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Background Very few studies have evaluated the global prevalence of pruritus. Objectives To assess its prevalence according to age, sex, ethnicity and geographic region. Methods An international cross-sectional study was conducted in 20 countries from January to April 2023. Participants were asked to complete a questionnaire on sociodemographics, and to confirm the presence or absence of a skin disease in the last 12 months and the presence or absence of pruritus in the last 7 days. Results The studied sample included 50 552 individuals. The worldwide prevalence of pruritus was 39.8%. The age group ≥ 65 years had the highest prevalence (43.3%). The prevalence was 40.7% among women and 38.9% among men (P < 0.001). There was no significant difference between ethnicities (P = 0.14). Compared with North America (41.2%), the prevalence of pruritus was significantly lower in Europe (35.9%, P < 0.001), Australia (38.4%, P = 0.017), East Asia (40.2%, P = 0.04) and Latin America (36.5%, P < 0.001), and higher in Africa (45.7%, P = 0.007). No significant difference was found with the Middle East (40.2%, P = 0.36). The prevalence of pruritus in BRICS countries (40.3%) was significantly higher than that in developed countries (38.7%) (P < 10– 3 ). Conclusions Out analysis is limited because there is no information about the severity or type (acute, chronic) of pruritus. The global prevalence of pruritus revealed age, sex and geographic region differences, with no ethnic differences. [ABSTRACT FROM AUTHOR]

Chronic pruritus (CP) is defined as an unpleasant sensation causing a desire to scratch and lasting > 6 weeks. It has a multifactorial etiology but is more frequently associated with chronic inflammatory dermatoses and systemic disorders. Psychogenic pruritus and neurological disorders are other less common etiologies, while, in some patients, it is idiopathic. CP appears to be processed by non-histaminergic pathway, contributing to its complexity and therapeutic challenge. Moreover, regardless of the etiology, it is multidimensional, including cognitive, motivational and affective components. There is a close link between psychological distress and pruritus, with particular clinical expression in chronic inflammatory dermatoses, involving the activation of the hypothalamic-pituitary-adrenal axis (and its cutaneous equivalent), the sympathetic nervous system, the release of hormones and peptides, the role of immune cells (T and B cells, macrophages) and immune-related cells in the skin (mast cells, dendritic cells and keratinocytes). Moreover, there is strong evidence that psychological factors influence the experience of pruritus. CP can also cause psychiatric disorders, including but not limited to anxiety and depression, and also lead to significant quality of life (QoL) impairment. Thereby, although a psychodermatological assessment should ideally be carried out in the context of a specific psychodermatology consultation, a brief mental health assessment could be part of the general dermatological approach to these patients. Considering that mental health, QoL and pruritus are closely linked, psychotherapeutic interventions and/or psychotropic drugs should thus be considered in some patients as an adjunct to the pharmacological treatment of CP. [ABSTRACT FROM AUTHOR]

Background: Skin pain in atopic dermatitis (AD) increases with disease severity and is associated with substantial quality of life (QoL) burden. Objectives: The aim of the study was to evaluate abrocitinib efficacy on skin pain and QoL in adults and adolescents with moderate-to-severe AD. Methods: This post hoc analysis included data with abrocitinib administered as monotherapy (pooled phase 2b [NCT02780167] and phase 3 JADE MONO-1 [NCT03349060] and JADE MONO-2 [NCT03575871]) or in combination with topical therapy (phase 3 JADE COMPARE [NCT03720470] and JADE TEEN [NCT03796676]). Patients received oral, once-daily abrocitinib 200 mg, abrocitinib 100 mg, or placebo for 12 or 16 weeks (JADE COMPARE). Skin pain was rated using the Pruritus and Symptoms Assessment for Atopic Dermatitis (PSAAD) skin pain Numerical Rating Scale (NRS) item ("How painful was your skin over the past 24 h?") on a scale from 0 (not painful) to 10 (extremely painful). Itch (Peak Pruritus NRS) and QoL (Dermatology Life Quality Index or Children's Dermatology Life Quality Index) were assessed. Least squares mean (LSM) change from baseline was analyzed using mixed-effects repeated measures modeling. Results: A total of 1,822 patients (monotherapy pool, n = 942; JADE COMPARE, n = 595; and JADE TEEN, n = 285) were analyzed. LSM change from baseline in PSAAD skin pain score was significantly greater with abrocitinib versus placebo from week 2 through week 12 or 16 across all 3 study populations and occurred in a dose-dependent manner. A greater proportion of patients achieved a ≥4-point improvement from baseline in PSAAD skin pain score with abrocitinib (200 mg and 100 mg) versus placebo in the monotherapy pool (56% and 38% vs. 12%; week 12), JADE COMPARE (72% and 52% vs. 26%; week 16), and JADE TEEN (51% and 60% vs. 31%; week 12). Additionally, a greater proportion of patients achieved a stringent threshold of skin pain improvement (PSAAD skin pain score <2) with abrocitinib versus placebo. Adults and adolescents who achieved a ≥4-point improvement in skin pain reported greater QoL improvement than those who did not achieve a ≥4-point improvement. A positive correlation (≥0.3) was observed between skin pain and QoL and separately between skin pain and itch across the 3 study populations. Conclusion: Abrocitinib as monotherapy or in combination with topical therapy improved skin pain and was associated with improved QoL in both adults and adolescents with moderate-to-severe AD across all evaluated studies. [ABSTRACT FROM AUTHOR]

Background Chronic kidney disease-associated pruritus (CKD-aP) is a common condition in patients treated with hemodialysis, and has a negative impact on quality of life (QoL). Due to the lack of standardized diagnostic tools and frequent underreporting, pruritus prevalence remains poorly documented. Methods Pruripreva was a prospective multicenter observational study that aimed to evaluate the prevalence of moderate to severe pruritus in a cohort of French hemodialysis patients. The primary endpoint was the rate of patients with mean Worst Itch Numerical Rating Scale (WI-NRS) score ≥4 calculated over 7 days (moderate pruritus, 4–6; severe, 7–8; very severe, 9–10). Impact of CKD-aP on QoL was analyzed according to its severity (WI-NRS), using 5-D Itch scale, EQ-5D and Short Form (SF)-12. Results Mean WI-NRS was ≥4 in 306 patients (mean age, 66.6 years; male, 57.6%) out of 1304 and prevalence of moderate to very severe pruritus was 23.5% (95% confidence interval 21.2–25.9). Pruritus was unknown prior to the systematic screening in 37.6% of patients, and 56.4% of those affected were treated for this condition. The more severe the pruritus, the poorer the QoL according to the 5-D Itch scale, EQ-5D and SF-12. Conclusion Moderate to very severe pruritus was reported in 23.5% of hemodialysis patients. CKD-aP was underrated although it is associated with a negative impact on QoL. These data confirm that pruritus in this setting is an underdiagnosed and underreported condition. There is an urgent demand for new therapies to treat chronic pruritus associated with CKD in hemodialysis patients. [ABSTRACT FROM AUTHOR]

