Itch and Mental Health in Dermatological Patients across Europe: A Cross-Sectional Study in 13 Countries

Symptom severity reflected by NYHA grade is independently associated with pruritus in chronic heart failure patients

BACKGROUND

Pruritus is a symptom profoundly impairing patients' quality of life (QoL). It is a common symptom in chronic heart failure (CHF) patients of yet unknown nature. The aim of this study was to evaluate the risk factors of pruritus in CHF patients.

METHODS

For this monocentric, prospective cohort study, CHF patients were recruited and CHF symptoms, comorbidities and drug intake were assessed using a structured report. Additionally, a questionnaire evaluated pruritus symptoms. Detailed medical histories including laboratory test results were retrieved from patient files for all participants.

RESULTS

We evaluated data from 550 CHF patients. Of those, 25.3% reported pruritus to occur frequently (3-5 times per week), often (1-2 times per week) or daily. Patients of higher NYHA classes (NYHA III + IV) experienced significantly more pruritus (31.2%) than lower NYHA classes (NYHA I + II) (21.1%, p = 0.024). Patients with pruritus reported disproportionately often concomitant stasis dermatitis (p = 0.026) and chronic lung disease (p = 0.014). Other parameters reflecting cardiac, liver, kidney and thyroid function, as well as medical therapies showed no significant differences between patients with and without pruritus. In the multivariate logistic regression analysis, only NYHA class (p = 0.016, OR 1.55, 95% confidence interval (CI): [1.09; 2.20]) and elevated leukocyte count (p = 0.007, OR 1.11, CI [1.03; 1.21]) remained significantly associated with pruritus in CHF patients.

CONCLUSIONS

NYHA class is an independent predictor for pruritus in CHF patients. Besides NYHA class, leukocyte count was also associated with increased pruritus. Pruritus may impair QoL in CHF patients and should thus be included in the assessment of those patients. We suggest that providing best care for CHF patients can be achieved through an interdisciplinary approach of cardiologists and dermatologists and should include a pruritus assessment.

Validation of the German Pruritus Questionnaire for the systematic assessment of chronic pruritus

BACKGROUND

Chronic pruritus is a clinically heterogeneous symptom that manifests itself with varying duration, intensity, or quality. To date, there is no validated German-language instrument that systematically assesses the relevant parameters. With the support of the Pruritus Research Working Group (Arbeitsgemeinschaft Pruritusforschung, AGP), a questionnaire for the assessment of chronic pruritus (AGP questionnaire) was developed in 2008. The subsequently revised instrument, now called the German Pruritus Questionnaire, records pruritus-specific parameters such as localization, course, intensity and quality, anamnestic data on the general state of health, sociodemographic data, quality of life, and coping methods. It is to be validated in the study presented here.

PATIENTS AND METHODS

The questionnaire was used in 366 patients with chronic pruritus of different etiologies from Germany (University Hospitals Heidelberg, Münster, Mainz, Erlangen, Giessen, private practice Bad Bentheim, TU Munich, Wiesbaden Kidney Center), Austria (Graz University Hospital) and Switzerland (Aarau Cantonal Hospital).

RESULTS

The reliability for repeated completion (retest reliability) with regard to localization, first occurrence, and concomitant diseases showed high values for Cohen's kappa (> 0.8). The data on the retest reliability of the pruritus characteristics showed lower values (< 0.7). With regard to the measurability of practically relevant changes (change sensitivity), medium to strong effect sizes were found (0.09-0.19). A statistically significant differentiation of the pruritus etiologies based on the recorded parameters was not possible.

CONCLUSIONS

The German Pruritus Questionnaire allows a comprehensive and structured recording of patient- and clinician-reported, relevant dimensions of chronic pruritus of different etiologies. Further adaptation and development are planned.

Chronic Pruritus: A Review

Importance

Chronic pruritus, defined as itch experienced for 6 weeks or longer, affects approximately 22% of people in their lifetime. Approximately 1% of physician visits are for the chief concern of chronic pruritus. Chronic pruritus is associated with adverse outcomes, including impaired sleep and reduced quality of life.

Observations

Chronic pruritus can be categorized by etiology into inflammatory, neuropathic, or a combination of inflammatory and neuropathic pruritus. Chronic pruritus is due to inflammation in approximately 60% of patients and may be caused by eczema, psoriasis, or seborrheic dermatitis. Chronic pruritus is due to a neuropathic or mixed etiology in approximately 25% of patients. Neuropathic causes of chronic pruritus include postherpetic neuralgia and notalgia paresthetica and are typically due to localized or generalized nerve dysregulation. Approximately 15% of people with chronic pruritus have other causes including systemic diseases with secondary itch, such as uremic pruritus and cholestatic pruritus, medication-induced pruritus such as pruritus due to immunotherapy, and infectious etiologies such as tinea corporis and scabies. When few primary changes are present, a thorough history, review of symptoms, and laboratory evaluation should be performed, particularly for people with chronic pruritus lasting less than 1 year. Clinicians should consider the following tests: complete blood cell count, complete metabolic panel, and thyroid function testing to evaluate for hematologic malignancy, liver disease, kidney disease, or thyroid disease. First-line treatment for inflammatory chronic pruritus includes topical anti-inflammatory therapies such as hydrocortisone (2.5%), triamcinolone (0.1%), or tacrolimus ointment. Approximately 10% of patients do not respond to topical therapies. In these patients, referral to dermatology and systemic oral or injectable treatments such as dupilumab or methotrexate may be considered. When no underlying systemic disease associated with pruritus is identified, patients are likely to have neuropathic chronic pruritus or mixed etiology such as chronic pruritus of unknown origin. In these patients, neuropathic topical treatments such as menthol, pramoxine, or lidocaine can be used either alone or in combination with immunomodulatory agents such as topical steroids. Other effective therapies for neuropathic pruritus include gabapentin, antidepressants such as sertraline or doxepin, or opioid receptor agonist/antagonists such as naltrexone or butorphanol.

Conclusions and Relevance

Chronic pruritus can adversely affect quality of life and can be categorized into inflammatory, neuropathic, or a combined etiology. First-line therapies are topical steroids for inflammatory causes, such as hydrocortisone (2.5%) or triamcinolone (0.1%); topical neuropathic agents for neuropathic causes, such as menthol or pramoxine; and combinations of these therapies for mixed etiologies of chronic pruritus.

