Acupuncture for Histamine-Induced Itch: Association With Increased Parasympathetic Tone and Connectivity of Putamen-Midcingulate Cortex

Effects and safety of acupuncture versus non-penetrating sham acupuncture for senile pruritus: Rationale and design for a randomized controlled trial

Background

Senile pruritus (SP), characterized by idiopathic itch in individuals aged 60 years and older without primary skin lesions, significantly impacts sleep and quality of life. Effective alternative treatments are needed. Acupuncture has been suggested as a potential intervention to alleviate pruritus; however, its role in managing SP remains uncertain. This study aims to evaluate the efficacy and safety of acupuncture for SP.

Methods

This single-center, parallel, two-arm, randomized, sham-controlled trial will enroll 200 patients diagnosed with SP in a 1:1 ratio to either the acupuncture or sham acupuncture group, receiving acupuncture or sham acupuncture three sessions weekly for six weeks. Participants, outcome assessors, and the statisticians will be blinded. The primary outcome is the change from baseline in the Average Pruritus Numerical Rating Scale (AP-NRS) score at week 6. Secondary outcomes include changes in AP-NRS (at other timepoints), Peak Pruritus Numerical Rating Scale (PP-NRS), number of scratch episodes, itchy area of body surface, overall dry skin score (ODS), the Dermatology Life Quality Index (DLQI), the Pittsburgh Sleep Quality Index (PSQI), the Hospital Anxiety and Depression Scale (HADS), and Patient Global Impression of Change (PGIC). Long-term effects of acupuncture will also be explored. Adverse events and additional treatments will be monitored throughout the study period. The modified intention-to-treat (mITT) population which includes participants who complete baseline assessments and receive at least one treatment session will be analyzed.

Discussion

This trial represents the first rigorously designed, single-center, randomized, sham-controlled study assessing the effects and safety of acupuncture for senile pruritus. We used valid outcome measurements which can provide valuable insights into the patient's symptoms and facilitate tracking symptoms over time and evaluate treatment effectiveness. This study may provide valuable insights into the research topic and inform future research.

Ethics and dissemination

This study has received ethical approval from the Ethics Committee of Guang'anmen Hospital, China Academy of Chinese Medical Sciences (2024-087-KY).

Trial registration

Registered with ClinicalTrials.gov (NCT06506240) on July 11, 2024.

Projections from anteromedial thalamus nucleus to the midcingulate cortex mediate pain and anxiety-like behaviors in mice

Prior research has demonstrated the involvement of the midcingulate cortex (MCC) and its downstream pathway in pain regulation. However, the mechanism via which pain information is conveyed to the MCC remains unclear. The present study utilized immunohistochemistry, chemogenetics, optogenetics, and behavior detection methods to explore the involvement of MCC, anteromedial thalamus nucleus (AM), and AM-MCC pathway in pain and emotional regulation. Chemogenetics or optogenetics methods were employed to activate/inhibit MCCCaMKIIα, AMCaMKIIα, AMCaMKIIα-MCC pathway. This manipulation evokes/relieves mechanical and partial heat hyperalgesia, as well as anxiety-like behaviors. In the complete Freund,s adjuvant (CFA) inflammatory pain model, chemogenetic inhibition of the AMCaMKIIα-MCCCaMKIIα pathway contributed to pain relief. Notably, this study presented the first evidence implicating the AM in the regulation of nociception and negative emotions. Additionally, it was observed that the MCC primarily receives projections from the AM, highlighting the crucial role of this pathway in the transmission of pain and emotional information.

Efficacy of Acupuncture for Chronic Spontaneous Urticaria : A Randomized Controlled Trial

BACKGROUND

The effectiveness of acupuncture for patients with chronic spontaneous urticaria (CSU), reported in a few small-scale studies, is not convincing.

OBJECTIVE

To investigate whether acupuncture leads to better effects on CSU than sham acupuncture or waitlist control.

DESIGN

A multicenter, randomized, sham-controlled trial. (Chinese Clinical Trial Registry: ChiCTR1900022994).

SETTING

Three teaching hospitals in China from 27 May 2019 to 30 July 2022.

PARTICIPANTS

330 participants diagnosed with CSU.

INTERVENTION

Participants were randomly assigned in a 1:1:1 ratio to receive acupuncture, sham acupuncture, or waitlist control over an 8-week study period (4 weeks for treatment and another 4 weeks for follow-up).