Background: Pruritus is a frequent symptom experienced by patients with myeloproliferative neoplasms (MPN). Aquagenic pruritus (AP) is the most common type. The Myeloproliferative Neoplasm‐Symptom Assessment Form Total Symptom Score (MPN‐SAF TSS) self‐report questionnaires were distributed to MPN patients before consultations. Objectives: The aim of this study was to assess clinical incidence (phenotypical evolution and response to treatment) of pruritus, especially AP, in MPN patients during their follow‐ups. Patients and Methods: We collected 1444 questionnaires from 504 patients [54.4% essential thrombocythaemia (ET) patients, 37.7% polycythaemia vera (PV) patients, and 7.9% primary myelofibrosis (PMF) patients]. Results: Pruritus was reported by 49.8% of the patients, including 44.6% of AP patients, regardless of type of MPN or driver mutations. Patients suffering from pruritus were more symptomatic and had a higher rate of evolution into myelofibrosis/acute myeloid leukaemia (19.5% vs. 9.1%, OR = 2.42 [1.39; 4.32], p = 0.0009) than MPN patients without pruritus. Patients with AP had the highest pruritus intensity values (p = 0.008) and a higher rate of evolution (25.9% vs. 14.4%, p = 0.025, OR = 2.07) than patients with non‐AP. Disappearance of pruritus was observed in only 16.7% of AP cases, compared to 31.7% of cases with other types of pruritus (p < 0.0001). Ruxolitinib and hydroxyurea were the most effective drugs to reduce AP intensity. Conclusions: In this study, we demonstrate the global incidence of pruritus across all MPN. Pruritus, especially AP, which is a major constitutional symptom observed in MPN, should be assessed in all MPN patients due to higher symptom burden and higher risk of evolution. [ABSTRACT FROM AUTHOR]

(a) Number of ambulatory visits (n = 441), inpatient stays (n = 339) and inpatient stay days (n = 166) per patient due to chronic prurigo in per cent and absolute numbers. y-axis: number of patients. Dermatologists treating adult CPG patients at 14 dermatological centres across 12 European countries completed a questionnaire for each patient. Chronic prurigo (CPG) is a highly pruritic, debilitating disease,[1] complex to treat,[2] with an estimated prevalence of 8.4-210/100,000.[3] Patients are mostly treated by dermatologists and general practitioners, with 33.8% of patients receiving at least one systemic and 45.1% one topical prescription drug.[4] We investigated healthcare utilization and treatment patterns across Europe in a prospective, multicentre study. [Extracted from the article]

Itch is a common sensation which is amenable to disabling patients' life under pathological and chronic conditions. Shared assertion easily limits itch to chemical itch, without considering mechanical itch and alloknesis, its pathological counterpart. However, in recent years, our understanding of the mechanical itch pathway, particularly in the central nervous system, has been enhanced. In addition, Merkel complexes, conventionally considered as tactile end organs only responsible for light touch perception due to Piezo2 expressed by both Merkel cells and SA1 Aβ‐fibres ‐ low threshold mechanical receptors (LTMRs) ‐, have recently been identified as modulators of mechanical itch. However, the tactile end organs responsible for initiating mechanical itch remain unexplored. The consensus is that some LTMRs, either SA1 Aβ‐ or A∂‐ and C‐, are cutaneous initiators of mechanical itch, even though they are not self‐sufficient to finely detect and encode light mechanical stimuli into sensory perceptions, which depend on the entire hosting tactile end organ. Consequently, to enlighten our understanding of mechanical itch initiation, this article discusses the opportunity to consider Merkel complexes as potential tactile end organs responsible for initiating mechanical itch, under both healthy and pathological conditions. Their unsuspected modulatory abilities indeed show that they are tuned to detect and encode light mechanical stimuli leading to mechanical itch, especially as they host not only SA1 Aβ‐LTMRs but also A∂‐ and C‐fibres. [ABSTRACT FROM AUTHOR]

There are no previous studies of the psychopathology associated with different aetiologies of chronic pruritus. A systematic review was performed of cohort and case-control studies comparing healthy controls with patients with chronic pruritus related to primary dermatoses, systemic diseases, psychogenic pruritus, idiopathic pruritus, prurigo nodularis and/or lichen simplex chronicus. The review was registered in PROSPERO and performed according to the PRISMA statement, which allowed the inclusion of 26 studies. The quality of eligible studies was assessed using the modified Newcastle-Ottawa Scale. Most of the studies concern primary dermatoses and systemic diseases. Sleep disorders are a common comorbidity interrelated with pruritus, anxiety and depressive symptoms, in primary dermatoses. Sleep disorders are linked with pruritus and depressive symptoms in end-stage renal disease and hepatobiliary disease. Depressive and anxiety symptoms are associated with psychogenic pruritus. Psychogenic pruritus, lichen simplex chronicus and some primary dermatoses are linked with personality characteristics. Further studies are required to explore in depth the psychopathology linked with psychogenic pruritus and prurigo nodularis, as well as psychopathology linked with other primary dermatoses and systemic disorders associated with chronic pruritus, and to better differentiate psychogenic pruritus from psychopathological characteristics linked with other aetiologies of chronic pruritus, in order to improve the management of patients with chronic pruritus. [ABSTRACT FROM AUTHOR]

Perceived stigmatization places a large psychosocial burden on patients with some skin conditions. Little is known about the experience of stigmatization across a wide range of skin diseases. This observational crosssectional study aimed to quantify perceived stigmatization and identify its predictors among patients with a broad spectrum of skin diseases across 17 European countries. Self-report questionnaires assessing perceived stigmatization and its potential predictors were completed by 5,487 dermatology outpatients and 2,808 skin-healthy controls. Dermatological diagnosis, severity, and comorbidity were clinician-assessed. Patients experienced higher levels of perceived stigmatization than controls (p<0.001, d =0.26); patients with psoriasis, atopic dermatitis, alopecia, and bullous disorders were particularly affected. Multivariate regression analyses showed that perceived stigmatization was related to sociodemographic (lower age, male sex, being single), general health-related (higher body mass index, lower overall health), disease-related (higher clinician-assessed disease severity, presence of itch, longer disease duration), and psychological (greater distress, presence of suicidal ideation, greater body dysmorphic concerns, lower appearance satisfaction) variables. To conclude, perceived stigmatization is common in patients with skin diseases. Factors have been identified that will help clinicians and policymakers to target vulnerable patient groups, offer adequate patient management, and to ultimately develop evidence-based interventions. [ABSTRACT FROM AUTHOR]