Global Prevalence of Anxiety, Depression, and Stress Among Patients with Skin Diseases: A Systematic Review and Meta-analysis

The changes in human lifestyle over the past few decades have impacted the prevalence of skin diseases within different societies. Skin diseases may result in various physical and mental disorders. The most common mental disorders observed among the patients are stress, anxiety, and depression. This study aims to investigate the global prevalence of anxiety, depression, and stress in patients with skin diseases. In this Systematic Review and Meta-Analysis study, the PubMed, Scopus, Science Direct, Embase, Web of science, and Google Scholar repositories were searched without a lower time limit. Heterogeneity among the identified studies was examined using the I2 index, and accordingly random effects model was adopted for analysis. Data analysis was conducted within the Comprehensive Meta-Analysis software (v. 2). In total, 113 studies were included for the final analysis. The overall pooled prevalence of stress, depression, and anxiety in skin disease patients was found to be 39.4%, 27.2% and 28.8%, respectively. Among patients with psoriasis, acne, vitiligo or atopic dermatitis diseases, the highest number of patients suffering from stress was related to patients with acne (75.7%). The highest prevalence of depression, and anxiety was reported in patients with vitiligo (38.3%) and acne (36.5%), respectively. Considering the high prevalence of mental disorders among patients with skin diseases and recognising the impacts of mental health challenges on patients' well-being, the findings of this study provide valuable insights for identifying specific populations that require targeted interventions for the diagnosis, treatment, and prevention of mental illnesses. Accordingly, healthcare policymakers should incorporate psychological treatment and support measures as integral components of comprehensive care strategies for patients with skin diseases.

Genetic analyses unravel the causal association of cytokine levels on lichen simplex chronicus risk: insights from a mendelian randomization study

Lichen simplex chronicus (LSC) presents a challenge in dermatology due to its elusive pathogenic mechanisms. While associations between circulating inflammatory cytokines and LSC were observed, the definitive causal dynamics remain to be elucidated. Our study used a two-sample Mendelian randomization (MR) approach to investigate causal relationships. We applied a suite of MR methodologies, including IVW, Weighted Median, MR-Egger, Weighted Mode, Simple Mode, MR-PRESSO, and the Steiger test, to ensure robust causal inference. Our analysis confirmed the causal impact of genetically determined cytokine levels on LSC risk, particularly MMP-10 (OR = 0.493, P = 0.004) and DNER (OR = 0.651, P = 0.043) in risk attenuation. We also found a positive causal correlation between GDNF levels (OR = 1.871, P = 0.007) and LSC prevalence. Notably, bidirectional causality was observed between DNER and LSC. Consistency across various MR analyses and sensitivity analyses confirmed the absence of horizontal pleiotropy, validating the causal estimates. This pioneering MR investigation unveils a novel genetically anchored causal relationship between the circulating levels of MMP-10, DNER, and GDNF and LSC risk. Although further validation is requisite, our findings augment the understanding of cytokine mediation in LSC and underscore prospective avenues for research.

An insular cortical circuit required for itch sensation and aversion

Itch encompasses both sensory and emotional dimensions, with the two dimensions reciprocally exacerbating each other. However, whether a shared neural circuit mechanism governs both dimensions remains elusive. Here, we report that the anterior insular cortex (AIC) is activated by both histamine-dependent and -independent itch stimuli. The activation of AIC elicits aversive emotion and exacerbates pruritogen-induced itch sensation and aversion. Mechanistically, AIC excitatory neurons project to the GABAergic neurons in the dorsal bed nucleus of the stria terminalis (dBNST). Manipulating the activity of the AIC → dBNST pathway affects both itch sensation and itch-induced aversion. Our study discovers the shared neural circuit (AIC → dBNST pathway) underlying the itch sensation and aversion, highlights the critical role of the AIC as a central hub for the itch processing, and provides a framework to understand the neural mechanisms underlying the sensation and emotion interaction.

Dermatological patients with itch report more stress, stigmatization experience, anxiety and depression compared to patients without itch: Results from a European multi-centre study

BACKGROUND

Itch as the most common symptom in dermatology has been shown to be related to psychological factors such as stress, anxiety and depression. Moreover, associations were found between perceived stigmatization and itch. However, studies investigating the differences between patients with dermatoses with and without itch regarding perceived stress, stigmatization, anxiety and depression are missing. Therefore, one of the aims of the second study of the European Society for Dermatology and Psychiatry (ESDaP study II) was to investigate these relationships in a large cohort of patients with different itchy dermatoses.

RESULTS

3399 patients with 14 different itchy dermatoses were recruited at 22 centres in 17 European countries. They filled in questionnaires to assess perceived stigmatization, stress, signs of clinically relevant anxiety or depression, itch-related quality of life, the overall health status, itch duration, frequency and intensity. The most significant association between the severity of itching and the perception of stress was observed among individuals with rosacea (correlation coefficient r = 0.314). Similarly, the strongest links between itch intensity and experiences of stigmatization, anxiety, and depression were found in patients with seborrheic dermatitis (correlation coefficients r = 0.317, r = 0.356, and r = 0.400, respectively). Utilizing a stepwise linear regression analysis, it was determined that within the entire patient cohort, 9.3% of the variation in itch intensity could be accounted for by factors including gender, levels of anxiety, depression, and perceived stigmatization. Females and individuals with elevated anxiety, depression, and perceived stigmatization scores reported more pronounced itch intensities compared to those with contrary attributes.

CONCLUSION

This study underscores the connection between experiencing itch and its intensity and the psychological strain it places on individuals. Consequently, psychological interventions should encompass both addressing the itch itself and the interconnected psychological factors. In specific cases, it becomes imperative for dermatologists to direct individuals towards suitable healthcare resources to undergo further psychological assessment.

Epidemiology of mental health comorbidity in patients with atopic dermatitis: An analysis of global trends from 1998 to 2022

The prevalence rates of attention deficit hyperactivity disorder (ADHD), depression, anxiety and suicide are increasing in patients with atopic dermatitis (AD), although no research has systematically examined these trends yet. Here, we explore the prevalence of the occurrence of comorbidities, such as ADHD, depression, anxiety and suicide with AD. We searched seven electronic databases from inception to October 2022 to identify relevant studies, and the Agency for Healthcare Research and Quality (AHRQ) and Newcastle-Ottawa Scale (NOS) tools were used to assess the quality of observational studies. Statistical analysis was performed using R software. Publication bias was evaluated using Egger's and Begg's linear tests. The global prevalence rates of ADHD, depression, anxiety and suicidal ideation in patients with AD were 7%, 17%, 21% and 13%, respectively, between 1998 and October 2022. Among children (aged <18 years), North American children with AD had the highest prevalence rates of ADHD (10%), depression (13%) and anxiety (20%). Among the adult (aged ≥18 years) population, patients with AD in Africa had the highest prevalence rates of depression (36%) and anxiety (44%), while Asian adults with AD had the highest prevalence rates of ADHD (7%) and suicidal ideation (20%). These results highlight the high prevalence and comorbidity rates of mental illnesses with AD, which should be brought to the attention of patients with AD and their physicians.

Pruritus is associated with longer hospital stays and higher costs in psychiatric inpatients from the USA National Inpatient Sample (2012-2015): a cross-sectional study

This national inpatient data analysis determined that, in addition to the increased costs and duration of hospital stay associated with pruritus, the prevalence of pruritus during inpatient psychiatric admissions in the USA is 18.6% (approximately 1 in 5 patients).