MEASUREMENTS

The primary outcome was the mean change from baseline in the Weekly Urticaria Activity Score (UAS7) at week 4. Secondary outcomes included itch severity scores, self-rated improvement, and Dermatology Life Quality Index scores.

RESULTS

The mean change in UAS7 (range, 0 to 42) for acupuncture from baseline (mean score, 23.5 [95% CI, 21.8 to 25.2]) to week 4 (mean score, 15.3 [CI, 13.6 to 16.9]) was -8.2 (CI, -9.9 to -6.6). The mean changes in UAS7 for sham acupuncture and waitlist control from baseline (mean scores, 21.9 [CI, 20.2 to 23.6] and 22.1 [CI, 20.4 to 23.8], respectively) to week 4 (mean scores, 17.8 [CI, 16.1 to 19.5] and 20.0 [CI, 18.3 to 21.6], respectively) were -4.1 (CI, -5.8 to -2.4) and -2.2 (CI, -3.8 to -0.5), respectively. The mean differences between acupuncture and sham acupuncture and waitlist control were -4.1 (CI, -6.5 to -1.8) and -6.1 (CI, -8.4 to -3.7), respectively, which did not meet the threshold for minimal clinically important difference. Fifteen participants (13.6%) in the acupuncture group and none in the other groups reported adverse events. Adverse events were mild or transient.

LIMITATION

Lack of complete blinding, self-reported outcomes, limited generalizability because antihistamine use was disallowed, and short follow-up period.

CONCLUSION

Compared with sham acupuncture and waitlist control, acupuncture produced a greater improvement in UAS7, although the difference from control was not clinically significant. Increased adverse events were mild or transient.

PRIMARY FUNDING SOURCE

The National Key R&D Program of China and the Science and Technology Department of Sichuan Province.

Role of GRPR in Acupuncture Intervention in the "Itch-scratch Vicious Cycle" Spinal Circuit of Chronic Pruritus

Many previous studies have shown the potential antipruritic effect of acupuncture. This paper reviews the antipruritic mechanisms of acupuncture according to these aspects: sample characteristics, detail of intervention, and effects evaluation. The majority of research on acupuncture's antipruritic effect has focused on primary afferents of the peripheral mechanism. Relatively few studies, however, have addressed the central mechanisms. Combination the latest research achievements of chronic itch, gastrin-releasing peptide receptor (GRPR) in the dorsal horn of the spinal cord may represent the first molecule identified that is dedicated to mediating the itch response and may provide an important therapeutic target for the treatment of chronic pruritic conditions. Therefore, GRPR may be a new target for acupuncture to relieve itch in the future and provide new ideas for acupuncture intervention in the mechanisms of the spinal level of the "itch-scratch vicious cycle" of chronic itch.

Pruritus in Chronic Kidney Disease: An Update

Chronic kidney disease-associated pruritus (CKDaP) is an often under-diagnosed and under-recognized condition, despite its considerable prevalence within the chronic kidney disease (CKD) population. Universally accepted guidelines are also lacking. The true prevalence of CKDaP worldwide therefore remains unknown, although its negative impact on mortality and health-related quality of life outcomes is very clear. The pathophysiological mechanisms leading to the onset of CKDaP are only partly understood. CKDaP is currently believed to be caused by a multifactorial process, from local skin changes, metabolic alterations, the development of neuropathy and dysregulation of opioid pathways, and psychological factors. Much work has been carried out towards a more systematic and structured approach to clinical diagnosis. Various tools are now available to assess the severity of CKDaP. Many of these tools require greater validation before they can be incorporated into the guidelines and into routine clinical practice. Further efforts are also needed in order to increase the awareness of clinicians and patients so that they can identify the CKDaP signs and symptoms in a timely manner. Currently established treatment options for CKDaP focus on the prevention of xerosis via topical emollients, the optimization of dialysis management, early referral to kidney transplantation if appropriate, oral antihistamine, and a variety of neuropathic agents. Other novel treatment options include the following: topical analgesics, topical tacrolimus, cannabinoid-containing compounds, antidepressants, oral leukotrienes, opioids, and non-pharmacological alternative therapies (i.e., phototherapy, dietary supplements, acupuncture/acupressure). We provide an updated review on the evidence relating to the epidemiology, the pathophysiology, the clinical assessment and diagnosis, and the management of CKDaP.