Background: The prevalence and impact of pruritus, pain, and other sensory symptoms in skin diseases are poorly known. Objective: To assess the frequency of these symptoms with dermatoses and their association with depression using data from the "Objectifs Peau" survey. Methods: A representative sample of 20,012 French individuals was created using the usual quota method. Results: When patients suffered from both pruritus and skin pain, they had a higher relative risk of psychological suffering (2.9) than those who suffered only from pruritus (1.4) or skin pain (1.2). Pruritus was reported in 48.55% of patients with acne, 43.24% with mycoses, 44.35% with warts, and 36.51% with rosacea. For skin pain, the results were 11.22%, 27.59%, and 16.13% for atopic dermatitis, acne, and warts, respectively. Other unpleasant sensations, such as tingling or burning, were also frequently reported. Conclusion: Pruritus, pain, or other sensory symptoms were found to be common not only in classic pruritic skin diseases but also in acne, rosacea, or warts. The association of pruritus and pain dramatically increased psychological suffering. These symptoms must be systematically searched for in patients, especially since new therapeutic possibilities are emerging for the symptomatic treatment of pruritus. [ABSTRACT FROM AUTHOR]

Cholestatic itch is a disabling symptom that may be secondary to liver or biliary diseases. Management of cholestatic pruritus is complex. A systematic review and meta-analysis on the efficacy of treatments for cholestatic pruritus were performed. PubMed and Cochrane Library were searched using the algorithm "(hepatitis OR cholestatic OR liver) AND (pruritus OR itch) AND (management OR treatment OR treatments)" for 1975-2019. Of the 2,264 articles identified, 93 were included in a systematic review and 15 in a meta-analysis (studies evaluating pruritus with a visual analogue scale). Some treatments act by reducing levels of pruritogens in the enterohepatic cycle, others modify the metabolism or secretion of these pruritogens, or act on pruritus pathways. A further possible treatment is albumin dialysis. However, due to many heterogeneities in the reviewed studies it is difficult to identify and recommend an optimum treatment. Only 15 studies were included in the meta-analysis, due to the small number of randomized studies using a visual analogue scale. [ABSTRACT FROM AUTHOR]

Until recently, itch pathophysiology was poorly understood and treatments were poorly effective in relieving itch. Current progress in our knowledge of the itch processing, the numerous mediators and receptors involved has led to a large variety of possible therapeutic pathways. Currently, inhibitors of IL‐31, IL‐4/13, NK1 receptors, opioids and cannabinoids, JAK, PDE4 or TRP are the main compounds involved in clinical trials. However, many new targets, such as Mas‐related GPCRs and unexpected new pathways need to be also explored. [ABSTRACT FROM AUTHOR]

Background Skin pain is a common and burdensome symptom of atopic dermatitis (AD), and its severity increases with disease progression. The Pruritus and Symptoms Assessment for Atopic Dermatitis (PSAAD) is a validated 11-item patient-reported instrument developed in accordance with regulatory agency guidance for assessment of the daily symptoms of patients with AD, including skin pain. Objective To establish content validity and evaluate the psychometric properties of the skin pain numerical rating scale (NRS) item of the PSAAD. Methods: The skin pain NRS is a single-item measure from the PSAAD and is used to assess skin pain severity over the past 24 hours with the question "How painful was your skin over the past 24 hours?" on a 10-point scale from 0 (not painful) to 10 (extremely painful). A qualitative validation analysis consisting of concept elicitation (CE) interviews; electronic completion of the PSAAD measure, including the skin pain NRS; and cognitive debriefing (CD) interviews was conducted for adults and adolescents with mild-to-severe AD. Evaluation of psychometric properties of the skin pain NRS--including test-retest reliability, estimation of meaningful within-patient change (MWPC), known-group validity, ability to detect change, construct validity, quality of completion, and ceiling and floor effects--was conducted based on a post hoc qualitative and quantitative analysis of pooled data, with skin pain NRS as part of the PSAAD in the abrocitinib monotherapy phase 3 trials JADE MONO-1 (NCT03349060) and JADE MONO-2 (NCT03575871). Data from patients (≥12 years of age) with moderate-to-severe AD were pooled across all treatment arms. Results: Among 30 CE interviews (adolescents [12-17 years], n=15; adults [≥18 years], n=15) conducted over 2 rounds of testing, 20 of 30 (67%) patients reported skin pain. During CD interviews (n=30), 100% of patients interpreted the skin pain NRS item as intended, and 73% reported it as relevant. The psychometric validation analysis included 736 patients (JADE MONO-1, N=347; JADE MONO-2, N=389). The test-retest reliability of the skin pain NRS was evidenced by large intraclass correlation coefficients (ICC; 0.76 and 0.72 in JADE MONO-1 and MONO-2, respectively) for a single daily skin pain score, which increased to 0.93 and 0.91 for a measurement averaging at least 4 scores per week. Convergent validity was demonstrated by correlations between skin pain and other clinician- and patient-reported AD measures (median correlation >0.4 starting at week 4). The skin pain NRS distinguished between "clear" and "severe" disease severity groups, assessed using the Patient Global Assessment (PtGA) and Investigator's Global Assessment (IGA) as continuous and categorical anchors (P<0.0001); differences were also significant among other disease severity groups using the PtGA and IGA as continuous anchors (P<0.0001). Based on the PtGA and IGA anchor analysis, the estimated MWPC was 1.9 and ranged from 2.7 to 3.9 points using the empirical cumulative distribution function analysis. Ability to detect change was demonstrated by linear relationships between disease severity measures and skin pain scores (correlation of ≥0.5 between the skin pain NRS and the PtGA). More than 90% of patients provided at least 4 daily skin pain scores each week. No floor or ceiling effects were observed. Conclusions: The qualitative and quantitative data from initial PSAAD development and psychometric evaluation of the skin pain NRS from the PSAAD support its content validity, reliability, construct validity, and ability to detect change. These findings corroborate the 4-point improvement in skin pain as the adequate and meaningful cut-off to define a skin pain responder in JADE MONO-1 and MONO-2. [ABSTRACT FROM AUTHOR]