Measuring the impact of pruritus in patients with epidermolysis bullosa: evaluation with an itch-specific instrument

Pruritus is one of the most debilitating symptoms for patients with epidermolysis bullosa (EB). This study aimed to assess the burden of itch and to address its dimensions across patients with EB. Forty-six patients with EB were recruited from the Saudi EB registry to participate. All participants completed the Leuven Itch Scale. The sample included 5 patients with EB simplex (EBS), 3 with junctional EB (JEB), 34 with dystrophic EB (DEB), and 4 patients had unknown type. Overall, 97.8% patients reported itch. In patients with itch, 73.3% reported that it was often or always present, longer than 2h Itch episodes was reported by JEB (66.7%) and recessive DEB (3.2%). Itch, in all its dimensions, was worst in patients with JEB and DEB than EBS. Itch occurred mostly in a hot environment (80%), when sweating (71.1%), in healing wounds (40%), and during dressing change (35.6%) whereas cold environment resulted in itch in only (2.2%). The burden of pruritus increased with increasing age. This study highlights a challenging area in EB care with a need for specific treatments.

Mental health comorbidity in youth with atopic dermatitis: A narrative review of possible mechanisms

The presence of atopic dermatitis (AD) in youth has been linked to a variety of mental health concerns including disruptive behavior, symptoms of anxiety and depression, and diagnoses of attention deficit/hyperactivity disorder and autism spectrum disorder. However, the factors accounting for these relationships are not well understood. The current review summarizes possible mechanisms identified in previous research and highlights areas for future investigation. Among the primary mechanisms studied to date, child sleep is the only factor that has been characterized in relative detail, with findings generally supporting the mediating role of sleep problems in the relationship between AD and psychological symptoms. There is substantial evidence suggesting a negative impact of child AD on parent mental health and the impact of parent mental health on child psychological functioning, although the latter has not been assessed specifically in populations of children with AD. There is also preliminary support for other mechanisms, including pruritus and pain, atopic comorbidities, social functioning, and systemic antihistamine use, in the development of mental health concerns in pediatric AD. Furthermore, research suggests the presence of bidirectional relationships between AD and psychological functioning via inflammatory responses to stress and impaired treatment adherence. Overall, significant additional research is needed to better characterize the nature and magnitude of the relationships among these multiple mechanisms and various psychosocial outcomes. Nevertheless, the findings to date support routine screening of psychological health in patients with AD as well as screening for potential risk factors, which may also serve as targets of therapeutic intervention.

Berry Extracts and Their Bioactive Compounds Mitigate LPS and DNFB-Mediated Dendritic Cell Activation and Induction of Antigen Specific T-Cell Effector Responses

Berries have gained widespread recognition for their abundant natural antioxidant, anti-inflammatory, and immunomodulatory properties. However, there has been limited research conducted thus far to investigate the role of the active constituents of berries in alleviating contact hypersensitivity (CHS), the most prevalent occupational dermatological disease. Our study involved an ex vivo investigation aimed at evaluating the impact of black raspberry extract (BRB-E) and various natural compounds found in berries, such as protocatechuic acid (PCA), proanthocyanidins (PANT), ellagic acid (EA), and kaempferol (KMP), on mitigating the pathogenicity of CHS. We examined the efficacy of these natural compounds on the activation of dendritic cells (DCs) triggered by 2,4-dinitrofluorobenzene (DNFB) and lipopolysaccharide (LPS). Specifically, we measured the expression of activation markers CD40, CD80, CD83, and CD86 and the production of proinflammatory cytokines, including Interleukin (IL)-12, IL-6, TNF-α, and IL-10, to gain further insights. Potential mechanisms through which these phytochemicals could alleviate CHS were also investigated by investigating the role of phospho-ERK. Subsequently, DCs were co-cultured with T-cells specific to the OVA323-339 peptide to examine the specific T-cell effector responses resulting from these interactions. Our findings demonstrated that BRB-E, PCA, PANT, and EA, but not KMP, inhibited phosphorylation of ERK in LPS-activated DCs. At higher doses, EA significantly reduced expression of all the activation markers studied in DNFB- and LPS-stimulated DCs. All compounds tested reduced the level of IL-6 in DNFB-stimulated DCs in Flt3L as well as in GM-CSF-derived DCs. However, levels of IL-12 were reduced by all the tested compounds in LPS-stimulated Flt3L-derived BMDCs. PCA, PANT, EA, and KMP inhibited the activated DC-mediated Interferon (IFN)-γ and IL-17 production by T-cells. Interestingly, PANT, EA, and KMP significantly reduced T-cell proliferation and the associated IL-2 production. Our study provides evidence for differential effects of berry extracts and natural compounds on DNFB and LPS-activated DCs revealing potential novel approaches for mitigating CHS.

Psychopathology Associated with Chronic Pruritus: A Systematic Review

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.

Prevalence of Chronic Pruritus in Elderly Black and White Inpatients: A Comparative Population Study

BACKGROUND

Black and geriatric patients were reported in small scale studies to have more intense chronic pruritus (CP). Studies comparing itch across geriatric racial groups are lacking.

OBJECTIVES

To compare the prevalence of CP in Black and White inpatients ≥ 65 years old as well as the top primary diagnoses of these populations.

METHODS

We used data from the National Inpatient Sample from 2016-2019 to analyze CP prevalence and ICD10-CM to identify diseases. The top five primary diagnoses were calculated for a subpopulation with CP. Sample characteristics were described, and the data was pooled and analyzed using IBM SPSS® Complex Sample modules.

RESULTS

Among hospitalized Black inpatients ≥ 65 years old, the prevalence of CP was 0.26% while in the White cohort it was 0.22%. The top five primary diagnoses in the Black population with itch were sepsis (4.2%); hypertensive heart and chronic kidney disease (CKD) with heart failure (HF) and stage 1-4 CKD, or unspecified CKD (4.1%); acute kidney failure (4.0%); hypertensive heart and CKD with HF with stage 5 CKD, or end-stage renal disease (2.1%); and hypertensive heart disease with HF (1.7%). The top five primary diagnoses in the White population were sepsis (4.25%); acute kidney failure (3.0%); hypertensive heart and CKD with HF and stage 1-4 CKD, or unspecified CKD (2.5%); cellulitis of left lower limb (1.9%); and unilateral primary osteoarthritis, right knee (1.9%).

CONCLUSIONS

Geriatric hospitalized Black patients demonstrated a higher prevalence of chronic itch compared with the White cohort, which may be related to the higher prevalence of chronic kidney disease in different stages of severity in this population.

Prevalence, Intensity and Psychosocial Burden of Acne Itch: Two Different Cohorts Study

BACKGROUND

Chronic itch is a common symptom of inflammatory skin diseases. This study was undertaken to evaluate the presence and intensity of itching in two different cohorts of acne subjects. Additionally, the influence of itching on the psychosocial status of acne individuals was assessed.

METHODS

Consecutive acne patients seeking dermatological advice and university students diagnosed with acne during dermatological screening were considered. The clinical and psychological aspects of acne were assessed using a variety of instruments.

