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The presence of mechanoreceptors in glabrous skin allows humans to discriminate textures by touch. The amount and distribution of these receptors defines our tactile sensitivity and can be affected by diseases such as diabetes, HIV-related pathologies, and hereditary neuropathies. The quantification of mechanoreceptors as clinical markers by biopsy is an invasive method of diagnosis. We report the localization and quantification of Meissner corpuscles in glabrous skin using in vivo, non-invasive optical microscopy techniques. Our approach is supported by the discovery of epidermal protrusions which are co-localized with Meissner corpuscles. Index fingers, small fingers, and tenar palm regions of ten participants were imaged by optical coherence tomography (OCT) and laser scan microscopy (LSM) to determine the thickness of the stratum corneum and epidermis and to count the Meissner corpuscles. We discovered that regions containing Meissner corpuscles could be easily identified by LSM with an enhanced optical reflectance above the corpuscles, caused by a protrusion of the strongly reflecting epidermis into the stratum corneum with its weak reflectance. We suggest that this local morphology above Meissner corpuscles has a function in tactile perception.

The proximate mechanisms underlying foraging behavior in sea otters (Enhydra lutris) are relatively unknown despite decades of research focused on the biology and ecology of this top predator. Sea otters prey on infaunal or visually cryptic benthic invertebrates, but maintain a high rate of capture to consume a quarter of their body mass each day. Consequently, sea otter sensory systems have been shaped by selective pressures for accurate and efficient detection of prey location and assessment of prey quality. This dissertation describes a series of behavioral experiments with trained sea otters and anatomical studies from post-mortem sea otters to assess the visual and tactile capabilities of this species in the context of underwater foraging behavior. Chapter 1 focuses on the visual sense and potential adaptations for foraging in marine environments and low light. This material comprises quantitative and qualitative descriptions of pupil mobility, retinal photoreceptor distribution, and tapetal morphology to assess low-light sensitivity relative to previously demonstrated amphibious acuity. We find that sea otter pupils adjust in size to variable light levels and sea otter retinas retain features that enhance sensitivity in low light. However, pupillary dynamic size range and visual acuity in low light are limited relative to other marine carnivores, likely due to a smaller absolute eye size, non-specialized circular pupil shape, and a reliance on a narrow range of pupil sizes to adequately deform the lens to retain visual acuity under water. Given that sea otters forage successfully across a wide range of light levels and for buried prey, the conclusions from Chapter 1 motivated subsequent investigations of whether sea otter touch abilities are sensitive enough to compensate for the loss of visual focus in low light. The results presented in Chapters 2 are drawn from a comprehensive series of four experiments with a trained sea otter to directly measure in-air and underwater tactile sensitivity for paws and facial vibrissae. These studies provide a behavioral means to evaluate predictions based on previous research of sea otter brain and vibrissal morphology. We find that sea otter paw and vibrissal sensitivities are comparable to other tactile specialists, but paw-based touch is especially acute and comparable to human hands. Additionally, sea otter decision times were reliably less than 250 ms for paw and 500 ms for vibrissae, which suggests that sea otters can make fast and accurate decisions based on information received through touch. Chapter 3 builds on the behavioral results from Chapter 2 to investigate the density and distribution of sensory receptors and associated circulatory structures in sea otter glabrous (i.e., hairless) skin—paw pads, flipper digit pads, lips, and the rhinarium—and to link the degree of neural investment to differential sensitivity and use of these regions in observed sea otter behavior. We confirm the presence of two mammalian mechanoreceptor types—Merkel cells and Pacinian corpuscles—and find that their densities, as well as corresponding neural and blood supply, were highest in the paw digit tips and substantially lower in other glabrous skin. This pattern of increased neural investment is consistent with the areas of the paw primarily used for texture discrimination in Chapter 2, which suggests that the distal paw serves as a tactile fovea in sea otters. As a body of work, this dissertation combines structural and functional approaches to provide a more comprehensive assessment of the visual and tactile systems in sea otters. The findings from these studies not only contribute foundational knowledge about the sensory biology of sea otters, but also offer a mechanistic framework to interpret behavioral patterns and energy expenditure observed in wild sea otters across variable environmental conditions.