Objective: Pruritus is an important symptom frequently accompanying various inflammatory skin conditions and some recent data indicated that it may be associated with autoimmune connective tissue diseases. The aim of this study was to assess the frequency and clinical presentation of itch in CLE. Methods: A multinational, prospective, cross-sectional study was performed to assess the prevalence, intensity and clinical characteristic of pruritus in various subtypes of CLE. A total of 153 patients with active CLE lesions were included. Their age ranged between 17 and 82 years (mean 49.8 ± 15.4 years), and 115 patients (75.2%) were women. The disease activity and damage were assessed according to the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI). Pruritus severity was assessed with Numeric Rating Scale (NRS) and the 12-Item Pruritus Severity Scale. Dermatology Life Quality Index and EQ-5D questionnaire were used to measure quality of life. Results: Pruritus was present in 116 (76.8%) of patients of whom half had NRS scoring equal or above 4 points indicating moderate or severe pruritus. Most commonly itch was localized on the scalp, face (excluding ears and nose) and arms (40.5%, 36.2%, 31.9%, respectively). Sensations connected with pruritus were most frequently described as burning, tingling and like ants crawling feeling, but 31.9% patients described it as "pure itch". More than half of patients reported that pruritus was present every day, and it was most frequent during the evenings. The pruritus scoring and the CLASI activity score were significantly correlated (r = 0.42, p = 0.0001), while no correlation was found with the CLASI damage score (p = 0.16). Both the maximum and average itch intensity were correlated with systemic lupus erythematosus (SLE) activity measured with the Systemic Lupus Erythematosus Disease Activity Index. Conclusions: Pruritus is a common, but frequently overlooked symptom of CLE. Its intensity correlates with the activity of CLE, but not with the skin damage. In more than a half of patients it occurs on a daily basis. The correlation between the intensity of pruritus and the activity of the skin lesions and the systemic involvement indicate that pruritus could be an individual indicator of both SLE and CLE activity. [ABSTRACT FROM AUTHOR]

Introduction: Previous studies showed more sleep disturbance (SD) in patients with cutaneous disorders (CD). During CD, unpleasant subjective symptoms [USS], such as itch, pain and others (tingling, burning, or tightness) have a negative influence on sleep quality. This study aims to evaluate the prevalence of SD in CD patients and to identify the influence of itch, pain and other unpleasant sensations on SD. Materials and Methods: An international, anonymized real-life survey was conducted with individuals [18− 75 years], with physician-confirmed CD, or without CD. The 25 items covered sociodemographic characteristics, feeling of overall sleep quality and skin unpleasant sensations. Severity of SD and unpleasant sensations were assessed using a 10-cm Visual Analogue Scale (VAS). Results: From 3834 analyzed questionnaires, 2871 (67.3%) were in the CD group and 863 (32.7%) in the control group. Patients with CD had significantly more SD (71.2% vs 32.7% in the control group, p< 0.0001). CD patients without any reported unpleasant sensation were at higher risk for SD than control subjects (OR 1,362 [95% CI 1.975– 2.405] p=0.0013). SS were highly associated with SD (OR 1.641 [95% CI 1.393– 1.933] p< 0.0001). Pruritus, pain and intermediate sensations were significant predictors of SD, with odds ratios of 1.670, 1.625 and 1.326, respectively. VAS sleep scores were strongly associated with pruritus (r: 0.25, p< 0.0001) and pain (r: 0.25 p< 0.0001) severity ratings. Discussion: SD is a common problem for patients with CD. Patients with subjective symptoms suffer more from SD, suggesting that they are aggravating factors, but are likely not the only reason for SD in CD patients. We found that during CD, intermediate sensations also contribute to SD. Despite some limitations and the potential bias due to the study design, our results confirm for the first time on an international level the influence of subjective symptoms on sleep quality in patients with CD. [ABSTRACT FROM AUTHOR]

Intra‐epidermal nerve endings, responsible for cutaneous perception of temperature, pain and itch, are conventionally described as passing freely between keratinocytes, from the basal to the granular layers of the epidermis. However, the recent discovery of keratinocyte contribution to cutaneous nociception implies that their anatomical relationships are much more intimate than what has been described so far. By studying human skin biopsies in confocal laser scanning microscopy, we show that intra‐epidermal nerve endings are not only closely apposed to keratinocytes, but can also be enwrapped by keratinocyte cytoplasms over their entire circumference and thus progress within keratinocyte tunnels. As keratinocytes must activate intra‐epidermal nerve endings to transduce nociceptive information, these findings may help understanding the interactions between the keratinocytes and nervous system. The discovery of these nerve portions progressing in keratinocyte tunnels is a strong argument to consider that contacts between epidermal keratinocytes and intra‐epidermal nerve endings are not incidental and argue for the existence of specific and rapid paracrine communication from keratinocytes to sensory neurons. [ABSTRACT FROM AUTHOR]

Barrier damage, dry skin and itch are intricately linked and form the basis of many common skin diseases. Damage from environmental insults, or genetic or inflammatory causes, can impair the skin barrier, resulting in an increase in transepidermal water loss and activation of itch-associated nerve fibres. The itch-scratch cycle can perpetuate skin barrier damage and itch. Topical therapeutic strategies are utilised to overcome dry skin and itch, primarily in the form of emollients. Recent advances in our understanding of the mechanisms underlying itch have enabled the development of new topical therapies, which may be incorporated into existing treatment regimes. Ultimately, treatment of dry skin and itch must be highly tailored to the individual according to their needs. [ABSTRACT FROM AUTHOR]

Sensitive skin is defined by the occurrence of unpleasant sensations such as tingling, burning, tautness, itching or pain. Mechanisms explaining sensitive skin are controversial, and many hypotheses have been proposed. Because sensitive skin is primarily characterized by a wide variety of neuropathic‐like symptoms, it is highly likely that neurosensory dysfunction in the skin represents one of the pathological mechanisms of sensitive skin. This hypothesis does not exclude other explanations like role of keratinocyte, transient receptor potential channels, vasculature or environmental factors. Nevertheless, the role of the nervous system in the development of sensitive skin is crucial, and growing evidence supports this hypothesis. Pain and pruritus described by patients with sensitive skin correspond to neuropathic component, and its assessment shows an increase in neuropathic measures (DN‐4, Douleur Neuropathique 4) compared with control. These sensations are similar to the sensations observed in small‐fibre neuropathy (SFN), which is a group of disorders that affect thin nerve fibres. One study on the pathophysiology of sensitive skin demonstrated that intra‐epidermal nerve fibre density, especially of peptidergic C‐fibres, was lower in the sensitive skin group. A recent study showed a modification in heat‐pain detection threshold in patients with sensitive skin. All these results indicate that C‐fibre damage can help explain sensitive skin. Consequently, the role of the nervous system is increasingly obvious. Nevertheless, keratinocytes and other epidermal cells closely participate in sensory transduction. Therefore, the results of neurophysiological studies should be interpreted in the light of this information that the whole epidermis represents a huge polymodal nociceptor. [ABSTRACT FROM AUTHOR]