RESULTS

About 40% of acne subjects in both cohorts reported itching. The mean WI-NRS during the last 3 days in acne patients was 3.83 ± 2.31 points (mild itch) and was significantly more severe (p < 0.001) than in university students diagnosed with acne (2.09 ± 1.29 points). Itch intensity did not depend on the clinical severity of acne. In consecutive acne patients, itch intensity correlated with quality-of-life impairments (assessed using DLQI and CADI) and HADS scores. There was no correlation between itch intensity and stigmatization levels.

CONCLUSIONS

Itching seems to be a common phenomenon in acne sufferers. Acne itch significantly influences patients' well-being and should be considered in a holistic approach to acne patients.

Arsenic exposure and pruritus: Evidence from observational, interventional, and mendelian randomization studies

BACKGROUND

Pruritus is identified as an adverse drug reaction to arsenic trioxide, but the association of arsenic exposure with pruritus has not been investigated.

METHODS

A cross-sectional study was conducted in Shimen, China. A Mendelian randomization analysis was conducted to confirm the causal relationship between genetically predicted percentages of monomethylated arsenic (MMA%) and dimethylated arsenic (DMA%) in urine with chronic pruritus in UK Biobank. A case-control study was then conducted to determine the biomarker for pruritus. Arsenite-treated mice were used to confirm the biomarker, and von Frey test was used to induce scratching bouts. Last, a randomized, double-blind, placebo-controlled trial was conducted to test the efficacy of naloxone in arsenic-exposed patients with pruritus in Shimen.

RESULTS

Hair arsenic (μg/g) showed a dose-response relationship with the intensity of itch in 1079 participants, with odds ratios (OR) of 1.11 for moderate-to-severe itch (p = 0.012). The Mendelian randomization analysis confirmed the causal relationship, with ORs of 1.043 for MMA% (p = 0.029) and 0.904 for DMA% (p = 0.077) above versus under median. Serum β-endorphin was identified as a significant biomarker for the intensity of itch (p < 0.001). Consistently, treatment with arsenite upregulated the level of β-endorphin (p = 0.002) and induced scratching bouts (p < 0.001) in mice. The randomized controlled trial in 126 participants showed that treatment with sublingual naloxone significantly relieved the intensity of itch in arsenic-exposed participants in 2 weeks (β = -0.98, p = 0.04).

CONCLUSION

Arsenic exposure is associated with pruritus, and β-endorphin serves as a biomarker of pruritus. Naloxone relieves pruritus in patients with arseniasis.

Chronic pruritus: from pathophysiology to drug design

Pruritus, the most common symptom in dermatology, is an innate response capable of protecting skin against irritants. Nonetheless, when it lasts more than six weeks it is assumed to be a chronic pathology having a negative impact on people's lives. Chronic pruritus (CP) can occur in common and rare skin diseases, having a high prevalence in global population. The existing therapies are unable to counteract CP or are associated with adverse effects, so the development of effective treatments is a pressing issue. The pathophysiological mechanisms underlying CP are not yet completely dissected but, based on current knowledge, involve a wide range of receptors, namely neurokinin 1 receptor (NK1R), Janus kinase (JAK), and transient receptor potential (TRP) ion channels, especially transient receptor potential vanilloid 1 (TRPV1) and transient receptor potential ankyrin 1 (TRPA1). This review will address the relevance of these molecular targets for the treatment of CP and molecules capable of modulating these receptors that have already been studied clinically or have the potential to possibly alleviate this pathology. According to scientific and clinical literature, there is an increase in the expression of these molecular targets in the lesioned skin of patients experiencing CP when compared with non-lesioned skin, highlighting their importance for the development of potential efficacious drugs through the design of antagonists/inhibitors.

Efficacy and safety of Chinese herbal medicine in the treatment of chronic pruritus: A systematic review and meta-analysis of randomized controlled trials

Background: Chronic pruritus (CP) is a common and aggravating symptom associated with skin and systemic diseases. Although clinical reports suggest that Chinese herbal medicine (CHM) is safe and effective in Chronic pruritus treatment, evidence to prove it is lacking. Therefore, in this review, we evaluated the therapeutic effects and safety of Chinese herbal medicine for the treatment of Chronic pruritus. Methods: Nine databases were searched for relevant randomized controlled trials (RCTs) from the inception of the database to 20 April 2022. The randomized controlled trials that compared the treatment of Chinese herbal medicine or a combination of Chinese herbal medicine and conventional western medicine treatment (WM) with western medicine treatment intervention for patients with Chronic pruritus were selected. We evaluated the effects of treatment with Chinese herbal medicine on the degree of pruritus, the Dermatology Life Quality Index (DLQI) score, response rate, recurrence rate, and incidence of adverse events in patients with Chronic pruritus. The risk of bias in each trial was evaluated using the Cochrane Collaboration tool. The RevMan software (version 5.3) was used for performing meta-analyses to determine the comparative effects. Results: Twenty-four randomized controlled trials were included, compared with placebo, moderate-quality evidence from one study showed that Chinese herbal medicine was associated with reduced visual analogue scale (VAS) (MD: -2.08; 95% CI = -2.34 to -1.82). Compared with western medicine treatment, low-to moderate-quality evidence from 8 studies indicated that Chinese herbal medicine was associated with reduced visual analogue scale, 4 studies indicated that Chinese herbal medicine was associated with reduced Dermatology Life Quality Index (MD = -1.80, 95% CI = -2.98 to -.62), and 7 studies indicated that Chinese herbal medicine was associated with improved Effective rate (RR: 1.26; 95% CI = 1.19-1.34). Compared with combination of Chinese herbal medicine and western medicine treatment, 16 studies indicated that Chinese herbal medicine was associated with reduced visual analogue scale, 4 studies indicated that Chinese herbal medicine was associated with reduced Dermatology Life Quality Index (MD = -2.37, 95% CI = -2.61 to -2.13), and 13 studies indicated that Chinese herbal medicine was associated with improved Effective rate (RR: 1.28; 95% CI = 1.21-1.36). No significant difference in the occurrence of adverse events in using Chinese herbal medicine or western medicine treatment was reported. Conclusion: The efficacy of Chinese herbal medicine used with or without western medicine treatment was better than western medicine treatment in treating chronic pruritus. However, only a few good studies are available regarding Chronic pruritus, and thus, high-quality studies are necessary to validate the conclusions of this study.

Association between Pruritus and Psychosocial Well-being: A Population-based Study among 6,809 Subjects

Pruritus has an extensive impact on functional, social and psychosocial behaviour. The association between pruritus and psychological well-being has mostly been studied among selected patient groups, whereas population-based studies are lacking. The aim of this study was to determine the association between pruritus and insomnia, quality of life, depression and anxiety at the population level in the general population. A cross-sectional population-based study was conducted in 2012 to 2013. Study subjects (n = 6,809) belonging to the Northern Finland Birth Cohort 1966 Study participated in a large follow-up study at the age of 45-47 years. They completed an extensive health questionnaire including questions on pruritus and several previously validated questionnaires regarding symptoms of psychosocial well-being. Pruritus affected 19.9% of the study subjects weekly, being more common in women than in men (p < 0.001). A significant association was found between both localized and generalized pruritus and symptoms of insomnia, depression, anxiety and decreased quality of life. The association was seen even in those with mild psychological symptoms/insomnia, and it affected both sexes. The severity of psychological symptoms increased with increasing frequency of pruritus. In conclusion, pruritus has a multiple effect on psychosocial well-being. Physicians should consider possible psychosocial symptoms in patients with pruritus.

