands. Here, we present a case of subungual eccrine poroma, which is an extremely rare presentation of poromas. We also highlight dermoscopic features of eccrine poroma and review the available literature on the subject.

Cholinergic-activated sweating depends on an influx of Ca2+ from extracellular fluid. It is thought that the opening of K+ channels on secretory epithelial cells facilitates Ca2+ entry. We examined the hypothesis that tetraethylammonium (TEA)-sensitive K+ channels participate in sweat production. We used a pre-post experimental design and initiated cholinergic-mediated sweating with intradermal electrical stimulation, monitored local sweat rate (SR) with a small sweat capsule mounted on the skin, and delivered 50 mM TEA via intradermal microdialysis. Local SR was activated by intradermal stimulation frequencies of 0.2–64 Hz, and we generated a sigmoid-shaped stimulus-response curve by plotting the area under the SR-time curve versus log10 stimulus frequency. Peak local SR was reduced from 0.372 ± 0.331 to 0.226 ± 0.190 mg·min−1·cm−2 ( P = 0.0001) during application of 50 mM TEA, whereas the EC50 and Hill slopes were not altered. The global sigmoid-shaped stimulus-response curves for control and 50 mM TEA were significantly different ( P < 0.0001), and the plateau region was significantly reduced ( P = 0.0023) with the TEA treatment. The effect of TEA on peak local SR was similar in male and female subjects. However, we did note a small effect of sex on the shape of the stimulus-response curves during intradermal electrical stimulation. Overall, these data support the hypothesis that cholinergic control of sweat gland activity is modulated by the presence of TEA-sensitive K+ channels in human sweat gland epithelial cells. NEW & NOTEWORTHY The contribution of various potassium channels to the process of cholinergic-mediated human eccrine sweat production is unclear. Using a novel model for cholinergic-mediated sweating in humans, we provide evidence that tetraethylammonium-sensitive K+ channels (KCa1.1 and Kv channels) contribute to eccrine sweat production.

Digital papillary adenocarcinoma (DPA) is a rare and aggressive tumor arising from the eccrine sweat glands. It is found on the hands and feet and most commonly occurs on the volar and distal finger tips. In this report, we describe a DPA in a 45-year-old woman who presented with a slowly enlarging mass on the dorsal aspect of her proximal ring finger. This report shows that DPA may clinically present as a relatively benign-appearing mass and in an atypical location. Surgical excision, followed by histologic and immunohistochemical evaluations of even benign-appearing digital masses, is important because this is the only way a DPA can be diagnosed.

In this paper, we present the use of smart eyewear as reading glasses and as non-intrusive sensing devices that can measure the electrodermal activity (EDA) of readers of fiction in real-time using electrodes on the forehead. EDA has seen extensive use in the past decade in accessing emotional arousal, with research linking human skin sweating to the emotional state of a subject. Traditional ways of measuring EDA involve using the fingers, which has the highest concentration of eccrine sweat glands, but this method proves to be intrusive in non-laboratory environments as most daily activities require the use of one’s hands. In this paper, we discuss the viability of using smart eyewear to measure and visualize a reader’s physiological signals as well as provide some background in EDA research.

BackgroundEccrine sweat gland (SG) restrictedly exists in mouse foot pads indicating that mouse plantar dermis (PD) contains the SG lineage-restricted niches. However, it is still unclear how niches can affect stem cell fates.MethodsIn this study, we tried to find the key cues by which stem cells sense and interact with the SG lineage-specific niches. Briefly, we used transcriptomics RNA sequencing analysis to screen differentially expressed genes between SG cells and epidermal stem cells (ES), and then we used proteomic analysis to screen differentially expressed proteins between PD and dorsal dermis (DD).ResultsWe found that Notch1 is not only closely related to embryonic SG morphogenesis based on Gene Ontology enrichment analysis but also differentially down-regulated during SG formation in the levels of genes and proteins. Furthermore, immunochemistry and immunofluorescence staining verified that Notch1 was continuously down-regulated along with the process of SG morphogenesis. Especially, Notch1 positive cells almost disappeared neither in the emerging SG buds or in the newly-formed glandular structures.ConclusionHence, we speculated that Notch1 possibly acts as the role of “gatekeeper” during embryonic SG development and is the promising key cue that regulates the interactions between stem cells and the SG lineage-specific niches. Our attempts highlighted the role of Notch1 during embryonic SG organogenesis.Trial registration Not applicable.