Skin pain is a common and bothersome symptom of atopic dermatitis (AD) that is associated with a substantial burden. To assess the efficacy of abrocitinib vs. dupilumab on skin pain in patients with moderate-to-severe AD. Data from patients aged ≥18 years who received oral abrocitinib 200 mg once daily (QD) or subcutaneous dupilumab 300 mg once every 2 weeks in combination with topical therapy in the phase 3 trials JADE COMPARE (NCT03720470) and JADE DARE (NCT04345367) were analysed. Data from patients who received abrocitinib 100 mg QD or placebo in the JADE COMPARE trial were also included in this analysis. Patients rated their skin pain using the Skin Pain Numerical Rating Scale (NRS) item of the Pruritus and Symptoms Assessment for Atopic Dermatitis (PSAAD) instrument ['How painful was your skin over the past 24 h?' on a scale from 0 (not painful) to 10 (extremely painful) ] in JADE COMPARE or the Skin Pain Numerical Rating Scale [SP-NRS, which queried patients for the severity of their 'worst skin pain' in the past 24 h on a scale from 0 (no skin pain) to 10 (worst skin pain imaginable)] in JADE DARE. Least squares mean (LSM) changes from baseline and proportions of patients who achieved a ≥4-point improvement from baseline in PSAAD skin pain score or SP-NRS were assessed through Week 16 (JADE COMPARE) or Week 26 (JADE DARE). The JADE COMPARE analysis (Skin Pain NRS item of the PSAAD) was performed post hoc, whereas the JADE DARE analysis (SP-NRS) was prespecified. At Week 2 of JADE COMPARE, LSM change from baseline in PSAAD skin pain score was greater with abrocitinib 200 mg [−2.8 (95% CI, −3.1, −2.5)] than with abrocitinib 100 mg [−2.1 (−2.3, −1.8)], dupilumab [−2.0 (−2.3, −1.8)], or placebo [−1.3 (−1.6, −0,9)]; improvements were sustained through Week 16 of treatment with abrocitinib 200 mg [−4.1 (−4.4, −3.8)], abrocitinib 100 mg [−3.3 (−3.6, −3.0)] and dupilumab [−4.0 (−4.2, −3.7)] compared with placebo [−1.8 (−2.2, −1.4)]. In JADE DARE, LSM change from baseline in SP-NRS was significantly greater with abrocitinib 200 mg vs. dupilumab at Week 2 [−3.7 (−3.9, −3.4) vs. −2.6 (−2.8, −2.3); P < 0.0001] and week 12 [−4.5 (−4.7, −4.2) vs. −4.0 (−4.3, −3.8); P = 0.0116]; no significant differences were observed between the treatment arms at Week 16 [−4.4 (−4.7, −4.2) vs. −4.2 (−4.4, −4.0); P = 0.16], Week 20 [−4.8 (−5.0, −4.5) vs. −4.5 (−4.7 vs. −4.2); P = 0.06] or Week 26 [−4.5 (−4.8, −4.3)] vs. −4.3 (−4.6, −4.1); P = 0.27]. The proportions of patients who achieved a ≥4-point improvement in PSAAD skin pain score at week 2 of JADE COMPARE were greater with abrocitinib 200 mg (43%) than with abrocitinib 100 mg (23%), dupilumab (24%) or placebo (14%). At Week 16, these proportions increased to 76% (abrocitinib 200 mg), 57% (abrocitinib 100 mg) and 70% (dupilumab) compared with placebo (29%). In JADE DARE, the proportions of patients who achieved a ≥4-point improvement in SP-NRS were significantly greater with abrocitinib 200 mg vs. dupilumab at Week 2 (58% vs. 36%; P < 0.0001) and Week 12 (71% vs. 61%; P = 0.0098) but not at subsequent timepoints. Similar to previous findings on the effect of abrocitinib on itch, these results suggest that abrocitinib 200 mg provides greater early skin pain relief in patients with moderate-to-severe AD compared with dupilumab, but the difference between the treatments diminishes with time. At earlier time points, skin pain improvement with abrocitinib 100 mg was similar to that with dupilumab. [ABSTRACT FROM AUTHOR]

Pruritus in autoimmune and inflammatory dermatoses is a common symptom that can be severe and affect the quality of life of patients. In some diseases, pruritus is related to disorders activity and severity or may occur independent of the disease. Despite the high prevalence, the symptom is still underrated and there are only a few trials investigating the efficacy of drugs for disease-specific pruritus. In this review, the characteristics and possible pathomechanisms of pruritus in various dermatoses like autoimmune bullous diseases, connective tissue diseases as well as autoimmune-associated dermatoses (atopic dermatitis, psoriasis vulgaris) is illustrated. Additionally, studies analyzing the antipruritic treatment are discussed. Summarizing, the prevalence of pruritus in these diseases demonstrates the importance for symptom recognition and the need for an efficient antipruritic therapy. [ABSTRACT FROM AUTHOR]

Atopic dermatitis (AD) is an inflammatory, pruritic, chronic or chronically relapsing skin disease that typically begins in early childhood and is occurring frequently in families with other atopic diseases (bronchial asthma and/or allergic rhino-conjunctivitis). Thanks to immunological and neurobiological research, the era of new treatments is coming as well as it occurred with psoriasis 15 years ago. Many treatments targeting cytokines (IL-4, IL-13, IL-31, TSLP) or neurotransmitters (substance P, opioids) or their respective receptors as well as phosphodiesterase-4 or the Jak/Stat pathways are under development. Antagonists of cytokines and anti-jak have promising effects on pruritus while it is more difficult to discriminate the effects of other drugs from the placebo effect on itch, which is known to be high. [ABSTRACT FROM AUTHOR]

Pruritus is a frequent symptom in medicine. Population-based studies show that every 5th person in the general population has suffered from chronic pruritus at least once in the lifetime with a 12-month incidence of 7%. In patient populations its frequency is much higher depending on the underlying cause, ranging from around 25% in haemodialysis patients to 100% in skin diseases such as urticaria and atopic dermatitis (AD). Pruritus may be the result of a dermatological or non-dermatological disease. Especially in non-diseased skin it may be caused by systemic, neurological or psychiatric diseases, as well as being a side effect of medications. In a number of cases chronic pruritus may be of multifactorial origin. Pruritus needs a precise diagnostic work-up. Management of chronic pruritus comprises treatment of the underlying disease and topical treatment modalities, including symptomatic antipruritic treatment, ultraviolet phototherapy and systemic treatment. Treating chronic pruritus needs to be targeted, multimodal and performed in a step-wise procedure requiring an interdisciplinary approach. We present the updated and consensus based (S2k) European guideline on chronic pruritus by a team of European pruritus experts from different disciplines. This version is an updated version of the guideline that was published in 2012 and updated in 2014 (www.euroderm. org). [ABSTRACT FROM AUTHOR]