Study protocol: Neuro-inflammatory parameters as mediators of the relationship between social anxiety and itch intensity: A cross-sectional, controlled laboratory study in patients with psoriasis and healthy skin controls

INTRODUCTION

Psoriasis (PSO) is a disease that in the majority of patients is accompanied by itch, which imposes a great burden and positively relates to anxiety. Social anxiety, a facet of anxiety associated with social withdrawal, may be a predictor of itch intensity in this patient group. Moreover, anxiety is linked to the secretion of neuroendocrine and inflammatory parameters such as substance P (SP), interleukin (IL)-6 and IL-17, which are also related to itch. In this research project, we investigate first, whether there is a direct relationship between social anxiety and itch intensity in patients with PSO and second whether the secretion of SP, IL-6 and IL-17 in the skin mediates this relationship. Additionally, PSO-patients are compared to healthy skin controls regarding their level of social anxiety, itch intensity and the secretion of SP, IL-6 and IL-17.

METHODS AND ANALYSES

For study 1, we aim to recruit 250 psoriasis patients and 250 healthy skin controls who complete questionnaires to assess social anxiety, itch intensity and control variables (e.g. sociodemographic variables and severity of PSO). A linear hierarchic regression will be used to determine whether social anxiety significantly contributes to itch intensity. In study 2, we plan to apply the suction blister method to 128 patients and healthy skin controls recruited from study 1 to determine SP, IL-6 and IL-17 in tissue fluid extracted from the skin. A mediation analysis will be conducted using the SPSS-macro PROCESS to test whether the relationship between social anxiety and itch is mediated by SP, IL-6 and IL-17.

TRIAL REGISTRATION NUMBERS

DRKS00023621 (study 1) and DRKS00023622 (study 2).

[Relevance of demographic and psychological factors in pruritus]

BACKGROUND

Pruritus is a frequent phenomenon in patients in dermatology. The severity of pruritus often cannot be explained by the severity of the underlying disease or chronification processes alone. Especially then, demographic and psychological variables should also be considered as moderators of the intensity of pruritus.

PURPOSE

Are there associations between sex, age, emotional and cognitive factors and pruritus intensity in patients with chronic pruritus (CP) and skin-healthy control subjects?

MATERIAL AND METHODS

Recently published studies on the abovenamed moderators of pruritus were searched for in PubMed, collated and the results are summarized.

RESULTS

It was found that women reported a higher intensity of pruritus than men. In addition, negative emotions such as fear, disgust, and anger are positively associated with pruritus in patients with CP. There are also associations between cognitive factors, such as attention, catastrophizing, and pruritus.

CONCLUSION

The associations between both demographic and psychological factors and pruritus should be considered in the diagnostics and treatment of pruritus. A psychological intervention as a complementary treatment should be considered whenever patients report associations between psychological experiences and pruritus and/or automatic or extensive scratching.

Health-related quality of life in patients with neurofibromatosis 1 in Japan: A questionnaire survey using EQ-5D-5L

Neurofibromatosis 1 (NF1) is a genetic disorder characterized by various symptoms including dermatological, neurological, and osseous manifestations. These complications often cause cosmetic or functional disturbances, resulting in a significant impact on quality of life (QOL). However, there are limited data on QOL of individuals with NF1 in Japan. Therefore, we studied health-related QOL in patients with NF1 compared with that in general populations and the association with severity grade using EQ-5D. A cross-sectional study was conducted for 73 adult NF1 patients (26 males and 47 females; mean age, 44.16 years). The EQ-5D-5L values and visual analog scale (VAS) in patients with NF1 were 0.738 ± 0.137 and 69.93 ± 19.14, respectively. Both scores were significantly lower in patients with NF1 than in healthy volunteers (p < 0.0001). The score for anxiety/depression was the highest among the five items of EQ-5D. Although we investigated differences in the index value and VAS between stage 2 or less and stage 3 or higher, there was no difference in the scores between groups related to certification criteria for the public medical expenses subsidy system. EQ-5D-5L is a valuable assessment tool for health-related QOL in patients with NF1, but it might not be sufficient for severity certification of NF1 in Japan. We would need the revision of the current certification based on the patients' demand in the future. Our findings might be useful for assessment of therapeutic effects and appropriate resource allocation in the care of patients with NF1.

Prevalence of Itch in German Schoolchildren: A Population-based Study

Itch is a common symptom, but there is limited evidence on the prevalence of itch in children. The aim of this study was to assess the prevalence of itch in schoolchildren. A questionnaire was developed by experts in the field and based on a literature search. The questionnaire was applied in a pilot study of 25 consecutively selected paediatric patients and their parents. It confirmed the high content validity of the questionnaire, and the questionnaire was comparable to hospital records regarding chronic itch (n = 19, mean consistency 89.47%). The questionnaire was distributed among German schoolchildren in 9/12 randomly selected primary schools in Kiel, Germany. Of 1,722 invited students, 443 schoolchildren aged 6–10 years participated, and 26.2% (n = 116) reported itch. The prevalence of acute itch was 20.0% (n = 87), and 14.7% (n = 65) reported chronic itch. Reduced sleep and mood were often related to chronic itch. This study demonstrated that itch is a common symptom in German schoolchildren.

Itch: Epidemiology, clinical presentation, and diagnostic workup

Itch, or pruritus, is the uncomfortable sensation underlying the desire to scratch. Itch is a very common complaint in the general population that can result from dermatologic, systemic (eg, renal, hepatobiliary, endocrine), paraneoplastic, neuropathic, and psychogenic etiologies. Chronic itch is associated with significant sleep disturbances and profoundly reduces overall quality of life. Certain populations, including elderly and African Americans, are at increased risk of experiencing heightened burden of itch. Because of the variable clinical presentation and wide-ranging etiologies, itch presents a challenge for clinicians. The initial evaluation should include a complete blood count, with differential, hepatic, renal, and thyroid function testing along with diabetes screening. Further testing should be guided by history and physical examination findings. There should be a heightened concern for underlying malignancy in individuals older than 60 years of age who have a history of liver disease and diffuse itch less than 12 months of duration. For individuals with chronic pruritus of unknown origin, increased blood eosinophils may serve as a biomarker of T helper cell type 2 polarization and response to immunomodulator therapies. In this first part of a 2-part continuing medical education series, we describe the broader epidemiology and specific conditions associated with itch and the clinical presentation and diagnostic workup for patients with itch.