Treatment Options for Troublesome Itch

Itch (or pruritus) is an unpleasant sensation, inducing the desire to scratch. It is also a major and distressing symptom of many skin and systemic diseases. The involvement of histamine, which is a major itch mediator, has been extensively examined. Recent studies suggest that histamine-independent pathways may play roles in chronic itch. Therefore, antihistamines are not always effective in the treatment of patients with chronic itch. The development of biologics and κ-opioid receptor (KOR) agonists has contributed to advances in the treatment of itch; however, since biologics are expensive for patients to purchase, some patients may limit or discontinue their use of these agents. Furthermore, KOR agonists need to be prescribed with caution due to risks of side effects in the central nervous system. Janus kinase (JAK) inhibitors are sometimes associated with side effects, such as infection. In this review, we summarize antidepressants, antineuralgics, cyclosporine A, antibiotics, crotamiton, phosphodiesterase 4 inhibitor, botulinum toxin type A, herbal medicines, phototherapy, and acupuncture therapy as itch treatment options other than antihistamines, biologics, opioids, and JAK inhibitors; we also explain their underlying mechanisms of action.

Acupuncture mechanism studies employing task-based fMRI: a scoping review protocol

BACKGROUND

Acupuncture is a widely used alternative and complementary therapy. Functional magnetic resonance imaging (fMRI) is an important technique to explore the underlying mechanism of acupuncture, and the task-based fMRI can reflect the instant effects or sustained effects of acupuncture in the brain. This scoping review aims to summarize the characteristics of acupuncture mechanism studies employing task-based fMRI and conclude a reference for future studies.

METHODS/DESIGN

This review will follow the Guidance for Conducting Scoping Reviews. Eligible articles will be collected from 7 databases (PubMed, Embase, Cochrane, CNKI, WanFang, VIP, and CBM) with the related keywords such as "Acupuncture" and "fMRI"; those articles should be published from January 1, 2000, to December 31, 2021; and the language should be restricted in English or Chinese. Each research step will involve at least two reviewers. The PRISMA-ScR (Preferred Reporting Items for Systemic Reviews and Meta-Analysis Extension for Scoping Reviews) will be used to organize the review. Data will be extracted from the illegible articles, and findings will be presented in tables and narrative form. A descriptive qualitative approach to analysis will be conducted to form the scoping review.

DISCUSSION

This review aims to clarify the extent of acupuncture mechanism studies employing task-based fMRI. It is supposed to make a critical evaluation or propose quality requirements for future studies by summarizing the objectives and designs of eligible studies. What is more, directional suggestions will be provided for further studies.

SCOPING REVIEW REGISTRATION

Open Science Framework https://osf.io/zjrdc/ .

Acupuncture for the Treatment of Itch: Peripheral and Central Mechanisms

Despite the widespread clinical use of acupuncture in the treatment of pruritus caused by psoriasis, urticaria, uremic, and other diseases, insights into the mechanism of action of acupuncture are still emerging. For the above reasons, a beneficial effect of acupuncture on pruritus was not recommended or reported in recent clinical practice guidelines. Acupuncture is a kind of physical stimulation, which has the characteristics of multi-channel and multi-target effects. The biomechanical stimulation signal of acupuncture needling can be transformed into bioelectric and chemical signals; interfere with kinds of cells and nerve fibers in the skin and muscle; alter signaling pathways and transcriptional activity of cells, mediators, and receptors; and result in inhibition of peripheral and central transmission of pruritus. Available mechanistic data give insights into the biological regulation potency of acupuncture for pruritus and provide a basis for more in-depth and comprehensive mechanism research.

Mild Skin Heating Evokes Warmth Hyperknesis Selectively for Histaminergic and Serotoninergic Itch in Humans

Chronic itch can severely affect quality of life. Patients report that their chronic itch can be exacerbated by exposure to warm conditions (“warmth hyperknesis”). The aim of this mechanistic study was to investigate the effect of mild heating of the skin in humans on various experimental models of itch. A total of 18 healthy subjects were recruited to the study. Itch was provoked by histamine, serotonin, or cowhage in 3 different sessions. The provoked area was heated with an infrared lamp, and the skin temperature was either not altered, or was increased by 4°C or 7°C. Subsequent to induction of itch, the itch intensity was recorded for 10 min while the skin was heated continuously throughout the entire period of itch induction. Heating the skin resulted in a significant increase in itch intensity when provoked by histamine or serotonin. It is possible that thermoception and pruriception interact and selectively produce a higher itch intensity in histaminergic and serotoninergic itch.

