Psychometric evaluation of the multidimensional Uraemic Pruritus in Dialysis patients (UP-Dial) scale: comparison of haemodialysis and peritoneal dialysis patients with chronic pruritus.

BACKGROUND: High-quality patient-reported outcome (PRO) measures for dialysis patients with chronic pruritus are urgently needed. However, no known, well-validated multidimensional tools have been investigated to measure pruritus symptoms in dialysis patients. OBJECTIVES: To examine the psychometric properties of a multidimensional tool of chronic pruritus, the Uraemic Pruritus in Dialysis patients (UP-Dial) 14-item scale, by comparing haemodialysis and peritoneal dialysis modality. METHODS: This validation study used data from the Thai Renal Outcomes Research-Uraemic Pruritus, a prospective, multicentre, longitudinal study. Data for this study were collected from 1 February 2019 to 31 May 2022. The adult sample of 226 haemodialysis and 327 peritoneal dialysis patients fulfilled the criteria of chronic pruritus based on the International Forum for the Study of Itch. Psychometric properties of the UP-Dial included validity and reliability, as measured across haemodialysis and peritoneal dialysis patients. Patients completed a set of anchor-based measurement tools, including global itching, Dermatology Life Quality Index (DLQI), EuroQoL-5 dimension-5 level (EQ-5D-5L), Kidney Disease Quality of Life-36 (KDQOL-36), Pittsburgh Sleep Quality Index (PSQI), global fatigue, Somatic Symptom Scale-8 (SSS-8) and Patient Health Questionnaire-9 (PHQ-9). RESULTS: From the patient's perspective, face validity was satisfactory for both dialysis samples. Psychometric analyses of the UP-Dial for each dialysis sample had good convergent validity. Spearman rho correlations indicate a positively strong correlation (0.73-0.74) with global itching, a positively moderate correlation (0.33-0.58) with DLQI, PSQI, global fatigue, SSS-8 and PHQ-9, and a negatively moderate correlation (-0.39 to -0.58) with EQ-5D-5L and KDQOL-36. The discriminant validity was satisfactory with a group of moderate and severe burden of pruritus for both dialysis samples. For scale reliability, the UP-Dial revealed excellent internal consistency (Cronbach's α = 0.89 and McDonald's ω = 0.90) and reproducibility (intraclass correlation 0.84-0.85) for both dialysis samples. Regarding psychometric properties, no statistically significant differences between dialysis samples were observed (all P > 0.05). CONCLUSIONS: The findings reaffirm good measurement properties of the UP-Dial 14-item scale in haemodialysis and peritoneal dialysis patients with chronic pruritus. These suggest a transferability of the UP-Dial as a PRO measure in clinical trial and practice settings.

Itch is a common symptom in chronic kidney disease, especially for people experiencing end-stage kidney disease and receiving dialysis. Itching among dialysis patients can present and affect any part of the body. Although there has been improvement in dialysis treatment over time, chronic itching (itching lasting more than 6 weeks) remains under-recognized in dialysis patients. In recent years, a specific clinical tool called the Uraemic Pruritus in Dialysis patients (UP-Dial) has been developed to assess the severity and burden of itching in dialysis patients. However, a comprehensive tool for evaluating itching symptoms has yet to be tested in a large dialysis population (haemodialysis and peritoneal dialysis). We examined and validated the measurement properties of the UP-Dial scale in an adult sample of 226 haemodialysis and 327 peritoneal dialysis patients with chronic itching. Our study found that the UP-Dial had good measurement properties for evaluating the burden of itching symptoms among haemodialysis and peritoneal dialysis patients with chronic itching. Our findings support the use of UP-Dial to compare treatments for chronic itching clinical trials and track treatment responses in daily practice.

Chronic Itch Affects Patients' Ability to Experience Pleasure: Anhedonia in Itchy Disorders.