The objective of this study was to explore characteristics of pruritus in atopic dermatitis (AD) in relation to the severity of AD. A web-questionnaire was used, which included the Patient-Oriented SCORing Atopic Dermatitis index, the 5-D itch scale and the Brest questionnaire. A total of 170 participants were included (86.5% women, mean age 30.9 years). Severity of AD was mild for 8.2% of patients, moderate for 38.2% and severe for 53.5%. Mean 5-D itch scale was 13.2. The mean intensity of pruritus was 5.8, and mean sleep loss was 4.7 (from 0 to 10). The participants frequently described burning (61.8%) and stinging (58.8%); these symptoms suggest a neuropathic component. Pruritus was worse in severe AD compared with moderate AD, exhibiting a higher impact on sleep and more associated symptoms. The majority of participants reported sleep disturbance as a result of pruritus. The characteristics of pruritus varied depending on the severity of AD. [ABSTRACT FROM AUTHOR]

Itch is an unpleasant symptom, affecting many dermatological patients. Studies investigating the occurrence and intensity of itch in dermatological patients often focus on a single skin disease and omit a control group with healthy skin. The aim of this multi-centre study was to assess the occurrence, chronicity and intensity (visual analogue scale 0-10) of itch in patients with different skin diseases and healthy-skin controls. Out of 3,530 dermatological patients, 54.3% reported itch (mean ± standard deviation itch intensity 5.5 ± 2.5), while out of 1,094 healthy-skin controls 8% had itch (3.6 ± 2.3). Chronic itch was reported by 36.9% of the patients and 4.7% of the healthy-skin controls. Itch was most frequent (occurrence rates higher than 80%) in patients with unclassified pruritus, prurigo and related conditions, atopic dermatitis and hand eczema. However, many patients with psychodermatological conditions and naevi also reported itch (occurrence rates higher than 19%). [ABSTRACT FROM AUTHOR]

Atopic dermatitis (AD) is a chronic inflammatory skin disease associated with itch, eczematous lesions and impaired quality of life (QoL). Although the frequency of skin pain in AD is often underestimated, it is associated with a substantial health burden, similar to itch and is known to contribute to sleep disruption and mood disturbance. Abrocitinib is an oral, once-daily, selective Janus kinase-1 inhibitor approved for the treatment of moderate-to-severe AD. In phase 3 clinical trials JADE MONO-1 (NCT03349060) and JADE MONO-2 (NCT03575871), abrocitinib demonstrated rapid relief from itch and skin pain, as well as meaningful improvements in QoL compared with placebo. The interrelationships between abrocitinib treatment and improvements in itch, skin pain and QoL have not yet been investigated. This mediation analysis aimed to characterize the effect of abrocitinib treatment via itch and skin pain on dermatology-specific QoL in patients with AD. Data from JADE MONO-1 and JADE MONO-2 were pooled in this analysis. Adult patients with moderate-to-severe AD received abrocitinib (200 or 100 mg) as monotherapy or placebo for 12 weeks. Three separate models were evaluated whereby QoL was assessed using the Dermatology Life Quality Index (DLQI) score, and itch and skin pain were assessed via the Pruritus and Symptoms Assessment for Atopic Dermatitis (PSAAD) items #1 (How itchy was your skin over the past 24 h?) and #2 (How painful was your skin over the past 24 h?), respectively. The cross-sectional mediation model (CSMM) was run separately at weeks 2, 4, 8 and 12 using all available data at each timepoint. The longitudinal mediation model (LMM), which does not assume independence among measurements of itch, skin pain and DLQI at each timepoint, estimated relationships using all available data from all weeks simultaneously. Based on the results of the CSMM and LMM, a pseudosteady-state model, in which the relationship among variables was assumed to be the same across timepoints, was applied. Effects with P<0.05 were considered statistically significant. In the CSMM, the indirect effect of abrocitinib on DLQI mediated via itch was considered approximately stable (24–30%) for the first 8 weeks before increasing at week 12 (42%), while the indirect effect mediated via skin pain was considered approximately stable from week 2 to week 12 (33–41%). In the LMM, the indirect effect of abrocitinib treatment on DLQI mediated via both itch and skin pain was considered approximately stable from week 2 to week 12 (17–26% and 42–48%, respectively). The cross-sectional and longitudinal models were generally consistent and indicated a pseudo-steady-state period between weeks 2 and 12. Using the pseudo-steady-state model, the direct effect of abrocitinib on DLQI was estimated to be 34.8% (P<0.0001), and the indirect effects mediated via itch and skin pain were estimated to be 19.5% and 45.8%, respectively (P≤0.0001 for both). Improvements in dermatology-specific QoL with abrocitinib are mostly mediated indirectly via a reduction in skin pain and less so by relief of itch. These findings warrant further research to examine to what extent patients consider itch and skin pain as separate concepts in terms of their impact on dermatology-specific QoL. [ABSTRACT FROM AUTHOR]

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by intense itch, skin pain and impaired quality of life. Skin pain is a common and bothersome symptom of AD and increases in prevalence and intensity with worsening disease severity. Abrocitinib is an oral, once-daily, selective Janus kinase-1 inhibitor approved for the treatment of moderate-to-severe AD. Abrocitinib treatment resulted in improvements in skin clearance as well as rapid itch reduction in patients with moderate-to-severe AD across multiple phase 3 studies. Work productivity loss and activity impairment were assessed in the phase 3 JADE MONO-2 (NCT03575871) trial, with greater improvements being associated with abrocitinib treatment compared with placebo. The mechanism(s) through which abrocitinib reduces work productivity loss and activity impairment are unclear. To describe the interrelationships among abrocitinib treatment, itch, skin pain, and work productivity and activity impairment using a mediation modelling analysis in patients with AD. Data from adult patients treated with abrocitinib monotherapy (200 or 100 mg) or placebo in JADE MONO-2 were included in this analysis. As separate outcomes, work productivity loss and activity impairment (outcome variables) were measured by the Work Productivity and Activity Impairment Questionnaire: Atopic Dermatitis version 2.0 (WPAI-AD 2.0). Itch and skin pain (mediator variables) were evaluated using the Pruritus and Symptoms Assessment for Atopic Dermatitis (PSAAD) item #1 (How itchy was your skin over the past 24 h?) and item #2 (How painful was your skin over the past 24 h?), respectively. Mediation modelling was conducted independently for work productivity loss and activity impairment. All available data at week 12 were used in the modelling. Effects with P<0.05 were considered statistically significant. The direct effects of abrocitinib were estimated to be 7.3% (P=0.779) and 17.5% (P=0.258) on work productivity loss and activity impairment, respectively. The indirect effects of abrocitinib treatment on work productivity loss and, separately, on activity impairment mediated via itch were estimated to be 50.6% (P=0.017) and 20.9% (P=0.062), respectively, and via skin, pain were estimated to be 42.1% and 61.5%, respectively, (P<0.05 for both). The indirect effect of abrocitinib treatment on work productivity loss is mediated approximately equally through the reduction in itch severity and skin pain. The effect of abrocitinib treatment on activity impairment is mostly mediated indirectly through the reduction of skin pain, along with a smaller indirect contribution from the reduction in itch. These findings support further research into the extent that patients consider itch and skin pain as separate concepts in terms of their impact on work productivity. [ABSTRACT FROM AUTHOR]