Case report A 76-year-old Caucasian woman with a history of previous BCCs excised from the head and legs was referred from the dermatology team with a biopsy proven superficial BCC to the left palm. The patient had presented to the dermatology team with the same lesion 7 years prior to the definitive diagnosis. The lesion was described as 27 × 15 mm scaly, poorly-defined, plaque-like lesion to the central palm. There was no ulceration or visible telangiectasia. At the time, an initial diagnosis of psoriasis was given and she received several courses of topical treatments to no avail. Eventually, a biopsy was taken which revealed a multifocal superficial BCC. After unsuccessful attempts at treating with topical Imiquimod, the lesion was surgically excised and resurfaced with a full thickness skin graft. Discussion The current understanding that BCCs derive from cells of the hair follicle cannot explain their appearance on the palm. Alternative hypotheses have been proposed as to their actual origin which would account for this rare occurrence. Ultimately, histology can determine the nature of the lesion. We urge clinicians encountering atypical, non-healing lesions to glabrous skin to keep in mind a diagnosis of skin cancer as a delayed diagnosis can lead to increased morbidity.

The purposes of this study were to assess 1) whether the sinusoidal thermal load test can evaluate dynamic responsiveness of skin vessels in the extremities of limbs, and 2) whether the vascular responses to sinusoidal thermal load differ in glabrous and nonglabrous human skin. Ten healthy subjects immersed their hand into a water bath at 34℃ for 10 min, and for the next 60 min or 80 min, the water temperature was sinusoidally changed at an ambient temperature of 26℃ and relative humidity of 60%. The variation of sinusoidal thermal load ranged from 31.5℃ to 36.5℃ over three 20-min periods or from 29℃ to 39℃ over two 40-min periods. The phase and amplitude responses of cutaneous vascular conductance (CVC) in the dorsal hand (i.e. nonglabrous site) and palm (i.e. glabrous site) to sinusoidal changes in water temperature were measured. Skin blood flow (SkBF) was monitored by laser-Doppler flowmetry. CVC was evaluated from the ratio of SkBF to mean arterial pressure. During baseline measurement at 34℃, the CVC in the dorsal hand was lower than that in the palm (P, 本研究の目的は、1）正弦波状温熱負荷により四肢末端部の皮膚血管運動の動的反応性が評価できるか否か、そ して2）正弦波状温熱負荷に対する皮膚血管反応は無毛部と有毛部で異なるかどうかを検討することであった。環 境温26℃、相対湿度60％の条件下で、10名の健康な被験者が34℃に設定した恒温水槽に手を10分間浸漬し、続い て水温を60分間あるいは80分間正弦波状に変化させた。正弦波状温熱負荷は、31.5℃と36.5℃の間で20分の周期で3 回、あるいは29℃と39℃の間で40分の周期で2回変動させた。水温の正弦波状変化に対する手背部（すなわち有毛 部）と手掌部（すなわち無毛部）の皮膚血管コンダクタンス（CVC）の位相と振幅の応答を測定した。皮膚血流 量（SkBF）はレーザードップラー法によりモニターされ、CVCはSkBFと平均血圧の比率から評価された。34℃ でのベースライン測定中、手背部CVCは手掌部CVCよりも低かった（P

Introduction Dermatophytoses are the most common superficial fungal infections in paediatric population. Its pathogen pattern has changed over years. Aim To analyse the spectrum of dermatophytoses in children living in Southwestern Poland, in the years 2011–2016. Material and methods A total of 1705 patients were diagnosed with fungal skin infection in the Mycological Laboratory, Dermatology Department of the Wroclaw Medical University. Of them, 163 were under 18 years of age. Results In 105 cases, dermatophytoses were detected. The collected specimens were examined using direct microscopy examination, staining, culture on specific media and PCR technique. The most common dermatophytes were Trichophyton rubrum and Trichophyton tonsurans (31.4% each), followed in the descending order by Trichophyton mentagrophytes (21.9%), Microsporum canis (13.3%) and Epidermophyton floccosum (1.9%). The most commonly affected body sites were glabrous skin of the trunk and extremities (41.7%), followed by face (22.2%), scalp (15.7%) and toe nails (14.8%). Conclusions This study revealed the most common types of dermatophytoses and their pathogens in children in Southwestern Poland. In comparison to earlier data obtained from this region, new epidemiological trends have been revealed. We observed the shift towards anthropophilic dermatophyte infections and an increasing number of onychomycosis in children. Because of climatic variations, migration, and changing lifestyle practices, further studies on dermatophytoses are necessary to improve our knowledge on the epidemiology of fungal infections.