Summary Despite being frequently overlooked during the examination of histopathological sections, eccrine sweat glands can offer clues for diagnosing various skin conditions. They provide important functions and can lead to several diseases when inflamed or injured. This review article provides information regarding eccrine physiology as well as well-established and novel entities that occur in association with eccrine gland pathology.

Syringomas are common benign appendageal tumors arising from eccrine sweat glands. They are commonly encountered in women, appearing as yellowish to skin-colored papules, 1–5 mm in diameter. They are typically distributed around the lower eyelids and malar areas; however, vulvar syringoma occurs rarely. Vulvar syringoma needs to be differentiated from papular eruptions occurring on the vulva. Histopathological examination may be needed to distinguish them from other disorders as clinical examination alone may fail to do so. Herein, we report two cases of vulvar syringomas.

We previously showed three-dimensional (3D) reconstructed eccrine sweat glands have similar structures as native eccrine sweat glands, but whether the 3D reconstructed sweat glands appropriately secrete fluid is still unknown. In this study, Matrigel-embedded human eccrine sweat gland cells or Matrigel alone were implanted into the groin subcutis of the nude mice. Ten weeks post-implantation, images of the subcutaneously formed plugs, as well as footpads of rats, pre- and post-pilocarpine/normal saline (NS) injection were acquired using a fat-suppressed proton density-weighted magnetic resonance imaging (MRI) sequence at 7.0 T, and the regions of interest (ROIs) in plugs and rat footpads were analysed and graphed. A significant increase in the ROI mean proton intensity occurred in both 3D reconstructed and native eccrine sweat glands after pilocarpine injection. The mean proton intensity had no noticeable changes in ROIs of Matrigel plugs between pre- and post-pilocarpine injection, and in ROIs of rat footpads between pre- and post-NS injection. In conclusion, the 3D reconstructed sweat glands possess fluid secretion, which is detectable by fat-suppressed proton density-weighted MRI.

Circadian dysfunction or dysregulation is associated with many chronic morbidities. Current state-of-art technologies do not provide an accurate estimation of the extent of disease affliction. Recent advances call for using wearables for improving management and diagnosis of circadian related disorders. Sweat contains an abundance of relevant biomarkers like cortisol, DHEA, and so forth, which could be leveraged toward tracking the user's chronobiology. In this article, we provide a review of the key developments in the field of wearable sensors for circadian technologies. We highlight the value of using sweat along with portable electronics toward developing state-of-the-art platforms for efficient diagnosis and management of chronic conditions. Finally, we discuss challenges and opportunities for using wearable sweat sensors for circadian diagnosis and disease management.

The skin is an extraordinary structure. It has a surface area of 2 m2 and accounts for 16–20% of the total body weight. The accessory structures include hairs, nails, sebaceous, sweat glands, sensory receptors, etc. The skin surface is a barrier between living processes and the potentially injurious outside world. The hair follicle openings can also be seen at the skin surface and the diameter of these orifices and the numbers per cm vary greatly between anatomical regions. The junctional zone has considerable functional importance and is vital to understanding the pathophysiology of bullous disorders and many other skin diseases. Hair follicles are arranged all over the skin surface apart from the palms and soles, the genital mucosa, and the vermilion of the lips. The eccrine sweat glands are an extremely important part of the body's homeothermic mechanism in that the sweat secretion evaporates from the skin surface to produce a cooling effect.

Eccrine sweat glands (ESGs) play an important role in temperature regulation by secreting sweat. Insufficiency or dysfunction of ESGs in a hot environment or during exercise can lead to hyperthermia, heat exhaustion, heatstroke, and even death, but the ability of ESGs to repair and regenerate themselves is very weak and limited. Repairing the damaged ESGs and regenerating the lost or dysfunctional ESGs poses a challenge for dermatologists and bum surgeons. To promote and accelerate research on the repair and regeneration of ESGs, we summarized the development, structure and function of ESGs, and current strategies to repair and regenerate ESGs based on stem cells, scaffolds, and possible signaling pathways involved.