Validation of the 5-D Itch Scale in Three Ethnic Groups and Exploring Optimal Cutoff Values Using the Itch Numerical Rating Scale

Background

Chronic pruritus is a common and distressing condition that has serious emotional and psychosocial consequences. Due to its subjective nature, self-report questionnaires are widely implemented as cost-effective measures to gauge the severity of chronic pruritus. The current study is aimed at validating the 5-D itch scale in three ethnic groups—Black, Asian, and Hispanic—with the well-validated Itch Numerical Rating Scale (NRS) and Worst Itch NRS (WI-NRS) and developing its cutoff value using receiver operating characteristics (ROC) and inspection of the area under the curve (AUC) across ethnic groups. At the same time, it is aimed at comparing the concurrent prevalence of itch and depression in these populations, who often form ethnic minorities in many countries. The current study addresses the knowledge gap of cultural adaptation of the 5-D pruritus scale for greater usage.

Methods

Community samples of three ethnic groups were recruited from an online platform of Qualtrics and administered the self-report questionnaires of Itch-NRS, 5-D itch scale, and Patient Health Questionnaire-9 (PHQ-9) to measure their pruritus domains, itch intensity, depression screening, and its severity. Informed consent was obtained from all participants. Subgroup analysis was conducted, including concurrent validity and cutoff values compared between each ethnic group. Concurrent prevalence of itch and depression was evaluated using the cutoff value of Itch-NRS and PHQ-9.

Result

A total of 2323 participants were included in the study. A significant positive correlation (p < 0.001) was found between the Itch-NRS, WI-NRS, and 5-D itch scale. The cutoff value of the 5-D itch scale was established for the three ethnic groups using ROC, with a cutoff value of Itch-NRS as a reference.

Conclusions

The 5-D itch scale has demonstrated sound psychometric properties in three ethnic groups and is closely related to Itch-NRS. The analysis of the cutoff value of the 5-D itch scale suggests that different cutoff values should be considered to reduce the inflation of pruritus severity.

More than a skin disease: stress, depression, anxiety levels, and serum neurotrophins in lichen simplex chronicus

BACKGROUND

Lichen simplex chronicus is a dermatological condition due to excessive scratching, with few studies on psychoneuroimmunology.

OBJECTIVE

We aimed to estimate the levels of stress, depression, and anxiety, and to measure serum levels of neurotrophins in patients with lichen simplex chronicus, and to correlate these parameters with the severity of the disease and pruritus.

METHODS

Thirty-six patients with lichen simplex chronicus and 36 age- and sex-matched healthy controls were included. Each participant was administered the Hospital Anxiety and Depression Scale and Perceived Stress Scale questionnaires, along with a visual analog scale for pruritus. Levels of neurotrophins (brain-derived neurotrophic factor, neurotrophin-3, nerve growth factor, glial cell line-derived neurotrophic factor) were determined by ELISA assays.

RESULTS

The scores of Perceived Stress Scale-10, Hospital Anxiety and Depression Scale were statistically higher in patients (p < 0.05 for all). The serum levels of all neurotrophins were significantly lower in patients compared to healthy controls (p < 0.05 for all). Disease severity showed no correlation with all four neurotrophins. In linear regression models applied for increased visual analog scale-pruritus scores and disease severity these two variables were statistically significant predictors (p = 0.043).

STUDY LIMITATIONS

A direct causal relationship was not addressed.

CONCLUSION

Lichen simplex chronicus patients are at risk of increased levels of stress, anxiety, depression, and present decreased levels of neurotrophins, that may suggest a role in the pathophysiology of this disorder.

A case of bleomycin-induced flagellate dermatitis: A case report

The article description and significance to dermatologists: bleomycin flagellate dermatitis is a rare cutaneous manifestation, believed to be due to the lack of bleomycin hydrolase enzyme in the skin, which inactivates bleomycin, resulting in its accumulation. This is thought to be a dose-dependent reaction, and doses over 200 U and higher may increase risk. This case describes a male developing a pruritic, erythematous linear flagellated dermatitis to the lower back after his third cycle of bleomycin, etoposide and cisplatin for a stage 3 seminoma. Pruritis resolved and erythema improved with the treatment of bilastine and desoximetasone cream. It is important to recognize this condition because untreated pruritis may lead to increased impairment of the skin barrier in already immunocompromised patient populations. This may also give further evidence to having ongoing and continuing collaboration between Dermatology and Medical Oncology for any patients presenting with a new rash undergoing chemotherapy treatments.

Therapeutic potential of biologics in prurigo nodularis

INTRODUCTION

Prurigo nodularis (PN) or chronic prurigo of nodular type (CNPG) is a subtype of chronic prurigo with severe pruritus and neuroimmune underlying pathophysiology occurring in a plethora of dermatological, systemic, neurologic, and psychiatric conditions.

AREAS COVERED 

We review the increasing repertoire of biologics in the treatment of CNPG focusing on those targeting interleukins 4, 13, 31, oncostatin M and IgE. Presented information is based on a database research on current clinical trials (clinicaltrials.gov, European Clinical Trials Database (EudraCT), US clinical trial registry ICH-GCP) and a PubMed search for latest publications conducted with the combinations of the terms 'chronic prurigo,' 'prurigo nodularis,' 'pathophysiology,' 'treatment,' 'therapy', and 'biologics.'

EXPERT OPINION

CNPG gets more and more attention as new therapeutic targets have been revealed in recent years, thus allowing the use of targeted approaches. The off-label advent of dupilumab offered advanced insight into the pathogenesis of CNPG and showed an impressive relief of pruritus in the vast majority of patients. New therapies including biologics (e.g. nemolizumab, tralokinumab, lebrikizumab), small molecules (e.g. neurokinin-1 receptor antagonists, janus kinase inhibitors) as well as mu-opioid receptor antagonists and nalbuphine, a μ-antagonist/κ-agonist, are in the pipeline and offer new hope for an improved future patient care.

Chronic Kidney Disease-Associated Itch (CKD-aI) in Children-A Narrative Review

Chronic kidney disease (CKD) is a condition of widespread epidemiology and serious consequences affecting all organs of the organism and associated with significant mortality. The knowledge on CKD is rapidly evolving, especially concerning adults. Recently, more data is also appearing regarding CKD in children. Chronic itch (CI) is a common symptom appearing due to various underlying dermatological and systemic conditions. CI may also appear in association with CKD and is termed chronic kidney disease-associated itch (CKD-aI). CKD-aI is relatively well-described in the literature concerning adults, yet it also affects children. Unfortunately, the data on paediatric CKD-aI is particularly scarce. This narrative review aims to describe various aspects of CKD-aI with an emphasis on children, based on the available data in this population and the data extrapolated from adults. Its pathogenesis is described in details, focusing on the growing role of uraemic toxins (UTs), as well as immune dysfunction, altered opioid transmission, infectious agents, xerosis, neuropathy and dialysis-associated aspects. Moreover, epidemiological and clinical aspects are reviewed based on the few data on CKD-aI in children, whereas treatment recommendations are proposed as well, based on the literature on CKD-aI in adults and own experience in managing CI in children.

