Itch threshold

The amygdala plays a key role in the processing of itch and pain signals as well as emotion. A previous study revealed that the central nucleus of the amygdala (CeA)-parabrachial nucleus (PBN) pathway is involved in pain regulation. The same pathway might also control itch. To test this possibility, prodynorphin (Pdyn)-Cre mice were used to optogenetically manipulate pdyn+ CeA-to-PBN projections. We found that optogenetic stimulation of pdyn+ amygdala neurons or pdyn+ CeA-to-PBN projections inhibited histamine- and chloroquine-evoked scratching...

BACKGROUND: Abdominal aortic aneurysm (AAA) is a life threatening vascular disease. Our previous study reported the upregulation of CD147 expression in human aortic aneurysms. OBJECTIVE: In this study, we injected apoE-/- mice intraperitoneally with CD147 monoclonal antibody or IgG control antibody to observe its effect on Angiotensin II (AngII) induced AAA formation. METHODS: ApoE-/- mice were randomly divided into an AngⅡ+CD147 antibody group (n = 20) and an AngⅡ+IgG antibody group (n = 20)...

BACKGROUND: The diagnosis of sensitive skin remains nonuniform, and the underlying mechanism is unclear. Previous studies were inconsistent in the current perception threshold (CPT) measurement for sensitive skin; thus, the neural sensitivity of sensitive skin needs to be clarified. OBJECTIVES: This study aimed to compare the CPT measurement and the cowhage test for sensitive skin and to investigate the correlation between CPT values and cowhage-itch scores...

BACKGROUND: Chronic kidney disease-associated pruritus (CKD-aP) is associated with an increased risk of depression, poor sleep and reduced health-related quality of life. Two phase III studies (KALM-1 and KALM-2) of difelikefalin showed reduced CKD-aP severity and improved itch-related health-related quality of life in patients with moderate and severe CKD-aP receiving haemodialysis for kidney failure. OBJECTIVE: We aimed to estimate the cost effectiveness of difelikefalin for patients with CKD-aP receiving haemodialysis for kidney failure compared to standard care from a UK National Health Service perspective...

AIMS: To analyze the clinical characteristics, treatment outcomes and sleep psychological problems of children and parents infected with familial aggregation Omicron variants under a parent-child ward treatment mode to provide a theoretical reference for the diagnosis and comprehensive treatment of Omicron variant strains. METHODS: The clinical data of 225 children and 230 adult family members admitted were retrospectively collected and analyzed to investigate their clinical characteristics and response to treatments...

IMPORTANCE: Prurigo nodularis (PN) is a chronic heterogeneous inflammatory skin disease. OBJECTIVE: To elucidate which components of type 2 inflammation are dysregulated systemically in PN. DESIGN: Whole blood was obtained from PN patients with uncontrolled disease and control patients without pruritus. Plasma was assayed for IL-4, IL-5, IL-13, IgE, and periostin. ANOVA was utilized to compare PN and control patients and multiple-hypothesis adjusted p- value was calculated with the significance threshold at 0...

BACKGROUND: Ensuring menstrual cup safety is paramount, yet a menstrual cup safety assessment scheme is lacking. This paper presents a quadripartite scheme, showing how it can be applied. METHODS: The Tampax Menstrual Cup was evaluated in the safety assessment scheme: (1) Biocompatibility and chemical safety of cup constituents. Extractables were obtained under different use condition; exposure-based risk assessments (EBRA) were conducted for extractables exceeding thresholds of toxicological concern...

INTRODUCTION: Itch associated with atopic dermatitis (AD) has a profoundly negative effect on patients of all ages. Therefore, itch is a main target for AD therapeutic approaches, and treatments are perceived as beneficial when they achieve an itch reduction. In the absence of a validated scale for children aged 6-11 years that is suitable for assessing itch intensity in clinical trial settings, the Worst Itch Scale was developed. METHODS: Qualitative interviews, comprising concept elicitation and cognitive debriefing, were conducted to develop and evaluate the content validity of the Worst Itch Scale...

BACKGROUND: Under the condition of stress, the hypothalamic-pituitary-adrenal axis (HPA axis) is activated and causes the secretion of corticotropin-releasing factor (CRF). Previous studies have demonstrated that CRF is involved in the regulation of pain and itch. Thus, it remains worthy to explore whether the desensitization of pain and itch under high-intensity acute stress (such as high fear and tension) is related to the sharp increase of CRF. METHODS: Forced swimming was used to simulate acute stress...

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...

RATIONALE & OBJECTIVE: Individuals with chronic kidney disease frequently suffer from chronic kidney disease-associated pruritus (CKD-aP), impacting sleep quality and quality of life (QoL) and increasing the likelihood of depression. Difelikefalin is a kappa-opioid receptor agonist recently approved in the United States for the treatment of moderate-to-severe CKD-aP in hemodialysis patients. Study 3105 was conducted to further assess the safety of difelikefalin and the effects on pruritus and QoL...