Rationale: Eccrine spiradenoma (ES) is a rare benign skin adnexal tumor originating from eccrine sweat glands. The features of ES on ultrasonography (US) have received little attention. Therefore, we report the sonographic findings in a case of an ES that originated from the abdominal wall and discuss the previously reported cases. Patient concerns: A 53-year-old woman was admitted to our hospital with a complaint of a painful nodule on the right side of her abdominal wall of 1-year duration. Diagnoses: The mass on the right side of abdominal wall was diagnosed as ES by histopathological examination. Interventions: The patient subsequently underwent total excision of the mass. Outcomes: The patient recovered well and had no complications during the 1-year follow-up. Lessons: As eccrine spiradenoma (ES) is rare and most of the tumors are excised without prior imaging studies. Little is known regarding the features of ES on ultrasonography (US). Familiarizing with the clinical and US features of this rare tumor may increase awareness of the disease among sonographers and clinicians.

Spiradenocarcinoma, or malignant eccrine spiradenoma (MES), is a rare sweat gland tumor originating from eccrine sweat glands. To the best of our knowledge, only two cases of MES of the external auditory canal have been reported to date. Here, we report a third case of MES located in the external auditory canal.

SweatSenser Dx is a wearable biosensor system designed for continuous monitoring of the presence of biomarkers of interest in passive eccrine sweat. This device is designed to be worn on a user's wrist and leverages the capability of sensing ultra-low volume sweat samples using a flexible biosensor. This demonstration aims to show capability of sensing glucose and cortisol in human sweat, inthe absence of stimulation, using a Bluetooth exchange from the device to an app-server architecture for presentation of the concentration values.

Syringoma is a benign adnexal tumor of the skin originating from the eccrine sweat duct. There is a wide variety of treatments, and most of the patients receive multiple unsuccessful therapies. The goal of this report intends to describe a novel technique applicable to syringoma with botulinum toxin A. A 61-year-old female patient with localized syringomas in the periocular and upper lip region, with a long-lasting history, treated with botulinum toxin A 46 IU as monotherapy intradermally distributed and a follow-up for 8 months. Our patient displayed a significant improvement of the syringomas. Botulinum toxin A is an efficient and safe technique to treat syringomas.

Human eccrine sweat contains numerous biomarkers which can provide information on health,performance, and aging. Non-invasive collection and measurement of biomarkers has becomeespecially important in recent times given viral outbreaks like SARS-CoV-2. In the current studywe describe a method of sweat collection from palmar surfaces in participants via surface captureusing glass beads and the resulting analysis of biomarkers from very low volumes of sweat usingliquid chromatography mass spectrometry with selected ion monitoring. Study participantsunderwent a cognitive and physical stress task with easy and hard conditions with sweat beingcollected after each task. Resulting analysis found a signal for 22 steroid biomarkers and wereport detailed information on selected biomarkers, given their applicability to timely real-worldexemplars, including cortisol, dehydroepiandrosterone, allopregnanolone, estrone, aldosterone,and 20a/b-dihydrocortisone.

Neuropeptide Y (NPY) biomarker levels have a close association with the diagnosis of Major Depression Disorder (MDD) and anxiety disorders. Quantifying NPY in correlation to self-reported symptoms will be an important measure to ensure a relatively uniform diagnosis and help with disease prognosis of these disorders. The work presented is a novel, passive eccrine sweat based, electrochemical detection platform for quantification of NPY biomarker levels. The paper offers a comparison between non-porous and porous sensor platforms using various electrochemical detection techniques. This work uses a novel strategy towards designing an optimal nanobioelectronic interface to measure NPY. The portability aspect of this detection platform is discussed by the demonstration a novel, portable EmStat Pico based electronic platform. The detection limit of the sensor is 10 pg mL−1 and its range is 20–500 pg mL−1. The NPY detection platform is envisioned to be a wearable point-of need monitoring system for management of chronic anxiety disorders and MDD.

This paper contains details of work carried out to identify the most effective processing conditions for the optimized 1,2-indandione/zn formulation developed for use under UK conditions. Using direct measurements of fluorescence taken from test spots of amino acids and eccrine sweat during oven processing, complemented with experiments on real fingermarks, it was established that processing temperatures above 120°C in the oven were detrimental to the fluorescence of the developed mark. Alternative methods of development to oven processing were found to be effective, but less controllable. High levels of humidification were also found to be detrimental to the fluorescence of 1,2-indandione developed marks, and oven processing at 100°C and 0% relative humidity is therefore recommended for further studies. It has also been shown that 1,2-indandione can develop fingermarks at temperatures as low as 20°C, making it a candidate for use at crime scenes.