Anhedonia, the reduced ability to experience pleasure, is a prevalent symptom in various psychiatric disorders, but has not been investigated in dermatological conditions, particularly those characterized by chronic itch. This study aimed to examine the prevalence and clinical correlates of anhedonia in patients with chronic itch. A cross-sectional study was conducted in 137 patients with chronic itch, classified according to the International Forum for the Study of Itch (IFSI) classification. Anhedonia was assessed using the Snaith-Hamilton Pleasure Scale (SHAPS) and Anticipatory and Consummatory Interpersonal Pleasure Scale (ACIPS). Itch severity, quality of life, and psychological distress were assessed using the Visual Analogue Scale (VAS), Verbal Rating Scale (VRS), ItchyQoL, and Hospital Anxiety and Depression Scale (HADS), respectively. The mean SHAPS score was 1.0 ± 1.7 points, and the mean ACIPS total score was 76.9 ± 16.2 points. In the study sample, 13.1% of patients were identified as anhedonic, with a higher prevalence observed in those with severe and very severe itch. Anhedonia was significantly correlated with itch severity (R = 0.2, p=0.02 for 24 h VASmean and SHAPS; R = 0.2, p = 0.01 for 24 h VASmax and SHAPS), anxiety symptoms (R = 0.3, p < 0.001 for SHAPS and HADS-anxiety), depression symptoms (R = 0.4, p < 0.001 for SHAPS and HADS-depression), and impairment in quality of life (R = 0.2, p = 0.014 for SHAPS and ItchyQoL). Anhedonia is a significant and prevalent aspect of psychological distress in patients with chronic itch. Addressing this symptom may not only improve patients' overall mental health but also enhance the effectiveness of treatments for chronic itch. Future research is needed to elucidate further the mechanisms underlying the relationship between anhedonia and chronic itch and to develop targeted interventions for this population.

A Qualitative Tool to Guide in the Interpretation of the Numerical Rating Scale for Pruritus Intensity in Patients with Atopic Dermatitis.

Atopic dermatitis is a cutaneous inflammatory disease characterized by intense pruritus, which is often underestimated despite its direct impact on patients' health-related quality of life and the high burden it poses. The authors' goal was to design a qualitative tool to guide patients and healthcare professionals in their assessment and interpretation of pruritus intensity using a numerical rating scale. The draft of this tool, henceforth "guideline", was developed based on a systematic literature review and focus groups comprising patients and a scientific committee. This draft was validated with an independent group of patients and the final version was designed following their feedback. According to the results of the systematic review, pruritus impacts 6 health-related quality of life domains: sleep quality; emotional status; overall health-related quality of life; physical function; social/sexual activity; productivity, particularly affecting sleep quality and the emotional domain. Patients considered that physical function was the most strongly affected domain, followed by sleep quality and emotional well-being, establishing that a minimum pruritus intensity of 4 and 7 points impacts moderately and severely, respectively, on the different domains of patients' health- related quality of life. The guideline may help patients and healthcare professionals to interpret and assess pruritus intensity using a numerical rating scale and to understand the impact of pruritus on patients' health-related quality of life.

Acceptability and perceived benefits of validated pruritus assessment instruments in the dermatological office and clinic: The perspectives of patients and physicians.

BACKGROUND: Several patient-reported outcome measures (PROMs) have been developed for research to assess the multiple dimensions of chronic pruritus (CP). The acceptability and perceived benefits of their use in clinical practice remain unknown. OBJECTIVES: To assess the acceptability and perceived benefits of validated PROMs from the perspective of patients and physicians in dermatological offices and clinics. METHODS: Patients with CP due to atopic dermatitis, psoriasis, chronic prurigo or chronic urticaria were recruited at 10 dermatological offices and two dermatological clinics in Germany. Patients completed a set of validated PROMs on pruritus intensity (numerical rating scale, NRS), symptom control (itch-controlled days, ItchCD), quality of life (Dermatology Life Quality Index, DLQI; 5-pruritus life quality, 5PLQ) and general health status (EuroQol, EQ-VAS). Acceptability (relevance, difficulty of completion, length) and benefits (usefulness, feasibility) of these tools were assessed on a NRS (0-10) by patients and physicians, respectively. Data were analysed descriptively. Linear regression was used to study potential associations between age, sex, occupation, office versus clinic, change of therapy and physician-reported benefits. RESULTS: N = 523 patients (46% male, average age: 53.5 years) participated. Acceptability of PROMs by patients was high, indicated by low difficulty (Md = 0, IQR = 0-1 for all PROMs) and high relevance (Md = 8, IQR = 4-10 for all PROMs). Also, most patients (89-95%) rated length of the questionnaires as 'exactly right'. Physicians rated the NRS as the most beneficial instrument (feasibility: Md = 8, IQR = 6-10; usefulness: Md = 9, IQR = 7-10). Hierarchical linear regression revealed that only recruitment site (dermatological office vs. clinic) was significantly associated with usefulness and feasibility (higher ratings for clinical context; ßs = 0.149-0.258, ps <0.05; except feasibility for EQ5d, ß = ns). CONCLUSIONS: PROMs are welcomed by patients, while physicians consider instruments measuring pruritus intensity and impairment of quality of life as beneficial for the clinical routine. Widespread implementation of PROMs in daily clinical work is needed to improve care.