Pruritus is a frequent symptom in systemic sclerosis (SSc), with a prevalence of 40-65%, but its pathophysiology is poorly understood. This study investigated the immunological component of pruritus. Fiftysix patients with SSc responded to a standardized questionnaire regarding both SSc disease and pruritus characteristics. Among patients with SSc, those with pruritus did not display a particular immunological profile (inflammatory, humoral, and/or cellular factors), but pruritus was, in most cases, concomitant with the development of SSc. Thus, pruritus characteristics were evaluated further, according to the detection of anticentromere autoantibodies (ACA), into ACA+ (n = 17) and ACA-- (n = 19). The ACA+ subgroup was characterized by a longer evolution of SSc and pruritus, pruritus present outside the sclerotic area, and a shorter daily duration of pruritus. In conclusion, the concomitant appearance of the 2 processes and the differences observed between ACA+ and ACA-- subgroups support the presence of an immunological component in pruritus. [ABSTRACT FROM AUTHOR]

Pruritus is an important symptom frequently accompanying various inflammatory skin conditions. Some recent data have indicated that it may also be associated with autoimmune connective tissue diseases, including systemic sclerosis and dermatomyositis; however, studies on the prevalence and clinical characteristics of pruritus in CLE are limited. We have performed a multinational, prospective, cross-sectional study in order to assess the prevalence and intensity of pruritus in adult patients suffering from various subtypes of CLE. After developing a questionnaire assessing various aspects of pruritus, we have surveyed 567 patients with cutaneous involvement during the course of LE regarding the presence and intensity of pruritus. Pruritus was present in 425 of all patients (75.0%) and was most frequently reported by subjects with acute CLE (82.1%), followed by chronic CLE (78.8%), subacute CLE (65.9%), and intermittent CLE (55.6%) (p<0.001). Based on the Numerical Rating Scale, the severity of itch was mild, moderate, and severe in 264 (62.1%), 98 (23.1%), and 63 (14.8%) patients, respectively. The highest mean pruritus intensity was reported by subjects with hypertrophic LE (5.1±3.0 points) followed by generalized discoid LE (3.6±3.0 points), subacute CLE (3.0±3.0 points), chilblain LE (3.0±1.0 points), localized discoid LE (2.6±2.0 points), intermittent CLE (2.6±3.0 points), acute CLE (2.5±1.2 points), and lupus erythematosus profundus (1.9±2.7 points). In conclusion, pruritus is a frequent phenomenon in CLE; however, in most patients it is of mild severity. Further studies are needed to better characterize its clinical characteristics and influence on patients’ well-being. [ABSTRACT FROM AUTHOR]

Sensitive skin is a syndrome defined by the occurrence of unpleasant sensations (stinging, burning, pain, pruritus, and tingling sensations) in response to stimuli that normally should not provoke such sensations. The worldwide prevalence of sensitive skin is approximately 40%. Clinical, histologic, biochemical, and therapeutic data show that this condition is related to changes in epidermal nerve endings with subsequent hyperreactivity and neurogenic inflammation; hence, sensitive skin is not a psychosomatic disorder, although psychologic consequences are possible. [ABSTRACT FROM AUTHOR]

Pruritus occurs frequently in the elderly population, but it has not been fully defined and its precise prevalence is unknown. Putative causes of pruritus are numerous and patients' quality of life can be greatly reduced. In the absence of any specific cause, a diagnosis of senile pruritus is proposed, suggesting that itch is secondary to ageing. However, the relationship of pruritus with skin ageing and/or neuronal ageing and/or immune ageing is poorly understood. Many treatments have been reported, but are poorly effective. This paper reviews the literature on senile pruritus, in order to improve understanding of this condition and to enable improved diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Sensitive skin is a clinical syndrome characterized by the occurrence of unpleasant sensations, such as pruritus, burning or pain, in response to various factors, including skincare products, water, cold, heat, or other physical and/or chemical factors. Although these symptoms suggest inflammation and the activation of peripheral innervation, the pathophysiogeny of sensitive skin remains unknown. We systematically analysed cutaneous biopsies from 50 healthy women with non-sensitive or sensitive skin and demonstrated that the intraepidermal nerve fibre density, especially that of peptidergic C-fibres, was lower in the sensitive skin group. These fibres are involved in pain, itching and temperature perception, and their degeneration may promote allodynia and similar symptoms. These results suggest that the pathophysiology of skin sensitivity resembles that of neuropathic pruritus within the context of small fibre neuropathy, and that environmental factors may alter skin innervation. [ABSTRACT FROM AUTHOR]

Sensitive skin is a frequent complaint in the general population, in patients, and among subjects suffering from itch. The International Forum for the Study of Itch (IFSI) decided to initiate a special interest group (SIG) on sensitive skin. Using the Delphi method, sensitive skin was defined as "A syndrome defined by the occurrence of unpleasant sensations (stinging, burning, pain, pruritus, and tingling sensations) in response to stimuli that normally should not provoke such sensations. These unpleasant sensations cannot be explained by lesions attributable to any skin disease. The skin can appear normal or be accompanied by erythema. Sensitive skin can affect all body locations, especially the face". This paper summarizes the background, unresolved aspects of sensitive skin and the process of developing this definition. [ABSTRACT FROM AUTHOR]

Pruritus, also known as itch, is a very common, unpleasant sensation that elicits an urge to scratch. Its origin is not always in the skin, and neuropathic itch that is caused by neuronal orglial damage is common, but poorly understood by both dermatologists and neurologists. Although pruritus has not been considered as serious a symptom as pain, it is difficult to treat and--if chronic--can severely impair quality of life. Neuropathic itch is often associated with other clinical symptoms, most commonly neuropathic pain, and hypersensitization to stimuli is present in both pruritus and pain of neuropathic origin. The shared aetiology can aid in finding suitable treatment for itch in some cases, but more detailed knowledge of the mechanisms of itch, along with standardized, well-controlled trials, is needed. Pruritus research is an emerging but currently very active field, and our understanding of this sensation is rapidly increasing. Here, we review new discoveries regarding the role of the nervous system and the contribution of different pathways in pruritus, discuss the different aetiologies of neuropathic itch, and outline currently available and potential strategies for managing neuropathic pruritus. [ABSTRACT FROM AUTHOR]

The article presents the guidelines for the treatment of chronic pruritus issued by the European Dermatology Forum (EDF) and the European Academy of Dermatology and Venerology (EADV). It discusses several factors related with chronic pruritus which include clinical classification, epidemiological study and diagnostic management. It also informs about the diagnosis and treatment methods for chronic pruritus.