Hyperhidrosis is a condition where the amount of sweat released to skin surface increases due to the over-active eccrine sweat glands. Hyperhidrosis causes considerable psychosocial distress in affected people. It affects the quality of life and leads to social anxiety disorders.No study has been conducted in our country to investigate the epidemiological, clinical, and laboratory data of patients with hyperhidrosis. In this study, we aimed to retrospectively investigate the clinical and demographic characteristics, causes of sweating and laboratory findings in patients treated for hyperhidrosis at our outpatient clinic and to compare these data with the literature data.A retrospective review was conducted on medical records of patients diagnosed with and treated for hyperhidrosis at outpatient clinic between 2014 and 2017. Adults aged over 18 years were included in study. Age and gender of patients, type and localization of sweating, duration of disease, age of onset of sweating, presence of stress, fever, joint pain and comorbidity, family history, medication use, and examination results were recorded.Records of a total of 70 patients consisting of 30 men and 40 women with hyperhidrosis were examined. Overall mean age was 37.1 years. Mean age was 41 years in women and 32 years in men. Most frequent forms were palmoplantar and axillary hyperhidrosis for primary hyperhidrosis (primary HH), and head-neck and generalized hyperhidrosis for secondary hyperhidrosis (secondary HH). Most common comorbidities were diabetes mellitus, thyroid disease, non-specific joint and bone pain, cardiovascular disease, and neuropsychiatric disease. Cases with secondary HH had a history of drug use (antithyroid drugs, nonsteroidal anti-inflammatory drugs, antidiabetic agents, antidepressants, and antihypertensives).This is the first study that investigated the characteristics of patients with primary and secondary HH in our country. These characteristics can help determine the cause and apply treatment for hyperhidrosis by an appropriate examination and approach.

A 3-year-old Japanese boy presented with a 3-month history of itchy erythematous papules on his trunk and forearms, the histologic findings of which were characterized by predominantly neutrophilic inflammation within and around the eccrine sweat ducts and obliteration and disruption of the superficial eccrine sweat ducts. Although the skin disorder had some clinical and histopathologic similarity to miliaria and neutrophilic eccrine hidradenitis, it was ultimately conformed to be neither disorder. Based on this and a case report in the Japanese literature of a 1-year-old boy with erythematous eruptions whose clinical and histopathologic findings were similar to those in our case, we propose the skin disorder in our case, referred to as "neutrophilic superficial eccrine ductitis," as a unique entity.

Background: Previous studies demonstrate that eccrine sweat glands are innervated by both cholinergic and adrenergic nerves. However, it is still unknown whether the secretory coils and ducts of eccrine sweat glands are equally innervated by the sympathetic nerve fibers. To well understand the mechanisms on sweat secretion and reabsorption, the differential innervation of secretory coils and ducts in human eccrine sweat glands was investigated in the study. Methods: From June 2016 to June 2017, six human skins were fixed, paraffin-embedded, and cut into 5 μm-thick sections, followed by costaining for nerve fiber markers protein gene product 9.5 (PGP 9.5), tyrosine hydroxylase (TH) and vasoactive intestinal peptide (VIP), and eccrine sweat gland markers K7, S100P, and K14 by combining standard immunofluorescence with tyramide signal amplification (IF-TSA). Stained sections were observed under the microscope, photographed, and analyzed. Results: The fluorescent signals of PGP 9.5, TH, and VIP were easily visualized, by IF-TSA, as circular patterns surrounding eccrine sweat glands, but only PGP 9.5 could be observed by standard IF. The IF-TSA method is more sensitivity than standard IF in detecting antigens expressed at low levels. PGP 9.5, TH, and VIP appeared primarily surrounding the secretory coils and sparsely surrounding the sweat ducts. Conclusion: Sweat secretion is mainly controlled by autonomic nerves whereas sweat reabsorption is less affected by nerve activity.