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.

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.

[Research progress on clinical and mechanisms of chronic pruritus with anxiety and depression].

Chronic pruritus seriously affects the quality of life of patients, which is closely related to stress, anxiety and depression. Prolonged and repeated pruritus can induce negative emotions such as anxiety and depression, while continued increased negative emotions can also promote exacerbation of pruritus, which drives the itch scratch cycle, thereby further aggravating skin damage. More and more studies have explored the mechanism of pruritus, anxiety and depression. This article mainly reviews the clinical relationship between pruritus and anxiety, depression and the new progress of its possible mechanism, providing reference for the prevention, control and effective treatment of chronic pruritus, anxiety and depression.

Fibrates for Itch (FITCH) in Fibrosing Cholangiopathies: A Double-Blind, Randomized, Placebo-Controlled Trial.

BACKGROUND AND AIMS: Pruritus may seriously impair quality of life in patients with cholestatic diseases such as primary or secondary sclerosing cholangitis (PSC, SSC) and primary biliary cholangitis (PBC). Pharmacologic strategies show limited efficacy and can provoke serious side effects. We hypothesized that bezafibrate, a broad peroxisome proliferator-activated receptor (PPAR) agonist, relieves cholestasis-associated itch by alleviating hepatobiliary injury. The aim of this investigator-initiated FITCH trial (Fibrates for cholestatic ITCH) was to assess effects of bezafibrate on pruritus in patients with PSC, PBC, and SSC. METHODS: Patients with moderate to severe pruritus (≥5 of 10 on visual analog scale [VAS]) due to PSC, PBC, or SSC were recruited for this double-blind, randomized, placebo-controlled trial between 2016 and 2019. Patients received once-daily bezafibrate (400 mg) or placebo for 21 days. The primary end point was ≥50% reduction of pruritus (VAS; intention-to-treat). RESULTS: Of 74 randomized patients, 70 completed the trial (95%; 44 PSC, 24 PBC, 2 SSC). For the primary end point, bezafibrate led in 45% (41% PSC, 55% PBC) and placebo in 11% to ≥50% reduction of severe or moderate pruritus (P = .003). For secondary end points, bezafibrate reduced morning (P = .01 vs placebo) and evening (P = .007) intensity of pruritus (VAS) and improved the validated 5D-Itch questionnaire (P = .002 vs placebo). Bezafibrate also reduced serum alkaline phosphatase (-35%, P = .03 vs placebo) correlating with improved pruritus (VAS, P = .01) suggesting reduced biliary damage. Serum bile acids and autotaxin activity remained unchanged. Serum creatinine levels tended to mildly increase (3% bezafibrate, 5% placebo, P = .14). CONCLUSIONS: Bezafibrate is superior to placebo in improving moderate to severe pruritus in patients with PSC and PBC. TRIAL REGISTRATION: Netherlands Trial Register, ID: NTR5436 (August 3, 2015), ClinicalTrials.gov ID: NCT02701166 (March 2, 2016).

Validation of Relationship between Patients' Descriptions of Pruritus and Patient-burden of Chronic Pruritus using Structural Equation Modelling.

Patients with chronic itch describe their pruritus in a wide variety of ways. However, these subjective descriptions are often not taken into consideration by physicians. This study aimed to validate patients' descriptions of pruritus, and to investigate the relationship between various descriptions of pruritus and the patient burden of chronic pruritus by examining the mediating effects of sleep disturbance and sexual dysfunction on patient's quality of life, as predicted by various descriptions of pruritus. Exploratory and confirmatory factor analyses were performed to identify the factor structure measured by 11 descriptions of pruritus. The study then analysed differences in the degree of sleep disturbance, sexual dysfunction, and quality of life deterioration factors using a structural equation modelling method. Using data from 419 patients with chronic pruritus, 11 descriptions of pruritus were classified into 2 groups: (i) sensory pruritus (i.e. stinging, stabbing, burning, painful, formication, throbbing, and cold) that are linked with descriptions of pruritus patterns; and (ii) affective pruritus (i.e. annoying, unbearable, worrisome, and warm) from patient reports of psychological or emotional distress. The study found that affective pruritus decreases patient's quality of life either directly or indirectly through sleep disturbance. In conclusion, clues about a patients' sleep disturbance or poor quality of life can be obtained through their descriptions of pruritus.