I would like to propose my opinions regarding whether psychogenic pruritus exists and how it could be defined. I also consider whether 'functional itch disorder' or 'somatoform itch' are more appropriate terms. In addition, we address how it can be understood, whether similar disorders exist, whether it is related to pleasure and how to diagnose and treat the patient. In our opinion, psychogenic pruritus does exist and is different from the aggravation of itch from other origins. It is aggravated by psychological factors and, therefore, it is necessary to separate the two terms. We believe that the major role of the brain in itch explains its pathophysiogeny. [ABSTRACT FROM AUTHOR]

Functional itch disorder or psychogenic pruritus is a poorly defined diagnosis. This paper sets out the proposed diagnostic criteria of the French Psychodermatology Group (FPDG). There are three compulsory criteria: localized or generalized pruritus sine materia, chronic pruritus (>6 weeks) and the absence of a somatic cause. Three additional criteria from the following seven items should also be present: a chronological relationship of pruritus with one or several life events that could have psychological repercussions; variations in intensity associated with stress; nocturnal variations; predominance during rest or inaction; associated psychological disorders; pruritus that could be improved by psychotropic drugs; and pruritus that could be improved by psychotherapies. [ABSTRACT FROM AUTHOR]

Chronic itch is a common and distressing symptom that arises from a variety of skin conditions and systemic diseases. Despite this, there is no clinically based classification of pruritic diseases to assist in the diagnosis and cost-effective medical care of patients with pruritus. The proposed classification focuses on clinical signs and distinguishes between diseases with and without primary or secondary skin lesions. Three groups of conditions are proposed: pruritus on diseased (inflamed) skin (group I), pruritus on non-diseased (non-inflamed) skin (group II), and pruritus presenting with severe chronic secondary scratch lesions, such as prurigo nodularis (group lII). The next part classifies the underlying diseases according to different categories: dermatological diseases, systemic diseases including diseases of pregnancy and drug-induced pruritus, neurological and psychiatric diseases. In some patients more than one cause may account for pruritus (category "mixed") while in others no underlying disease can be identified (category "others"). This is the first version of a clinical classification worked out by the members of the international Forum for the Study of itch. it is intended to serve as a diagnostic route for better evaluation of patients with chronic pruritus and aims to improve patients' care. [ABSTRACT FROM AUTHOR]

In infants, pruritus is frequently considered as absent because they do not scratch themselves. Because pruritus could induce severe adverse effects in this vulnerable population, we aimed to review existing evidence on the ability of young infants to experience itch and on how to assess itch-related discomfort in this population. A literature review was performed (Pubmed, Google Scholar). Neurological itch pathways are well described. Skin development starts early during gestation. At 34 weeks of gestation, skin is almost complete while skin adaptations occur after birth. Newborn skin is neurologically functional, including the ability for young infants to feel pain. Similarities and interactions between pain and pruritus support the hypothesis that infants could feel pruritus. However, the existence of pruritus in infants has never been evidenced. Many itchy conditions can affect them, suggesting non-negligible prevalence of infant pruritus among which atopic dermatitis (AD) is the most studied disease. Studies reported a negative impact of AD on children and their families. There is no existing validated method to assess pruritus in infants, although they may feel pruritus and chronic pruritus can lead to serious adverse effects. To appropriately diagnose pruritus appears of great interest among young infants. Development of a method is required to this aim. [ABSTRACT FROM AUTHOR]

Using an ex vivo skin-nerve preparation, skin and nerve cells were reconstituted into a single unit and maintained in a nutrient medium bath until required experimentally. Our objective was to use the epidermis as a relay for the induction of an electric current to the neurons following the topical application of capsaicin on the skin epidermis of the skin explant, an agonist of the TRPV1 channel implicated in pruritus and pain. After 10-20 days of coculture to form the re-innervated skin model, we applied a solution of capsaicin directly on the epidermis of the skin explant (4 μ m). The resulting current was recorded using a path-clamp technique on the neuronal fibres. Following the topical application of capsaicin, spontaneous activity was triggered, as characterised by repetitive spikes with periods of 125, 225 or 275 ms. This study demonstrates that the skin explant and nerve cells preparation may receive stimuli and be used to screen molecules or to study signal transmission. [ABSTRACT FROM AUTHOR]

The article focuses on the need of questionnaires for itching that should consider both the patient's and the doctor's perspectives as well as the need to gather important medical information. It mentions patient-doctor relationship and indispensable for clinical trials, investigations into quality of life, psychological studies and pathophysiological research. It also mentions itch is associated with pain, burning tingling, tickling, prickling, tightness or stinging.

The article discusses how learned immune function can optimize dermatological treatments through the placebo effect and nocebo effects. Topics discussed include placebo and nocebo effects being the positive or negative treatment effects that depends exclusively of the patient's expectations about a treatment outcome, its consequences for itch treatment, and meta-analysis of clinical trials of oral systemic medication showing substantial effects on itch of placebo medications.

The article discusses a study that explores the significance of itch and pain on non-melanoma skin cancers. The method of the study is presented that used patients with a skin lesion suspicious for carcinoma at the Department of Dermatology of the Military Hospital in Brest, Belarus. The results reveal that pain and itch are common symptoms of non-melanoma skin cancers and pain was more common in squamous cell carcinoma than in basal cell carcinoma.

The article discusses research concerning the characteristics of pruritus in patients with an autosomal dominant disease called neurofibromatosis (NF)1. It highlights the characterization of NF1 by tumour formation resulting to generation of neurofibromas, optic gliomas and malignant peripheral nerve tumours. Symptoms of neuropathic pruritus including allodynia, paraesthesias and hypoaesthesia, are also mentioned.

The article presents the case studies on the effectiveness of capsaicin 8% patch in treating refractory neuropathic pruritus. Topics include the amelioration experienced by the patients with neuropathic pruritus after using capsaicin patch, the effects of capsaicin patch, and the potential use of capsaicin patch in localized pruritic disorders.

The article discusses the relationship between itch and stress in patients with atopic dermatitis. Topics include effects of stress on atopic dermatitis and itch associated with the release of neuropeptides and hormones, role of serotonin in itch, critical role of dysfunctional parasympathetic nervous system in chronic itch, and randomized controlled trials revealing release of serotonin in brain after scratching.

A letter to the editor about the case of a 75-year-old French Caucasian female patient with hydroxyethyl starch-related pruritus is presented.

This article discusses a study that investigated the qualitative features of pruritus in different dermatoses including non-atopic eczema, atopic dermatitis, urticaria, psoriasis and scabies. The results revealed that heat sensations and pain are the most common symptoms accompanying itching. It also revealed the differences in associated modulating factors including sweating, physical effort and cold water.

A letter to the editor about the epidemiology of dandruff, scalp pruritus and associated symptoms is presented.