This work demonstrates an electrochemical label-free cortisol aptasensor (Cortisol Apta-Watch (CATCH) for detection of cortisol from passively perspired eccrine sweat. The platform is designed to track cortisol levels in sweat to understand the implications of stress in different physiological processes of the body. The sensor platform is characterized with zeta potential, FTIR, and electrochemical measurements to understand the aptamer binding chemistry and cortisol binding sensitivity. Following this, the platform's sensitivity to cortisol analyte concentration in human sweat is evaluated using impedimetric and chronoamperometric methods. The results highlight the platform's sensitivity to cortisol with a detection limit of ~1 ng/mL in human sweat and a dynamic range of 1–256 ng/mL. The performance metrics highlight the ability of the sensor to sensitively detect cortisol in human sweat with high significance (p

Syringomas are benign adnexal neoplasm of eccrine sweat duct usually affecting adult women. They present as firm, skin coloured to yellowish papules in a symmetrical distribution over periorbital region. Eruptive syringomas are infrequent and usually appear at uncommon sites. Herein, we report a case of a 21-year old girl with eruptive syringomas with an extensive involvement.

Rationale: Eccrine poroma, a benign cutaneous neoplasm originating from the intraepidermal portion of the eccrine sweat duct, is relatively common in clinical practice. Nevertheless, the 1 presenting as spindle-shaped plaque is extremely rare and easily misdiagnosed as seborrheic keratosis or other dermatoses. Thus, the current study demonstrates a case of eccrine poroma with unique clinical manifestation. Patients concerns: A 47-year-old man presented with a spindle-shaped plaque on his left sole for 6 years. Diagnoses: Based on the clinical and histopathological manifestations, diagnosis of eccrine poroma was established. Interventions: Surgical excision under local anesthesia was performed. Outcomes: No recurrence or malignant transformation occurred within 6-month follow-up. Lessons: Eccrine poroma typically presents as a dome-shaped nodule on palm or sole. But this case reminded us the lesion presenting as a spindle-shaped plaque on sole can not rule out the possibility of eccrine poroma.

During periods of activity, sweat glands produce pressures associated with osmotic effects to drive liquid to the surface of the skin. The magnitudes of these pressures may provide insights into physiological health, the intensity of physical exertion, psychological stress factors and/other information of interest, yet they are currently unknown due to absence of means for non-invasive measurement. This paper introduces a thin, soft wearable microfluidic system that mounts onto the surface of the skin to enable precise and routine measurements of secretory fluidic pressures generated at the surface of the skin by eccrine sweat glands (surface SPSG, or s-SPSG) at nearly any location on the body. These platforms incorporate an arrayed collection of unit cells each of which includes an opening to the skin, an inlet through which sweat can flow, a capillary bursting valve (CBV) with a unique bursting pressure (BP), a corresponding microreservoir to receive sweat and an outlet to the surrounding ambient to allow release of backpressure. The BPs systematically span the physiologically relevant range. The set of unit cells is designed such that the BP difference between any two unit cells is greater than the combined uncertainty. Human studies demonstrate measurements of s-SPSG under different conditions, from various regions of the body. Average values in healthy young adults lie between 2.4 and 2.9 kPa. Sweat associated with vigorous exercise have s-SPSGs that are somewhat higher than those associated with sedentary activity. For all conditions, the forearm and lower back tend to yield the highest and lowest s-SPSGs, respectively.

Eccrine syringofibroadenoma is a very rare benign tumour of acrosyringium of eccrine sweat duct. Based on the evidences of known etiological factors, two forms have been proposed; reactive and nonreactive. Reactive forms are rarer, and on even rarer occasions, trauma complicated by secondary nonspecific infections may lead to the development of reactive eccrine syringofibroadenoma, as in our case. Here, we are documenting a case of reactive solitary eccrine syringofibroadenoma in a 65-year-old male presenting with coalescing, firm, pinkish, verrucous nodules and painful deep ulceration on the right sole preceded by trauma and secondary infection. Histopathologic revelation of distinctive microscopic findings confirmed the diagnosis in our case.