The Nocebo Effect: A Review of Contemporary Experimental Research.

BACKGROUND: Nocebo effect, the occurrence of adverse symptoms fallowing an inactive treatment, is much less understood than its opposite, placebo effect. This systematic review of contemporary studies exploring the nocebo effect focuses on (1) the mechanisms underlying the nocebo effect, (2) the characteristics of participants exhibiting a more intensive nocebo response, and (3) the circumstances that might reduce or prevent the nocebo effect. METHOD: We included experimental nocebo studies published in English that examined the occurrence of nocebo in various domains (i.e., types of sensations and symptoms) and different levels of nocebo response (e.g., performance, self-assessment) and in different populations of participants (healthy and clinical). Using Web of Science, PsycInfo and PubMed, we identified 25 papers (35 studies) that met our criteria with a total of N = 2614 participants, mostly healthy volunteers. RESULTS: Nocebo was invoked by manipulating expectations, conditioning or both. A narrative content synthesis was conducted. Nocebo was successfully invoked in a range of domains (e.g., pain, nausea, itch, skin dryness) and levels (sensory, affective, psychological, and behavioral). Various characteristics of the conditioning procedure and participants' emotions, expectations, and dispositions are found to be related to the nocebo response, which sheds insight into the possible mechanisms of the nocebo effect. Strategies successful and unsuccessful in diminishing the nocebo response are identified. Limitations of this review include a small sample of studies. CONCLUSION: These findings point to the universality of nocebo as well as to the importance of participant characteristics and experimental circumstances in invoking the nocebo effect. Further research should examine the nocebo effect in clinical populations.

Plasma Steroids and Endocannabinoids Used as Biomarkers to Assess the Pruritus Severity of Patients With Prurigo Nodularis.

BACKGROUND: Prurigo nodularis (PN) as an extremely pruritic and hyperplastic chronic dermatosis induces psychologically and physiologically stressful responses. PN-induced responses in the hypothalamic-pituitary-adrenal (HPA), hypothalamic-pituitary-gonadal (HPG) axes and endocannabinoid system (ECS) are abnormal. Extant studies on the PN's pathogenesis mostly focused on the PN's psychological responses. To date, the PN's physiological responses remain not been fully uncovered yet. OBJECTIVES: To investigate the PN-induced physiological responses via the levels of five steroids and two endocannabinoids combined with their ratios in plasma and examine the association between the psychological and physiological responses. MATERIALS AND METHODS: Thirty-six patients with PN, 36 age- and gender-matched healthy controls were recruited. The PN's psychological symptoms including pruritus severity, pain and life quality were measured with the visual analog scale, the prurigo score index, numerical rating scale, verbal rating scale and dermatology life quality index. Their concentrations of steroids and endocannabinoids were determined with liquid chromatography-tandem mass spectrometry. RESULTS: Compared to controls, the PN patients showed lower plasma levels in cortisol, cortisone, N-arachidonoyl-ethanolamine (AEA), and the ratio of DHEA to 1-arachydonoyl glycerol (1-AG), which negatively moderately and over correlated with PN's symptoms, especially with the pruritus severity. Additionally, the PN patients exhibited higher levels in the ratios of testosterone and 1-AG to cortisol, which positively moderately and over correlated with pruritus severity. Thus, the seven biomarkers would be sensitive and reliable biomarkers for assessing the pruritus severity of PN because they met the screening criteria that the biomarkers show intergroup differences and showed moderate or over correlation with the pruritus severity of PN. CONCLUSIONS: To the best of our knowledge, this is the first study exploring PN-induced physiological responses. The findings suggest that alterations in these three endocrine systems may lead to new insights to psychological mechanisms and responses to prurigo nodularis.

Plasma Steroids and Endocannabinoids Used as Biomarkers to Assess the Pruritus Severity of Patients With Prurigo Nodularis. / [Artículo traducido] Esteroides y endocannabinoides plasmáticos utilizados como biomarcadores para evaluar la gravedad del prurito de los pacientes con prúrigo nodular.