Summary Objective Increased foot‐ground contact loading engenders adaptive glabrous skin thickening and can decrease mechanoreceptor acuity and alter plantar cutaneous sensation. There has not been any research on whether overweight and obesity are similarly associated with normal plantar cutaneous sensation scores in children. This study investigated the associations between normal plantar cutaneous sensation scores and weight status (i.e., healthy weight, overweight, and obesity) in a sample of youth. Methods Plantar sensation was tested among 122 participants aged 8 to 16 years (10.3 ± 1.8 years; 140.0 ± 11.2 cm; 44.2 ± 16.0 kg) across the forefoot, midfoot, and rearfoot using Semmes‐Weinstein pressure aesthesiometry (0.07 g and 0.4 g monofilaments). Weight status was determined using the Centers for Disease Control and Prevention growth charts. Age‐ and sex‐adjusted models were used to explore the relationships between normal plantar sensation scores and weight status. Significant two‐tailed tests were set at p < .05. Results Only obesity was inversely associated with normal plantar sensation scores on the left (β = −.241; p = .009) and right (β = −.222; p = .018) forefeet, left (β = −.322; p = .001) and right (β = −.253; p = .007) midfeet, and left (β = −.286; p = .002) and right (β = −.228; p = .014) wholefeet (relative to healthy weight) when using the 0.07 g monofilament. There was no association between obesity and plantar sensation when using the 0.4 g monofilament. Conclusions Obesity is associated with diminished light touch plantar sensation. Considering previously reported higher mechanical loading and the fact that Merkel cells and the Aβfibers that innervate them are superficial to the hypodermis, adaptive glabrous skin thickening (rather than fat pad thickness) may underlie this association. Contrary to previous suggestions, overweight is not associated with decreased plantar cutaneous sensation.

Illusions of the perceived distance between two touches on the skin have been studied since the classic work of Weber in the 19th century. For example, anisotropies of perceived tactile distance have been consistently found on several body parts, including the hand dorsum, the forearm, and the face. In each case, tactile distances that are oriented across body width are perceived as being larger than those oriented along body length. Several studies have investigated tactile distance anisotropy on the glabrous skin of the palm of the hand, but they have reached inconsistent conclusions-with some studies finding no anisotropy, and others finding an anisotropy analogous to that found on the dorsum. Given these inconsistencies, the aim of this study was to conduct a systematic meta-analysis of the existing data regarding anisotropy on the palm. A total of ten experiments were identified, which overall provided strong evidence for an anisotropy on the palm (Hedges's g = 0.521), with distances aligned with hand width being perceived as approximately 10% bigger than distances aligned with hand length. While this anisotropy is analogous to that found on the hand dorsum, it is substantially smaller in magnitude, and the two biases appear to be uncorrelated. The present results show that, despite inconsistent results across studies, the existing data do indicate an anisotropy of tactile distance on the palm of the hand.

This article presents an analysis of publications on strains resistant to antifungal drugs and describes a clinical case of a 57-year-old patient suffering from distributed glabrous skin mycosis with foot nail lesions resistant to antifungal therapy. The clinical picture, diagnosis and treatment of the fungal disease is described. Against the background of antifungal treatment, the clinical and mycological cure of the trunk skin and foot nail mycosis was achieved.

Objective: Due to the similarities of glabrous skin, the plantar region is an excellent donor area for covering complex palmar–plantar wounds. However, taking grafts from the plantar area often results in significant morbidity at the donor site or non-integration of the graft due to the greater thickness of the plantar corneal layer. Method: This is a prospective case series including patients with burns or wounds who have been treated with a dermal graft using the bilaminar ‘trapdoor’ technique. This procedure is used to remove a thin graft from the deep plantar dermis after the partial elevation of the first layer including the entire epidermis and superficial part of the dermis. Results: At the donor area in the four patients in this case series, we observed healing at around 10 days, and absence of hypertrophic scar in all patients. There was complete re-epithelialisation between two and three weeks from the periphery to the centre of the deep dermal graft, and from the glandular epithelium transferred with the graft. During the follow-up, patients presented aesthetic and functional features of glabrous and amelanotic skin, with similar resistance to those of the adjacent areas of the wound in the palmar–plantar region. Conclusion: This technique has some advantages, such as less surgical time, minimal morbidity in the plantar donor area, easy integration of the grafts, and maintenance of the functional and aesthetic properties of glabrous skin both in the plantar donor area and in the palmar–plantar recipient region. Declaration of interest: The authors have no conflicts of interest to declare.