Google search trends for itch in Europe: a retrospective longitudinal study

BACKGROUND

Itch is a common symptom in the general population. Affected individuals often do not seek medical consultation and rely on Internet searches to obtain information regarding their itch.

OBJECTIVES

The aim of this study was to attain insights into common concerns of the general population regarding itch can by analysing itch-related Internet search behaviour.

METHODS

Google AdWords Keyword Planner was used to assess search volumes for itch-related terms in 15 European countries between September 2014 and August 2018. All identified keywords were qualitatively categorized. Itch-related terms were descriptively analysed and are shown as number of searches/100 000 inhabitants.

RESULTS

The search volume for the keyword 'itch' per 100 000 inhabitants was highest in Northern Europe, followed by Eastern, Central and Southern Europe. In 4/15 countries, itch was searched for more often in the autumn/winter months compared to in the spring/summer months. Most itch-related terms were related to dermatological conditions such as inflammatory skin diseases (e.g. psoriasis, atopic dermatitis), allergic or immunologic conditions (e.g. urticaria), and infectious diseases or infestations (e.g. scabies). In terms of body location, genitoanal itch dominated the searches. Symptoms and signs related to itch, possible non-dermatological aetiologies, and treatment options were also among the most searched terms.

CONCLUSIONS

These analyses provided for the first time insights into the search behaviour patterns related to itch across Europe. People from Northern and Eastern Europe are more likely to seek online information regarding itch. Causes for the itch, especially dermatological conditions, and genitoanal itch are the most important concerns for Internet users. This unconventional and inexpensive method identifies medical needs of people beyond the medical setting, including people who do not seek medical consultation. Accordingly, the data could be used to guide public health interventions and manage respective inhabitants' medical needs.

Association of Chronic Spontaneous Urticaria With Anxiety and Depression in Adolescents: A Mediation Analysis

Background: Chronic spontaneous urticaria (CSU) is related to psychiatric comorbidities. It is not clear whether the relationship is affected by modifiable factors. Objectives: To investigate whether the effect of CSU on anxiety and depression in adolescents is mediated by the symptoms of itching and sleep disturbance. Methods: Questionnaire survey was conducted among newly enrolled college students. Dermatologists diagnose skin diseases, including CSU, during health examination. Anxiety and depression were measured by the Generalized Anxiety Disorder Scale and Patient Health Questionnaire, respectively. Sleep quality was measured by the Pittsburgh Sleep Quality Index. The symptoms of itching were measured by the numeric rating scale. According to the hypothesis, the mediating effect model was put forward and the structural equation model is used to build the mediation effect model. The mediation effect model was proposed according to the hypothesis and established using a structural equation model. Results: A total of 2,358 students with no history of systemic disease and no pruritus disease (except CSU) were included in the analysis. A total of 393 CSU patients were included, and 1,965 healthy controls were selected based on age and sex matching. CSU was significantly associated with both anxiety and depression when the symptoms of itching and sleep quality were not modeled. A mediation model was proposed as CSU → itching → sleep disturbance → anxiety or depression. Itching and sleep quality mediated 65.4 and 77.6% of CSU's effects on anxiety and depression, respectively, and CSU had no significant direct effect on anxiety or depression in the mediation models. Conclusions: The associations of CSU with anxiety and depression were mediated by the symptoms of itching and sleep disturbance. Effectively reducing the symptoms of itching thereby could increase natural sleep, which can further treat the emotional disorders among patients with CSU.

Prevalence, pathophysiology and management of itch in epidermolysis bullosa

Epidermolysis bullosa (EB) is a highly diverse group of inherited skin disorders, resulting from mutations in genes encoding proteins of the dermoepidermal junction. Itch (pruritus) is one of the most common symptoms across all EB subtypes. It occurs in blistered or wounded sites, or manifests as a generalized phenomenon, thereby affecting both intact skin and healing wounds. The mechanism of pruritus in EB is unclear. It is likely that skin inflammation secondary to barrier disruption, wound healing cascades and dysregulated activation of epidermal sensory nerve endings are all involved in its pathophysiology on the molecular and cellular level. Understanding these mechanisms in depth is crucial in developing optimized treatments for people with EB and improving quality of life. This review summarizes current evidence on the prevalence, mechanisms and management of itch in EB.

Itch processing in the brain

Itch is a sensation defined as the urge to scratch. The central mechanisms of itch are being increasingly studied. These studies are usually based on experimental itch induction methods, which can be classified into the following categories: histamine-induced, induction by other non-histamine chemicals (e.g. cowhage), physically induced (e.g. electrical) and mentally induced (e.g. audio-visual). Because pain has been more extensively studied, some extrapolations to itch can be proposed and verified by experiments. Recent studies suggest that the itch-processing network in the brain could be disrupted in certain diseases. This disruption could be related to the implication of new regions or the exclusion of already engaged brain regions from itch-processing network in the brain.

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.

Social defeat stress exacerbates atopic dermatitis through downregulation of DNA methyltransferase 1 and upregulation of C-C motif chemokine receptor 7 in skin dendritic cells

DNA methylation is an epigenetic modification that regulates gene transcription. DNA methyltransferase 1 (DNMT1) plays an important role in DNA methylation. However, the involvement of DNMT1 and DNA methylation in the pathogenesis of atopic dermatitis (AD) remains unclear. In this study, microarray analysis revealed that peripheral blood mononuclear cells of AD patients with low DNMT1 expression (DNMT1-low) highly expressed dendritic cell (DC) activation-related genes. Also, DNMT1-low AD patients exhibited a higher itch score compared to AD patients with high DNMT1 expression (DNMT1-high). By using an AD-like mouse model induced by the application of Dermatophagoides farinae body ointment, we found that Dnmt1 expression was decreased, while the expression of C-C chemokine receptor type 7 (Ccr7) was upregulated in mouse skin DCs. Furthermore, mice exposed to social defeat stress exhibited Dnmt1 downregulation and Ccr7 upregulation in skin DCs. Additionally, dermatitis and itch-related scratching behavior were exacerbated in AD mice exposed to stress. The relationship between low DNMT1 and itch induction was found in both human AD patients and AD mice. In mouse bone marrow-derived DCs, Ccr7 expression was inhibited by 5-aza-2-deoxycytidine, a methylation inhibitor. Furthermore, in mouse skin DCs, methylation of CpG sites in Ccr7 was modified by either AD induction or social defeat stress. Collectively, these findings suggest that social defeat stress exacerbates AD pathology through Dnmt1 downregulation and Ccr7 upregulation in mouse skin DCs. The data also suggest a role of DNMT1 downregulation in the exacerbation of AD pathology.

Diagnostik von psychischen Faktoren bei chronischem Pruritus

Hintergrund

Pruritus ist ein häufiges und quälendes Symptom in der Bevölkerung sowie in ärztlichen Praxen.

Ziel der Arbeit

Der vorliegende Beitrag gibt einen Überblick über die Systematik psychischer Faktoren in Entstehung bzw. Verlauf des Pruritus sowie Hinweise zu ihrer jeweiligen Diagnostik

Material und Methode

Es handelt sich um eine Überblicksarbeit.