Clinical management of chronic kidney disease-associated pruritus: current treatment options and future approaches

Chronic kidney disease (CKD)-associated pruritus (CKD-aP) is an underdiagnosed yet severely distressing condition that impacts 60% of patients on dialysis and many nondialysis patients with Stages 3–5 CKD. However, despite its high prevalence, there are currently limited treatment options available for these patients and a lack of treatment guidelines for clinicians. In this manuscript, we reviewed the available literature in order to evaluate the current management and treatment options for CKD-aP, including dialysis management, topical treatments, gabapentinoids, opioids and alternative medicine. We also review the available data on CKD-aP treatments in development and propose new guidelines for managing patients with CKD-aP.

Effect of acupuncture treatment in patients with mild to moderate atopic dermatitis: a randomized, participant- and assessor-blind sham-controlled trial

BACKGROUND

Atopic dermatitis (AD) is a chronic recurrent inflammatory skin disease that affects 1-3% of adults worldwide. Currently, it is not possible to completely cure AD; therefore, alternative treatments need to be developed to meet the patients' needs. Here, based on our previous pilot study, we conducted the first confirmatory randomized controlled trial to evaluate the effect of acupuncture in patients with mild to moderate AD.

METHODS

A randomized, participant- and assessor-blinded, sham-controlled trial was designed with an intervention period twice-weekly for 4 weeks and a 4-week follow-up. We equally allocated 36 participants to the verum acupuncture (VA) and sham acupuncture (SA) groups. The main outcome measure was the change in SCORing Atopic Dermatitis index (SCORAD) score before and after treatment.

RESULTS

A total of 36 participants, aged 19 to 38 years, were enrolled, and 35 were included in the intention-to-treat analyses. The mean change in total SCORAD score differed significantly among the two groups at 4 weeks after randomization (P < .0001): the mean difference was - 11.83 (7.05) in the VA group and 0.45 (7.77) in the SA group. The mean SCORAD score substantially decreased 2-weeks after starting the acupuncture treatment and continued to improve for at least 4 weeks after the end of the treatment in the VA group compared to the SA group (each P < .0001). No serious adverse events were observed.

CONCLUSIONS

Twice-weekly acupuncture treatment was effective in reducing AD symptoms in patients with mild to moderate AD without serious adverse events.

TRIAL REGISTRATION

Clinical Research Information Service Identifier: KCT0002796 .

Acupuncture ameliorates not only atopic dermatitis-like skin inflammation but also acute and chronic serotonergic itch possibly through blockade of 5-HT2 and 5-HT7 receptors in mice

Acupuncture has been known to be effective for atopic dermatitis, especially ameliorating itch; however, its mechanisms are still unclear. The aim of this study was to test the anti-itch effects of acupuncture and to investigate its possible mechanisms. Acupuncture was performed at Gok-Ji (LI11) acupoints just before the injection of pruritogens in the mouse cheek model of acute itch and of MC903-induced atopic dermatitis displaying serotonergic chronic itch. Acupuncture significantly reduced acute itch triggered by compound 48/80, chloroquine, or especially serotonin. It also markedly reduced scratching behaviors evoked by the serotonin 5-HT₂ receptor agonist α-methylserotonin and selective 5-HT₇ receptor agonist LP 44. In addition, acupuncture treatment at LI11 had the preventive and therapeutic effects on persistent itch as well as the robust skin inflammation with epidermal thickening in mice with MC903-induced atopic dermatitis. It also considerably reduced the increased expression of 5-HT_2A, 5-HT_2B and 5-HT₇ receptors in atopic dermatitis-like skin lesions in mice treated with MC903. Taken together, these findings highlight that acupuncture significantly ameliorates not only skin inflammation, but also acute and chronic serotonergic itch, possibly through blockade of serotonin 5-HT₂ and 5-HT₇ receptors.