Summary:. Percutaneous needle fasciotomy (PNF) is a favorable approach to Dupuytren’s contracture management, usually reserved for Tubiana stage 1–2, uncomplicated disease. It is growing in popularity globally. Epidermal inclusion cysts are benign, commonly encountered cavities usually found on acral skin, rarely glabrous skin, and often following trauma. We present a 43-year-old laborer with two incidentally found epidermal inclusion cysts in the open excision of painful, Tubiana 3 and 2 Dupuytren’s recurrence of his middle and ring fingers. He had undergone PNF to same 4 years prior. One cyst had ruptured. Both seemed to have migrated distally over time from the initial PNF site with progression of the Dupuytren’s disease. This may be the only case of multiple epidermal inclusion cysts post PNF for Dupuytren’s disease in the literature. The authors discuss factors contributing to epidermal inclusion cyst formation, and postulate whether needle choice may impact the risk of their development as a complication of PNF.

The ridged skin of the palms and soles has several unique features: (i) presence of dermatoglyphics created by alternating ridges and grooves forming a unique pattern, (ii) presence of the highest density of eccrine sweat glands and absence of pilosebaceous units, and (iii) differential expression of keratins compared to the glabrous skin. These features explain the preferential localization of palmoplantar keratoderma (PPK) and several of its characteristic clinical features. PPK develops as a compensatory hyperproliferation of the epidermis and excessive production of stratum corneum in response to altered cornification of the palmoplantar skin due to mutations in the genes encoding several of the proteins involved in it. PPK can manifest as diffuse, focal, striate, or punctate forms per se or as a feature of several dermatological or systemic diseases. There is a wide genetic and phenotypic heterogeneity in hereditary PPK, due to which reaching an accurate diagnosis only on the basis of clinical features may be sometimes challenging for the clinicians in the absence of molecular studies. Nevertheless, recognizing the clinical patterns of keratoderma, extent of involvement, degree of mutilation, and associated appendageal and systemic involvement may help in delineating different forms. Molecular studies, despite high cost, are imperative for accurate classification, recognizing clinical patterns in resource poor settings is important for appropriate diagnosis, genetic counseling, and management. This review intends to develop a practical approach for clinical diagnosis of different types of hereditary PPK with reasonable accuracy.

Itch arising from glabrous skin (palms and soles) has attracted limited attention within the field due to the lack of methodology. This is despite glabrous itch arising from many medical conditions such as plantar and palmar psoriasis, dyshidrosis, and cholestasis. Therefore, we developed a mouse glabrous skin behavioral assay to investigate the contribution of three previously identified pruriceptive neurons in glabrous skin itch. Our results show that MrgprA3+ and MrgprD+ neurons, although key mediators for hairy skin itch, do not play important roles in glabrous skin itch, demonstrating a mechanistic difference in itch sensation between hairy and glabrous skin. We found that MrgprC11+ neurons are the major mediators for glabrous skin itch. Activation of MrgprC11+ neurons induced glabrous skin itch, while ablation of MrgprC11+ neurons reduced both acute and chronic glabrous skin itch. Our study provides insights into the mechanisms of itch and opens up new avenues for future glabrous skin itch research.

Perception of distance between two touches varies with orientation on the hand, with distances aligned with hand width perceived as larger than those aligned with hand length. Similar anisotropies are found on other body parts (e.g., the face), suggesting they may reflect a general feature of tactile organization, but appear absent on other body parts (e.g., the belly). Here, we investigated tactile-distance anisotropy on the foot, a body part structurally and embryologically similar to the hand, but with very different patterns of functional usage in humans. In three experiments, we compared the perceived distance between pairs of touches aligned with the medio-lateral and proximal-distal foot axes. On the hairy skin of the foot dorsum, anisotropy was consistently found, with distances aligned with the medio-lateral foot axis perceived as larger than those in the proximo-distal axis. In contrast, on the glabrous skin of the sole, inconsistent results were found across experiments, with no overall evidence for anisotropy. This shows a pattern of anisotropy on the foot broadly similar to that on the hand, adding to the list of body parts showing tactile-distance anisotropy, and providing further evidence that such biases are a general aspect of tactile spatial organization across the body. Significance: The perception of tactile distance has been widely used to understand the spatial structure of touch. On the hand, anisotropy of tactile distance perception is well established, with distances oriented across hand width perceived larger than those oriented along hand length. We investigated tactile-distance anisotropy on the feet, a body part structurally, genetically, and developmentally homologous to the hands, but with strikingly different patterns of functional usage. We report highly similar patterns of anisotropy on the hairy skin of the hand dorsum and foot dorsum. This suggests that anisotropy arises from the general organization of touch across the body.