BACKGROUND: Prurigo nodularis (PN) as an extremely pruritic and hyperplastic chronic dermatosis induces psychologically and physiologically stressful responses. PN-induced responses in the hypothalamic-pituitary-adrenal, hypothalamic-pituitary-gonadal axes and endocannabinoid system are abnormal. Extant studies on the PN's pathogenesis mostly focused on the PN's psychological responses. To date, the PN's physiological responses remain not been fully uncovered yet. OBJECTIVES: To investigate the PN-induced physiological responses via the levels of 5steroids and 2endocannabinoids combined with their ratios in plasma and examine the association between the psychological and physiological responses. MATERIALS AND METHODS: Thirty-six patients with PN, 36 age- and gender-matched healthy controls were recruited. The PN's psychological symptoms including pruritus severity, pain and life quality were measured with the visual analogue scale, the prurigo score index, numerical rating scale, verbal rating scale and dermatology life quality index. Their concentrations of steroids and endocannabinoids were determined with liquid chromatography-tandem mass spectrometry. RESULTS: Compared to controls, the PN patients showed lower plasma levels in cortisol, cortisone, N-arachidonoyl-ethanolamine, and the ratio of DHEA to 1-arachydonoyl glycerol (1-AG), which negatively moderately and over correlated with PN's symptoms, especially with the pruritus severity. Additionally, the PN patients exhibited higher levels in the ratios of testosterone and 1-AG to cortisol, which positively moderately and over correlated with pruritus severity. Thus, the 7biomarkers would be sensitive and reliable biomarkers for assessing the pruritus severity of PN because they met the screening criteria that the biomarkers show intergroup differences and showed moderate or over correlation with the pruritus severity of PN. CONCLUSIONS: To the best of our knowledge, this is the first study exploring PN-induced physiological responses. The findigs suggest that alterations in these 3endocrine systems may lead to new insights to psychological mechanisms and responses to PN.

The Neurokinin-1 Receptor is Expressed with Gastrin-Releasing Peptide Receptor in Spinal Interneurons and Modulates Itch.

The neurokinin-1 receptor (NK1R; encoded by Tacr1) is expressed in spinal dorsal horn neurons and has been suggested to mediate itch in rodents. However, previous studies relied heavily on neurotoxic ablation of NK1R spinal neurons, which limited further dissection of their function in spinal itch circuitry. To address this limitation, we leveraged a newly developed Tacr1CreER mouse line to characterize the role of NK1R spinal neurons in itch. We show that pharmacological activation of spinal NK1R and chemogenetic activation of Tacr1CreER spinal neurons increases itch behavior in male and female mice, whereas pharmacological inhibition of spinal NK1R suppresses itch behavior. We use fluorescence in situ hybridization (FISH) to characterize the endogenous expression of Tacr1 throughout the superficial and deeper dorsal horn (DDH), as well as the lateral spinal nucleus (LSN), of mouse and human spinal cord. Retrograde labeling studies in mice from the parabrachial nucleus (PBN) show that less than 20% of superficial Tacr1CreER dorsal horn neurons are spinal projection neurons, and thus the majority of Tacr1CreER are local interneurons. We then use a combination of in situ hybridization and ex vivo two-photon Ca2+ imaging of the mouse spinal cord to establish that NK1R and the gastrin-releasing peptide receptor (GRPR) are coexpressed within a subpopulation of excitatory superficial dorsal horn (SDH) neurons. These findings are the first to suggest a role for NK1R interneurons in itch and extend our understanding of the complexities of spinal itch circuitry.SIGNIFICANCE STATEMENT The spinal cord is a critical hub for processing somatosensory input, yet which spinal neurons process itch input and how itch signals are encoded within the spinal cord is not fully understood. We demonstrate neurokinin-1 receptor (NK1R) spinal neurons mediate itch behavior in mice and that the majority of NK1R spinal neurons are local interneurons. These NK1R neurons comprise a subset of gastrin-releasing peptide receptor (GRPR) interneurons and are thus positioned at the center of spinal itch transmission. We show NK1R mRNA expression in human spinal cord, underscoring the translational relevance of our findings in mice. This work is the first to suggest a role for NK1R interneurons in itch and extends our understanding of the complexities of spinal itch circuitry.

Direct evidence that the brain reward system is involved in the control of scratching behaviors induced by acute and chronic itch.