BACKGROUND: Emerging treatments for moderate-to-severe atopic dermatitis (AD) may provide greater and faster improvement in AD signs and symptoms than current therapies. OBJECTIVE: Examine JADE COMPARE (NCT03720470) data using stringent efficacy end points. METHODS: Adults with moderate-to-severe AD were randomly assigned 2:2:2:1 to receive oral abrocitinib 200 or 100 mg once daily, subcutaneous dupilumab 300 mg every 2 weeks (600-mg loading dose), or placebo, with medicated topical therapy for 16 weeks...

BACKGROUND: Transfusion-related adverse events can be unrecognized and unreported. As part of the US Food and Drug Administration's Center for Biologics Evaluation and Research Biologics Effectiveness and Safety initiative, we explored whether machine learning methods, such as natural language processing (NLP), can identify and report transfusion allergic reactions (ARs) from electronic health records (EHRs). STUDY DESIGN AND METHODS: In a 4-year period, all 146 reported transfusion ARs were pulled from a database of 86,764 transfusions in an academic health system, along with a random sample of 605 transfusions without reported ARs...

Projection neurons belonging to the anterolateral system (ALS) underlie the perception of pain, skin temperature and itch. Many ALS cells are located in laminae III-V of the dorsal horn and the adjacent lateral white matter. However, relatively little is known about the excitatory synaptic input to these deep ALS cells, and therefore about their engagement with the neuronal circuitry of the region. We have used a recently developed mouse line, Phox2a::Cre, to investigate a population of deep dorsal horn ALS neurons known as "antenna cells", which are characterised by dense innervation from peptidergic nociceptors, and to compare these with other ALS cells in the deep dorsal horn and lateral white matter...

PURPOSE OF REVIEW: Allergic conjunctivitis is highly prevalent and affects up to one third of the general population. The current understanding of the pathophysiology and therapeutic strategies center around the type 2 inflammatory pathway. However, there is an increasing body of evidence that suggests neurogenic mechanisms also play a role in allergic inflammation, with a substantial proportion of allergic conjunctivitis patients experiencing both ocular itch and pain. RECENT FINDINGS: Unmyelinated C fibres on the ocular surface transmit histaminergic itch and can be directly activated by mast cell mediators...

Somatosensory neurons have evolved to detect noxious stimuli and activate defensive reflexes. By sharing means of communication, nociceptor neurons also tune host defenses by controlling the activity of the immune system. The communication between these systems is mostly adaptive, helping to protect homeostasis, it can also lead to, or promote, the onset of chronic diseases. Both systems co-evolved to allow for such local interaction, as found in primary and secondary lymphoid tissues and mucosa. Recent studies have demonstrated that nociceptors directly detect and respond to foreign antigens, immune cell-derived cytokines, and microbes...

Chronic itch is associated with sensitization of the somatosensory nervous system. Recent studies have identified the neural circuits transmitting acute itch; however, the mechanisms by which itch transforms into a pathological state remain largely unknown. We have previously shown that Aβ low-threshold mechanoreceptors, together with spinal urocortin 3-positive (Ucn3+ ) excitatory interneurons and neuropeptide Y-positive (NPY+ ) inhibitory interneurons, form a microcircuit that transmits and gates acute mechanical itch...

Multiple cortical areas including the primary somatosensory cortex (S1) are activated during itch signal processing, yet cortical representation of itch perception remains unknown. Using novel miniature two-photon microscopic imaging in free-moving mice, we investigated the coding of itch perception in S1. We found that pharmacological inactivation of S1 abolished itch-induced scratching behavior, and the itch-induced scratching behavior could be well predicted by the activity of a fraction of layer 2/3 pyramidal neurons, suggesting that a subpopulation of S1 pyramidal neurons encoded itch perception, as indicated by immediate subsequent scratching behaviors...

OBJECTIVE: Atopic dermatitis displays a relevant sleep burden sustained by clinical (i.e., itch), psychological (i.e., inadequate coping strategies) and therapeutic (i.e., frequent loss of drug response) triggers. Dupilumab, the first biologic approved for atopic dermatitis, showed excellent effects on improving pruritus and sleep after only two weeks of treatment but, in some cases, may have paradoxical effects. The rate of sleep-related side-effects remains unknown. More specifically, adverse-drug reactions (ADRs) related to dupilumab have been investigated during the safety phase of randomized clinical trials or in small retrospective epidemiological surveys, but little is known about sleep-related ADRs in real-life settings...

BACKGROUND: Although alopecia areata (AA) greatly impacts patients' quality-of-life (QOL), there is no adequate validation of AA-targeted QOL surveys in clinical trials, hindering sufficient representation of patient-reported outcomes. OBJECTIVES: Better understanding of patient-reported outcomes may guide treatment goals and future clinical trials. METHODS: In a recent randomized-controlled trial testing dupilumab in AA, patients were administered the Alopecia Areata Quality of Life Index (AA-QLI) and the Alopecia Areata Symptom Impact Scale (AASIS) surveys, specifically evaluating QOL in AA patients...