RATIONALE Degloving foot injuries are challenging to treat and associated with life-long sequelae for patients. An appropriate debridement of ischemic soft tissues with maximal preservation of glabrous skin is key during the reconstruction of these injuries. Indocyanine green (ICG) fluorescence angiography is an established technique for the intraoperative evaluation of tissue perfusion. PATIENT CONCERNS Two patients sustained complex foot injuries in traffic accidents, including multiple fracture dislocations and extensive degloving of the plantar skin. DIAGNOSIS Clinical inspection revealed significant degloving of the glabrous skin in both patients. INTERVENTIONS After fracture fixation, ICG fluorescence angiography-assisted debridement with immediate latissimus dorsi free flap reconstruction was performed. OUTCOMES In both cases, this technique allowed a precise debridement with maximal preservation of the glabrous skin. The healing of the remaining glabrous skin was uneventful and the 6-month follow-up was characterized by stable soft tissues and satisfying ambulation. LESSONS ICG fluorescence angiography is a safe, user-friendly, and quick procedure with minimal risks, expanding the armamentarium of the reconstructive surgeon. It is highly useful for the debridement of extensive plantar degloving injuries and may also help to minimize the number of procedures and the risk of infection.

Mammals use glabrous (hairless) skin of their hands and feet to navigate and manipulate their environment. Cortical maps of the body surface across species contain disproportionately large numbers of neurons dedicated to glabrous skin sensation, potentially reflecting a higher density of mechanoreceptors that innervate these skin regions. Here, we find that disproportionate representation of glabrous skin emerges over postnatal development at the first synapse between peripheral mechanoreceptors and their central targets in the brainstem. Mechanoreceptor synapses undergo developmental refinement that depends on proximity of their terminals to glabrous skin, such that those innervating glabrous skin make synaptic connections that expand their central representation. In mice that do not sense gentle touch, mechanoreceptors innervating glabrous skin still make more powerful synaptic connections in the brainstem. We propose that the skin region a mechanoreceptor innervates controls refinement of its central synapses over development to shape the representation of touch in the brain.

Mammals use the glabrous (hairless) skin of their hands and feet to navigate and manipulate their environment. Cortical maps of the body surface across species contain disproportionately large numbers of neurons dedicated to glabrous skin sensation, potentially reflecting a higher density of mechanoreceptors that innervate these skin regions. Here, we find that disproportionate representation of glabrous skin emerges over postnatal development at the first synapse between peripheral mechanoreceptors and their central targets in the brainstem. Mechanoreceptor synapses undergo developmental refinement that depends on proximity of their terminals to glabrous skin, such that those innervating glabrous skin make synaptic connections that expand their central representation. In mice that do not sense gentle touch, mechanoreceptors innervating glabrous skin still make more powerful synapses in the brainstem. We propose that the skin region a mechanoreceptor innervates controls refinement of its central synapses over development to shape the representation of touch in the brain.

Fingertip mechanoreceptors comprise sensory neuron endings together with specialized skin cells that form the end-organ. Exquisitely sensitive, vibration-sensing neurons are associated with Meissner's corpuscles in the skin. In the present study, we found that USH2A, a transmembrane protein with a very large extracellular domain, was found in terminal Schwann cells within Meissner's corpuscles. Pathogenic USH2A mutations cause Usher's syndrome, associated with hearing loss and visual impairment. We show that patients with biallelic pathogenic USH2A mutations also have clear and specific impairments in vibrotactile touch perception, as do mutant mice lacking USH2A. Forepaw rapidly adapting mechanoreceptors innervating Meissner's corpuscles, recorded from Ush2a -/- mice, showed large reductions in vibration sensitivity. However, the USH2A protein was not found in sensory neurons. Thus, loss of USH2A in corpuscular end-organs reduced mechanoreceptor sensitivity as well as vibration perception. Thus, a tether-like protein is required to facilitate detection of small-amplitude vibrations essential for the perception of fine-grained tactile surfaces.