Have We Just Scratched the Surface? A Narrative Review of Uremic Pruritus in 2020

Purpose of review:

Uremic pruritus is a highly prevalent and debilitating symptom in patients with chronic kidney disease (CKD) and end-stage kidney disease (ESKD). The purpose of this review is to examine current evidence on the mechanisms and treatments of pruritus in CKD and highlight promising areas for future research.

Sources of information:

Published literature, including randomized controlled trials, cohort studies, case reports, and review articles, was searched for evidence pertaining to the pathophysiology and treatment of uremic pruritus.

Methods:

A comprehensive narrative review was conducted to explore the molecular mechanisms underlying uremic pruritus, as well as the evidence (or lack thereof) supporting pharmacological and nonpharmacological treatments for uremic pruritus. The potential role of patient sex in the pathophysiology and management of uremic pruritus is also discussed.

Key findings:

The pathophysiology of uremic pruritus involves a complex interplay of uremic toxins, systemic inflammation, mast cell activation, and imbalance of opioid receptors. Classic treatment strategies for uremic pruritus include optimization of dialysis parameters, amelioration of CKD-related mineral and bone disease, topical emollients and analgesics, antihistamines, the anticonvulsant medications gabapentin and pregabalin, and ultraviolet light B (UV-B) phototherapy. Strong data to support many of these classical treatments for uremic pruritus are limited. Newly evolving treatment approaches for uremic pruritus include opioid receptor modulators, neurokinin-1 inhibitors, and cannabinoids. Further studies regarding their efficacy, pharmacodynamics, and safety in the CKD and ESKD population are needed before these agents are accepted into widespread use. Additional nonpharmacological strategies aimed at treating uremic pruritus include psychotherapy, acupuncture, omega-3 fatty acids, and exercise. Finally, sex differences may exist regarding uremic pruritus, but studies directly addressing sex-specific mechanisms of uremic pruritus remain absent.

Limitations:

High-quality evidence in the management of uremic pruritus remains lacking. Most recommendations are based on expert opinion or studies involving small numbers of patients. In addition, our understanding of the pathophysiological mechanisms behind uremic pruritus is incomplete and continues to evolve over time.

Implications:

Uremic pruritus is a common symptom which reduces quality of life in CKD and ESKD. The identification of novel targeted treatment approaches may ease the burden of uremic pruritus in the future.

Emerging Therapeutic Options for Chronic Pruritus

Chronic pruritus, defined as an unpleasant sensation resulting in a need to scratch that lasts more than 6 weeks, is a prevalent and bothersome symptom associated with both cutaneous and systemic conditions. Due to complex pathogenesis and profuse contributing factors, chronic pruritus therapy remains challenging. Regardless of the well-established antipruritic properties of classic pharmacotherapy (topical therapy, phototherapy and systemic therapy), these methods often provide insufficient relief for affected individuals. Owing to the growing interest in the field of pruritic research, further experimental and clinical data have emerged, continuously supporting the possibility of instigating novel therapeutic measures. This review covers the most relevant current modalities remaining under investigation that possess promising perspectives of approval in the near future, especially opioidergic drugs (mu-opioid antagonists and kappa-opioid agonists), neurokinin-1 receptor antagonists, biologic drugs, Janus kinase inhibitors, ileal bile acid transporter inhibitors, aryl hydrocarbon receptor agonists and histamine H₄ receptor antagonists.

Acupuncture for patients with chronic pruritus: protocol of a systematic review and meta-analysis

INTRODUCTION

Chronic pruritus (CP) frequently occurs in many skin and systemic diseases, and adversely affects quality of life. This systematic review aims to evaluate treatment effects of acupuncture on CP.