The time necessary for the initial appearance of ingested water as sweat during exercise in the heat remains unknown. Based on the current literature, we estimated fluid transition through the body, from ingestion to appearance as sweat, to have a minimum time duration of approximately three minutes. The purpose of this study was to test this prediction and identify the time necessary for the initial enrichment of deuterium oxide (D2O) in sweat following ingestion during exercise in the heat. Eight participants performed moderate intensity (40% of maximal oxygen uptake) treadmill exercise in an environmental chamber (40°C, 40% rH) to induce active sweating. After fifteen minutes, while continuing to walk, participants consumed D2O (0.15mlkg-1) in a final volume of 50ml water. Scapular sweat samples were collected one minute prior to and ten minutes post-ingestion. Samples were analyzed for sweat D2O concentration using isotope ratio mass spectrometry and compared to baseline. Mean±SD ∆ sweat D2O concentration at minutes one and two post-ingestion were not significantly higher than baseline (0min). Minutes three (9±3ppm) through ten (23±11ppm) post-ingestion had ∆ sweat D2O concentrations significantly (P

Key Clinical Message Eccrine spiradenoma is a benign and rare adnexal tumor originating from cutaneous eccrine sweat glands. It usually presents as a solitary lesion. It can have different presentations, including a blaschkoid arrangement which is rare. Malignant transformation is possible and usually occurs after a long period of latency in multifocal types.

The helical sweat ducts (HSD) in human skin were anchored as the dominant structure of skin governing its electromagnetic (EM) behavior in the sub-terahertz band (sub-THz). We present an improved EM human skin model in the Y-band, which is rather complicated as it takes the fine structure of the upper skin layer into account, together with its dielectric properties. We present for the first time, the transmitting mode of human sweat ducts, as well as its receiving mode. In addition, by considering the eccrine sweat ducts as interactive elements with non-random distribution, we demonstrate for the first time an antenna-array-like behavior of human sweat ducts.

This is a benign tumor of the eccrine sweat glands and ducts that tends to occur in young women. The cause remains unknown, but there are reported series of familial cases [1].

In this chapter, the separate and combined effects of changes in ambient temperature, humidity, and metabolic heat production will be explored. First principles are used to demonstrate how those states exert a physiological impact. Our evolutionary heritage equipped us with a capacity for continued heat production, which, during elevated thermal stress, could be distributed to near-naked skin through cutaneous vascular networks, and dissipated by evaporating fluid secreted from eccrine sweat glands. Recent evidence concerning the control of those thermoeffectors will be presented, including their morphological dependency. Those processes enable the physiological compensation of, and adaptation to, acute and chronic changes in whole-body heat storage, using neurally mediated homeostatic mechanisms. However, those mechanisms are embedded within other complex and integrated regulatory networks. Consequently, while both frank hypothermia and hyperthermia can be life-threatening, for clothed workers, cardiovascular insufficiency is a more likely cause of work-related thermal intolerance.

Despite the many ergonomic advantages of eccrine perspiration (sweat) compared to other possible biofluids (particularly in “wearable” devices), sweat remains an underrepresented source of biomarker analytes compared to the established biofluids blood, urine, and saliva. Upon closer comparison to other non-invasive biofluids, the advantages may even extend beyond ergonomics: sweat might provide superior analyte information. A number of challenges, however, have historically kept sweat from its place in the pantheon of clinical samples. These challenges include very low sample volumes (nL to µL), unknown concentration due to evaporation, filtration and dilution of large analytes, mixing of old and new sweat, and the potential for contamination from the skin surface. More recently, rapid progress in “wearable” sweat sampling and sensing devices has resolved several of the historical challenges. However, this recent progress has also been limited to high concentration analytes (µM to mM) sampled at high sweat rates (>1 nL/min/gland, e.g. athletics). Progress will be much more challenging as sweat biosensing moves towards use with sedentary users (low sweat rates or not sweating at all) and/or towards low concentration analytes (pM to nM). Addressing these unresolved challenges will require significant advances in sweat stimulation, sample collection efficiency, compact sensors, and likely more. Fortunately, none of the remaining challenges appear to be fundamentally blocking, and scientific and engineering innovations have the opportunity to enable broader application of sweat biosensing technology.