International audience; C-tactile (CT) afferents were long-believed to be lacking in humans, but were subsequently shown to densely innervate the face and arm skin, and to a lesser extent the leg. Their firing frequency to stroking touch at different velocities has been correlated with ratings of tactile pleasantness. CT afferents were thought to be absent in human glabrous skin; however, tactile pleasantness can be perceived across the whole body, including glabrous hand skin. We used microneurography to investigate mechanoreceptive afferents in the glabrous skin of the human hand, during median and radial nerve recordings. We describe CTs found in the glabrous skin, with comparable characteristics to those in hairy arm skin, and detail recordings from three such afferents. CTs were infrequently encountered in the glabrous skin and we estimate that the ratio of recorded CTs relative to myelinated mechanoreceptors (1:80) corresponds to an absolute innervation density of around 7 times lower than in hairy skin. This sparse innervation sheds light on discrepancies between psychophysical findings of touch perception on glabrous skin and hairy skin, although the role of these CT afferents in the glabrous skin remains subject to future work. New & Noteworthy: Human touch is encoded by low-threshold mechanoreceptors, including myelinated Aβ afferents and unmyelinated C-tactile (CT) afferents. CTs are abundant in hairy skin and are thought to code gentle, stroking touch that signals positive affective interactions. CTs have never been described in human glabrous skin, yet we show evidence for their existence on the hand, albeit at relatively low density. Glabrous skin CTs may provide modulatory reinforcement of gentle tactile interactions during touch using the hands.

Cutaneous laser stimulation is a proficient tool to investigate the function of the nociceptive system. However, variations in laser–skin interactions, causes by different skin anatomies and laser wavelength, affects the robustness of nociceptor activation. Thus, thoroughly understanding how the skin is heated by a laser pulse is important to characterize the thermal response properties of nociceptors. The study aim was to investigate how skin type and laser wavelength influences nociceptor activation during laser stimulation. Ten healthy subjects were exposed to brief CO2 (low skin penetrance) and Nd:YAP (high skin penetrance) laser stimuli delivered to the dorsum and palm of the hand, using three different intensities. Reaction times and perception intensities were recorded. A computational model simulated heat transfer in the skin and nociceptor activation in different skin types across different wavelengths and intensities. Intensity ratings were significantly lower and reaction-times significantly increased for CO2 laser stimuli in the palm compared to the dorsum. This was not the case for Nd:YAP laser stimuli. The computational model showed that these differences can be explained by the different skin absorption of CO2 and Nd:YAP lasers. For CO2 laser stimuli, the thicker stratum corneum of the glabrous skin reduces nociceptor activation, whereas the high penetrating Nd:YAP laser elicits a similar nociceptor activation, irrespective of skin type. Nociceptor activation during laser stimulation highly depends on skin composition and laser wavelength, especially for lasers having a low penetrance wavelength. A computational model showed that this difference could be explained primarily due to differences in skin composition.

Ruffini's corpuscles are present as long fusiform encapsulated sensory structures in different tissues including the skin. Although physiological analyses strongly suggest their existence in glabrous digital skin, such localisation remains unconfirmed. Here, we have investigated the occurrence of typical Ruffini's corpuscles in 372 sections of human digital skin obtained from 186 subjects of both sexes and different ages (19–92 years). S100 protein, neuron‐specific enolase and neurofilament proteins were detected, and the basic immunohistochemical profile of these corpuscles was analysed. Fewer than 0.3 Ruffini's corpuscles/mm(2) were detected, with density distribution across the fingers being F4 > F3 > F2 > F1 > F5 and absolute values being F2 > F1 > F3 > F4 > F5. Axons displayed neuron‐specific enolase immunoreactivity, glial cells forming the core contained S100 protein, and the capsule was positive for CD34 but not Glut1, demonstrating an endoneurial origin. Present results demonstrate the existence of Ruffini's corpuscles in human glabrous digital skin at very low densities. Moreover, the identified Ruffini's corpuscles share the basic immunohistochemical characteristics of other dermal sensory corpuscles.

Meissner's corpuscles are generally considered to be located in the dermal papilla of hairless skin on the fingers, toes, palms, soles, lips, eyelids, nipples, and genital organs. We used hematoxylin and eosin staining to examine the distribution of Meissner's corpuscles in skin tissues of the fingertips, palms, lips, nipples, and labia majora and minora obtained from cadavers. Many Meissner's corpuscles were observed in the dermal papilla of the fingertips, whereas the palms had only 20% as many. Meissner's corpuscles were rare in the lips, nipples, and external genital organs, which have relatively high two-point discrimination. Because Meissner's corpuscles are rapidly adapting mechanoreceptors, they may quickly detect changes in tactile sensation, including two-point discrimination, in the movable glabrous skin. In conclusion, Meissner's corpuscles might be rare in non-movable glabrous skin compared to the fingertips and palms.