METHODS AND ANALYSIS

An electronic and manual search will be conducted for all acupuncture treatments for CP, from the inception date of predefined database up to 28 February 2020. Databases include PubMed, Embase, Springer, Web of Science, the Cochrane Library, the World Health Organization International Clinical Trial Registration Platform, the Chinese Medicine Database, the China National Knowledge Infrastructure, the Chinese Biomedical Literature Database, the China Science Journal Database and the Wanfang Database. Other sources, including existing systematic reviews, conference proceedings and reference lists of identified publications will also be searched. Additionally, any clinical randomised controlled trials related to acupuncture treatment for CP, regardless of the publication status and language limitations, will be included. Study selection, data extraction and research quality assessments will be conducted independently by two researchers. The primary outcome measures include the Visual Analogue Scale, Urdu 5D-Itch Scale or other validated scales implemented after at least 2 weeks of treatment. Secondary outcomes include the effective rate, Quality of Life Scale (eg, the EQ-5D third level, the Dermatology Life Quality Index, etc.), Pittsburgh Sleep Quality Index, recurrence rate during the follow-up period and adverse events. If possible, meta-analyses will be performed using RevMan V.5.3 statistical software; otherwise, a descriptive analysis or subgroup analysis will be conducted. The results will be presented as the risk ratio of the binary data and the mean difference (MD) or standardised MD of the continuous data.

ETHICS AND DISSEMINATION

This systematic review protocol does not require formal ethical approval because the data are not personalised. It will be published in peer-reviewed journals and presented at international academic conferences.

PROSPERO REGISTRATION NUMBER

CRD42019136727.

Spatial Information of Somatosensory Stimuli in the Brain: Multivariate Pattern Analysis of Functional Magnetic Resonance Imaging Data

Background

Multivoxel pattern analysis has provided new evidence on somatotopic representation in the human brain. However, the effects of stimulus modality (e.g., penetrating needle versus non-penetrating touch) and level of classification (e.g., multiclass versus binary classification) on patterns of brain activity encoding spatial information of body parts have not yet been studied. We hypothesized that performance of brain-based prediction models may vary across the types of stimuli, and neural patterns of voxels in the SI and parietal cortex would significantly contribute to the prediction of stimulated locations.

Objective

We aimed to (1) test whether brain responses to tactile stimuli could distinguish among stimulated locations on the body surface, (2) investigate whether the stimulus modality and number of classes affect classification performance, and (3) localize brain regions encoding the spatial information of somatosensory stimuli.

Methods

Fifteen healthy participants completed two functional magnetic resonance imaging (MRI) scans and were stimulated via the insertion of acupuncture needles or by non-invasive touch stimuli (5.46-sized von Frey filament). Participants received the stimuli at four different locations on the upper and lower limbs (two sites each) for 5 min while blood-oxygen-level-dependent activity (BOLD) was measured using 3-Tesla MRI. We performed multivariate pattern analysis (MVPA) using parameter estimate images of each trial for each participant and the support vector classifier (SVC) function, and the prediction accuracy and other MVPA outcomes were evaluated using stratified five-fold cross validation. We estimated the significance of the classification accuracy using a permutation test with randomly labeled training data (n = 10,000). Searchlight analysis was conducted to identify brain regions associated with significantly higher accuracy compared to predictions based on chance as obtained from a random classifier.

Results

For the four-class classification (classifying four stimulated points on the body), SVC analysis of whole-brain beta values in response to acupuncture stimulation was able to discriminate among stimulated locations (mean accuracy, 0.31; q < 0.01). The searchlight analysis found that values related to the right primary somatosensory cortex (SI) and intraparietal sulcus were significantly more accurate than those due to chance (p < 0.01). On the other hand, the same classifier did not predict stimulated locations accurately for touch stimulation (mean accuracy, 0.25; q = 0.66). For binary classification (discriminating between two stimulated body parts, i.e., the arm or leg), the SVC algorithm successfully predicted the stimulated body parts for both acupuncture (mean accuracy, 0.63; q < 0.001) and touch stimulation (mean accuracy, 0.60; q < 0.01). Searchlight analysis revealed that predictions based on the right SI, primary motor cortex (MI), paracentral gyrus, and superior frontal gyrus were significantly more accurate compared to predictions based on chance (p < 0.05).

Conclusion

Our findings suggest that the SI, as well as the MI, intraparietal sulcus, paracentral gyrus, and superior frontal gyrus, is responsible for the somatotopic representation of body parts stimulated by tactile stimuli. The MVPA approach for identifying neural patterns encoding spatial information of somatosensory stimuli may be affected by the stimulus type (penetrating needle versus non-invasive touch) and the number of classes (classification of four small points on the body versus two large body parts). Future studies with larger samples will identify stimulus-specific neural patterns representing stimulated locations, independent of subjective tactile perception and emotional responses. Identification of distinct neural patterns of body surfaces will help in improving neural biomarkers for pain and other sensory percepts in the future.