Ergebnisse

Psychische Beeinträchtigungen/Störungen können als Reaktion auf chronischen Pruritus auftreten, z. B. als Anpassungsstörungen, depressive Störungen, Angststörungen. Psychische Faktoren können auch in Entstehung und Verlauf eines chronischen Pruritus eine Rolle spielen, entweder im Zusammenspiel mit organischen Ursachen oder bei deren Fehlen als somatoformer Pruritus oder Pruritus bei coenästhetischer Schizophrenie. Ferner können selbstinduzierte Kratzartefakte mit oder ohne Pruritus im Rahmen von Störungen der Impulskontrolle, Zwangsstörungen oder Artefaktstörungen auftreten. Auch eine primär unabhängige Komorbidität mit einer sonstigen psychischen oder psychosomatischen Störung kann das Management des Pruritus erschweren und den Krankheitsverlauf beeinflussen. Es werden Hinweise zur Diagnostik der genannten Faktoren gegeben.

Diskussion

Die Diagnostik psychischer Einflussfaktoren und psychischer Aspekte des chronischen Pruritus ist komplex. Das wichtigste diagnostische Werkzeug ist die gründliche Anamneseerhebung auch bezüglich psychischer Aspekte. Zusätzlich können psychometrische Instrumente zum Einsatz kommen, die das ärztliche Gespräch jedoch nicht ersetzen.

Black Raspberries and Protocatechuic Acid Mitigate DNFB-Induced Contact Hypersensitivity by Down-Regulating Dendritic Cell Activation and Inhibiting Mediators of Effector Responses

Contact hypersensitivity (CHS) is the most common occupational dermatological disease. Dendritic cells (DCs) mediate the sensitization stage of CHS, while T-cells facilitate the effector mechanisms that drive CHS. Black raspberry (Rubus occidentalis, BRB) and BRB phytochemicals possess immunomodulatory properties, but their dietary effects on CHS are unknown. We examined the effects of diets containing BRB and protocatechuic acid (PCA, a constituent of BRB and an anthocyanin metabolite produced largely by gut microbes), on CHS, using a model induced by 2,4-dinitrofluorobenze (DNFB). Mice were fed control diet or diets supplemented with BRB or PCA. In vitro bone-marrow derived DCs and RAW264.7 macrophages were treated with BRB extract and PCA. Mice fed BRB or PCA supplemented diets displayed decreased DNFB-induced ear swelling, marked by decreased splenic DC accumulation. BRB extract diminished DC maturation associated with reduced Cd80 expression and Interleukin (IL)-12 secretion, and PCA reduced IL-12. Dietary supplementation with BRB and PCA induced differential decreases in IL-12-driven CHS mediators, including Interferon (IFN)-γ and IL-17 production by T-cells. BRB extracts and PCA directly attenuated CHS-promoting macrophage activity mediated by nitric oxide and IL-12. Our results demonstrate that BRB and PCA mitigate CHS pathology, providing a rationale for CHS alleviation via dietary supplementation with BRB or BRB derived anthocyanins.

New and emerging treatments for inflammatory itch

OBJECTIVE

To summarize recent therapeutic developments for chronic pruritus with a focus on allergic and type 2 inflammatory pathways.

DATA SOURCES

Literature search of PubMed, industry websites, and review of the ClinicalTrials.gov database.

STUDY SELECTIONS

Peer-reviewed publications and public disclosures by industry relating to chronic pruritus pathophysiology and therapeutics.

RESULTS

Histamine and immunoglobulin E remain primary targets for the treatment of itch in the setting of chronic urticaria. More recently, blockade of type 2 immune cell-associated cytokines, including interleukin (IL) 4, IL-13, and IL-31, and the epithelial cell-derived cytokines, specifically IL-33 and thymic stromal lymphopoietin, has and is revolutionizing the treatment of chronic pruritic dermatoses, such as atopic dermatitis and prurigo nodularis. Other novel targets include histamine receptor 4, Janus kinases, κ-opioid receptor, neurokinin 1 receptor, and phosphodiesterase 4.

CONCLUSION

Advances in our understanding of the neuroimmunology of chronic pruritus have led to the identification of new therapeutic targets and the rapid development of cutting-edge clinical trials. Although incredible advances have already been made, chronic itch continues to be an area of great unmet need.

Chronic nodular prurigo: clinical profile and burden. A European cross-sectional study

BACKGROUND

Chronic nodular prurigo (CNPG) is a condition characterized by chronic itch, a prolonged scratching behaviour and the presence of pruriginous nodules. A comprehensive understanding of this condition, especially regarding its clinical characteristics and impact on quality of life is still lacking.

OBJECTIVES

Aim of this pan-European multicentre cross-sectional study was to establish the clinical profile of CNPG, including its associated burden.

METHODS

Fifteen centres from 12 European countries recruited CNPG patients presenting at the centre or using the centres' own databases. Patients were asked to complete a questionnaire in paper or electronic format. Demography, current co-morbidities, underlying disease, itch intensity, additional sensory symptoms, quality of life, highest burden and emotional experience of itch were assessed.

RESULTS

A total of 509 patients (210 male, median age: 64 years [52; 72]) were enrolled. Of these, 406 reported itch and CNPG lesions in the previous 7 days and qualified to complete the whole questionnaire. We recorded moderate to severe worst itch intensity scores in the previous 24 h. Scores were higher in patients with lower educational levels and those coming from Eastern or Southern Europe. Most patients experience itch often or always (71%) and report that their everyday life is negatively affected (53%). Itch intensity was considered to be the most burdensome aspect of the disease by 49% of the patients, followed by the visibility of skin lesions (21%) and bleeding of lesions (21%). The majority of patients was unaware of an underlying condition contributing to CNPG (64%), while psychiatric diseases were the conditions most often mentioned in association with CNPG (19%).

CONCLUSIONS

This multicentre cross-sectional study shows that itch is the dominant symptom in CNPG and reveals that the profile of the disease is similar throughout Europe.

Physiology and Pathophysiology of Itch

Itch is a topic to which everyone can relate. The physiological roles of itch are increasingly understood and appreciated. The pathophysiological consequences of itch impact quality of life as much as pain. These dynamics have led to increasingly deep dives into the mechanisms that underlie and contribute to the sensation of itch. When the prior review on the physiology of itching was published in this journal in 1941, itch was a black box of interest to a small number of neuroscientists and dermatologists. Itch is now appreciated as a complex and colorful Rubik's cube. Acute and chronic itch are being carefully scratched apart and reassembled by puzzle solvers across the biomedical spectrum. New mediators are being identified. Mechanisms blur boundaries of the circuitry that blend neuroscience and immunology. Measures involve psychophysics and behavioral psychology. The efforts associated with these approaches are positively impacting the care of itchy patients. There is now the potential to markedly alleviate chronic itch, a condition that does not end life, but often ruins it. We review the itch field and provide a current understanding of the pathophysiology of itch. Itch is a disease, not only a symptom of disease.