Objectif : Decrire les aspects epidemiologiques, cliniques et therapeutiques de la stenose uretrale a L’hopital national de Zinder (HNZ) NIGER. Patients et methodes : Il s’agissait d’une etude retrospective descriptive realisee dans le service d’Urologie de l’HNZ durant la periode de janvier 2016 a Decembre 2019. Nous avons collige 116 dossiers medicaux des patients, chez qui le diagnostic de retrecissement uretral etait pose et documente par une uretro-cystographie retrograde et mictionnelle (UCRM) et pris en charge. Resultats : Au cours de cette etude, 116 dossiers etaient retenus sur 964 interventions durant la periode soit 8, 31%.L’âge moyen des patients etait de 39,53 ans avec des extremes de 18 ans et 74 ans. Les principaux motifs de consultations etaient la dysurie (25 ,86%), la pollakiurie (15,52%), et la retention aigue dans (17,24%). L’uretro-cystographie retrograde et mictionnelle (UCRM) etait le principal examen complementaire du diagnostic. Cet examen avait permis de decouvrir, 69,3% de stenose uretrale au niveau bulbaire, 17,5% au niveau penien anterieur, 9,4% multiples, 3,8% au niveau du meat uretral. Le traitement avait consiste en une resection anastomose termino-terminale (RATT) au niveau bulbaire dans 57,21%(n=67), de dilatations uretrales (DU) aux beniques dans 19, 01% (n=22) des cas, uretroplastie en deux temps selon Johanson dans 11, 52%(n=13), de plasties par greffe de peau glabre de la crete iliaque dans 8,42% (n=10), et une meatotomie 3,45%(n=4). Apres un recul de 21 mois, les anastomoses (RATT) etaient jugees bonnes pour 61,19% (41/67). Les echecs etaient enregistres dans 16,42% (n=11) et 22,39% (n=15) etaient perdus de vue. Pour les dilatations aux beniques a 9 mois de recul, 59% (n= 13) etaient evaluees bonnes, et mauvaises dans 41% (n=9) des cas. Les plasties avec greffe etaient reussies dans 30% (n=3) des cas, et 70% (n=7) etaient des echecs. Les uretroplasties selon Johanson etaient jugees satisfaisantes a six mois de recul dans 23,07% (3/13) des cas, et non satisfaisantes dans 76,93% (10/13) des cas.Toutes les meatotomies etaient reussies (n=4). Un RPM ≤ 30 ml etait enregistre dans 55,17% des cas et ≥ 100ml dans 31,90% des cas. Quinze patients soit 12,93 etaient perdus de vue apres leur premiere evaluation. Conclusion : La stenose de l’uretre est une affection frequente dans les consultations en urologie a l’HNZ. Les patients consultent souvent au stade de complications. L’UCRM est la cle du diagnostic topographique de la lesion. La resection anastomose terminoterminale donne de bons resultats. La maitrise des plasties avec greffe de muqueuse, ou cutanee reste encore un defi dans notre contexte. Objective: To describe the epidemiological, clinical and therapeutic aspects of urethral stenosis at Zinder National Hospital (ZNH) NIGER. Patients and methods: This was a descriptive retrospective study carried out in the Department of Urology of the ZNH during the period from January 2016 to December 2019. We collected 116 medical records of patients, in whom the diagnosis of narrowed Urethral donation was performed and documented by retrograde and voiding urethro-cystography and managed. Results: During this study, 116 files were retained on 964 interventions during the period, ie 8.31%. The average age of the patients was 39.53 years with extremes of 18 and 74 years. The main reasons for consultations were dysuria (25.86%), pollakiuria (15.52%), and acute retention in (17.24%). Retrograde and voiding urethro-cystography (UC) was the main complementary diagnostic examination. This examination had revealed 69.3% urethral stenosis at the bulbar level, 17.5% at the anterior penis level, 9.4% multiple, 3.8% at the urethral meatus. The treatment consisted of resection of the end-to-end anastomosis at the bulbar level in 57.21% (n = 67), from urethral dilation to the benign in 19.01% (n = 22) of the cases, urethroplasty in two stages according to Johanson in 11.52% (n = 13), of plasties by glabrous skin graft of the iliac crest in 8.42% (n = 10), and a meatotomy 3.45% (n = 4). After a 21-month follow-up, anastomoses were considered good for 61.19% (41/67). Failures were recorded in 16.42% (n = 11) and 22.39% (n = 15) were lost to follow-up. For dilations to the benign patients at 9 months of follow-up, 59% (n = 13) were rated good, and poor in 41% (n = 9) of the cases. Plasty with grafting was successful in 30% (n = 3) of the cases, and 70% (n = 7) were failed. Johanson's urethroplasty was considered satisfactory after six months of recession in 23.07% (3/13) of the cases, and unsatisfactory in 76.93% (10/13) of the cases. All meatotomies were successful (n = 4). An RPM ≤ 30 ml was recorded in 55.17% of the cases and ≥ 100ml in 31.90% of the cases. Fifteen patients (12.93) were lost to follow-up after their first evaluation. Conclusion: Stenosis of the urethra is a common condition in consultations at the NHZ. Patients often consult for complications. The UC is the key to the topographic diagnosis of the lesion. Resection with end to end anastomosis gives good results. Plasties with mucosal or skin grafting still remain a challenge in our context.