Resumen: Introducción: La Hidradenitis palmoplantar ecrina idiopática (HPPI) es una dermatosis neutrofílica infrecuente, que cursa con nódulos eritematosos dolorosos de comienzo brusco en regiones plantares o palmoplantares, en niños que no tienen otra enfermedad subyacente. Objetivo: Presentar un caso que ilustra las principales características clínicas e histológicas de la HPPI. Caso Clínico: Niña de 11 años evaluada por nódulos eritematovioláceos dolorosos en planta de pie derecho de 48 horas de evo lución y fiebre de hasta 38,2 °C, sin antecedentes de interés salvo hiperhidrosis y práctica intensa de ejercicio en los días previos. Ante la sospecha clínica de HPPI se realizó biopsia cutánea, que mostró infiltrado inflamatorio neutrofílico alrededor de glándulas sudoríparas ecrinas y abscesos de neutrófilos, confirmando el diagnóstico. Se indicaron antiinflamatorios no esteroidales orales y reposo, con resolución de las lesiones en 7 días. Conclusiones: Este caso demuestra los aspectos más importantes de la HPPI. Esta entidad en muchos casos es infradiagnosticada, dado que puede confundirse con otras patologías que también cursan con nódulos acrales dolorosos, pero tienen distintas implicacio nes patogénicas y terapéuticas. Identificar apropiadamente la HPPI permite evitar la alarma innece saria, tanto en pacientes y sus padres, como en los propios dermatólogos y pediatras.

Wearable electronic monitors hold great promise in helping people to reach their health goals. These increasingly sophisticated devices help the wearers improve their wellness by constantly monitoring their activities and bodily responses. While consumer wearables that are non–sweat based have been useful for monitoring body vital parameters. However, solutions leveraging human sweat are still in the early stages of development. Wearable devices hold the potential to transform some industries most importantly the health care industry. Wearable sweat based diagnostic biosensors for the detection and monitoring of analytes in transdermal sweat present an intriguing pathway toward improving user health outcomes in an inexpensive and noninvasive manner. Transdermal biosensors have become a more viable option in recent years, due in large part to the miniaturization of conventional sensing mechanisms. Current minimally invasive strategies demonstrate encouraging results in the monitoring of select biomarkers in peripheral blood and interstitial fluid, but these devices are still minimally invasive as they puncture the skin. Current transdermal sweat biosensors require relatively large volumes in a localized region and count on chemically-induced sweating to attain sufficient sample volume. Thus, there exists a challenge in designing wearable sweat-based sensors that can report and quantify biomarkers of interest from low volumes of human sweat in a completely non-invasive yet still cost-effective manner. In this talk I will present some non-invasive sweat sensing technologies that detect and quantify biomarkers in human sweat.

Introduction Sweat based wearable sensors have shown a lot of promise in the recent years due to the ability of tracking the biomarkers in real-time. Among the various biomarkers present in sweat, cytokine concentrations have been shown in comparable range to the blood cytokines. Detection of sweat cytokines can help in monitoring of inflammation in real-time. In this work, we demonstrate a duplex cytokine sweat based sensor for real-time monitoring. The developed sensor can detect interleukin-6 (IL-6) and interleukin-10 (IL-10) in real-time that can aid in prognosis or recovery of inflammation. Materials and Methods The sweat based sensor was developed with semiconducting electrode on porous polymeric substrate on a porous polymer substrate. Affinity capture probes were immobilized on the sensor surface via a thiol-cross linking chemistry. ATR-IR was used to validate immobilization of the capture probes. Electrochemical impedance measurements technique was used to detect the interaction between the specific antibody and target analyte. The impedance response based on the binding interaction was used to quantify the sensor metrics. Results In this work, a sweat sensor platform for the duplex detection of IL-6 and IL-10 has been demonstrated. The conjugation of the antibodies to the sensor surface was confirmed using ATR-IR spectroscopy. Impedance response was used to characterize the sensor performance metrics. Calibration dose response curve was developed with decreasing impedance response for increasing concentrations of target analyte. A limit of detection of 2 pg/mL was obtained with a dynamic range from 2 pg/mL- 200 pg/mL for IL-6. IL-10 demonstrated a limit of detection of 1.5pg/mL with a dynamic range from 1.5- 150pg/mL. The developed sensor demonstrated minimal or no cross-reactivity to non-specific molecules. Conclusion A novel sweat-based biosensor for duplex detection of cytokine markers has been demonstrated. The developed biosensor can detect pro and anti-inflammatory cytokines that can aid in the prognosis or recovery of inflammation.