Background The innervated radial artery superficial palmar branch (iRASP) flap was designed to provide consistent innervation by the palmar cutaneous branch of the median nerve (PCMN) to a glabrous skin flap. The iRASP flap is used to achieve coverage of diverse volar defects of digits. However, unexpected anatomical variations can affect flap survival and outcomes.Methods Cases in which patients received iRASP flaps since April 1, 2014 were retrospectively investigated by reviewing the operation notes and intraoperative photographs. The injury type, flap dimensions, arterial and neural anatomy, secondary procedures, and complications were evaluated.Results Twenty-eight cases were reviewed, and no flap failures were observed. The observed anatomical variations were the absence of a direct skin perforator, large-diameter radial artery superficial palmar branch (RASP), and the PCMN not being a single branch. Debulking procedures were performed in 16 cases (57.1%) due to flap bulkiness.Conclusions In some cases, an excessively large RASP artery was observed, even when there was no direct skin perforator from the RASP or variation in the PCMN. These findings should facilitate application of the iRASP flap, as well as any surgical procedures that involve potential damage to the PCMN in the inter-thenar crease region. Additional clinical cases will provide further clarification regarding potential anatomical variations.

Acral lentiginous melanoma is a histological subtype of cutaneous melanoma that occurs in the glabrous skin of the palms, soles and the nail unit. Although in some countries, particularly in Latin America, Africa and Asia, it represents the most frequently diagnosed subtype of the disease, it only represents a small proportion of melanoma cases in European‐descent populations, which is partially why it has not been studied to the same extent as other forms of melanoma. As a result, its unique genomic drivers remain comparatively poorly explored, as well as its causes, with current evidence supporting a UV‐independent path to tumorigenesis. In this review, we discuss current knowledge of the aetiology and diagnostic criteria of acral lentiginous melanoma, as well as its epidemiological and histopathological characteristics. We also describe what is known about the genomic landscape of this disease and review the available biological models to explore potential therapeutic targets.

Secrets of Meissner corpuscles The Meissner corpuscle, a mechanosensory end organ, was discovered more than 165 years ago and has since been found in the glabrous skin of all mammals, including that on human fingertips. Although prominently featured in textbooks, the function of the Meissner corpuscle is unknown. Neubarth et al. generated adult mice without Meissner corpuscles and used them to show that these corpuscles alone mediate behavioral responses to, and perception of, gentle forces (see the Perspective by Marshall and Patapoutian). Each Meissner corpuscle is innervated by two molecularly distinct, yet physiologically similar, mechanosensory neurons. These two neuronal subtypes are developmentally interdependent and their endings are intertwined within the corpuscle. Both Meissner mechanosensory neuron subtypes are homotypically tiled, ensuring uniform and complete coverage of the skin, yet their receptive fields are overlapping and offset with respect to each other. Science , this issue p. eabb2751 ; see also p. 1311

Recent research has shown systematic patterns of confusions between digits of the hands and feet. The present study addressed whether such confusions arise from early somatosensory maps or higher level body representations. As the glabrous and hairy skin of the hands and feet have distinct representations in somatosensory cortex, an effect arising from early somatotopic maps may show distinct patterns on each skin surface. In contrast, if the effect arises from higher level body representations which represent the digits as volumetric units, similar patterns should be apparent regardless of which side of the digit is touched. We obtained confusion matrices showing the pattern of mislocalization on the glabrous and hairy skin surfaces of the toes (Experiment 1) and fingers (Experiment 2). Our results replicated the characteristic pattern of mislocalizations found on the glabrous skin reported in previous studies. Critically, these effects were highly similar on the hairy skin surface of both the toes and fingers. Despite the pattern of mislocalizations being highly stereotyped across participants, there were consistent individual differences in the pattern of confusions across the two skin surfaces. These results suggest that mislocalizations occur at the level of individual digits, consistent with their resulting from higher level body representations. (PsycINFO Database Record (c) 2018 APA, all rights reserved).