In the present study, we demonstrated that there is a direct relationship between scratching behaviors induced by itch and functional changes in the brain reward system. Using a conditional place preference test, the rewarding effect was clearly evoked by scratching under both acute and chronic itch stimuli. The induction of ΔFosB, a member of the Fos family of transcription factors, was observed in dopamine transporter (DAT)-positive dopamine neurons in the ventral tegmental area (VTA) of mice suffering from a chronic itch sensation. Based on a cellular analysis of scratching-activated neurons, these neurons highly expressed tyrosine hydroxylase (TH) and DAT genes in the VTA. Furthermore, in an in vivo microdialysis study, the levels of extracellular dopamine in the nucleus accumbens (NAcc) were significantly increased by transient scratching behaviors. To specifically suppress the mesolimbic dopaminergic pathway using pharmacogenetics, we used the TH-cre/hM4Di mice. Pharmacogenetic suppression of mesolimbic dopaminergic neurons significantly decreased scratching behaviors. Under the itch condition with scratching behaviors restricted by an Elizabethan collar, the induction of ΔFosB was found mostly in corticotropin-releasing hormone (CRH)-containing neurons of the hypothalamic paraventricular nucleus (PVN). These findings suggest that repetitive abnormal scratching behaviors under acute and chronic itch stimuli may activate mesolimbic dopamine neurons along with pleasant emotions, while the restriction of such scratching behaviors may initially induce the activation of PVN-CRH neurons associated with stress.

The characteristics and impact of pruritus in adult dermatology patients: A prospective, cross-sectional study.

BACKGROUND: Pruritus often accompanies chronic skin diseases, exerting considerable burden on many areas of patient functioning; this burden and the features of pruritus remain insufficiently characterized. OBJECTIVE: To investigate characteristics, including localization patterns, and burden of pruritus in patients with chronic dermatoses. METHODS: We recruited 800 patients with active chronic skin diseases. We assessed pruritus intensity, localization, and further characteristics. We used validated questionnaires to assess quality of life, work productivity and activity impairment, anxiety, depression, and sleep quality. RESULTS: Nine out of every 10 patients had experienced pruritus throughout their disease and 73% in the last 7 days. Pruritus often affected the entire body and was not restricted to skin lesions. Patients with moderate to severe pruritus reported significantly more impairment to their sleep quality and work productivity, and they were more depressed and anxious than control individuals and patients with mild or no pruritus. Suicidal ideations were highly prevalent in patients with chronic pruritus (18.5%) and atopic dermatitis (11.8%). CONCLUSIONS: Pruritus prevalence and intensity are very high across all dermatoses studied; intensity is linked to impairment in many areas of daily functioning. Effective treatment strategies are urgently required to treat pruritus and the underlying skin disease.

Estimated Frequency of Psychodermatologic Conditions in Alberta, Canada.

BACKGROUND: Psychodermatologic disorders are difficult to identify and treat. Knowledge about the prevalence of these conditions in dermatological practice in Canada is scarce. This hampers our ability to address potential gaps and establish optimal care pathways. OBJECTIVES: To provide an estimate of the frequencies of psychodermatologic conditions in dermatological practice in Alberta, Canada. METHODS: Two administrative provincial databases were used to estimate the prevalence of potential psychodermatological conditions in Alberta from 2014 to 2018. Province-wide dermatology claims data were examined to extract relevant International Classification of Disease codes as available. Claims were linked with pharmacy dispensation data to identify patients who received at least 1 psychoactive medication within 90 days of the dermatology claim. RESULTS: Of 243 963 patients identified, 28.6% had received at least 1 psychotropic medication (mean age: 47.9 years; 67.5% female). Rates of concurrent psychotropic medications were highest for pruritus and related conditions (46.7%), followed by urticaria (44.5%) and hyperhidrosis (32.8%). Among patients with psychotropic medications, rates of antidepressants were highest (56.3%), followed by anxiolytics (37.1%). Across billing codes, besides hyperhidrosis (71.2%), diseases of hair (61.4%) and psoriasis (59.1%) had the highest rates of antidepressant dispensations. Patients with atopic dermatitis had the highest rates for anxiolytic prescriptions (54.3%). CONCLUSION: In a 5-year window, more than a quarter of the identified dermatology patients in Alberta received at least 1 psychotropic medication, pointing to high rates of potential psychodermatologic conditions and/or concurrent mental health issues in dermatology. Diagnostic and care pathways should include a multidisciplinary approach to better identify and treat these conditions.

Thymol activates TRPM8-mediated Ca2+ influx for its antipruritic effects and alleviates inflammatory response in Imiquimod-induced mice.

Psoriasis is a highly prevalent chronic dermatitis, characterized by widespread skin inflammation and spontaneous itch. Given the adverse reactions and drug dependence of current treatment, new drugs for psoriasis therapy are urgently needed. This study aims to explore the anti-psoriatic effects of thymol in imiquimod (IMQ) induced mice, and elucidate the potential mechanisms for its therapeutic activities. Thymol reduced the scratching behavior in IMQ mice, and activated Ca2+ response in cervical DRG neurons via TRPM8 channel. Also, thymol alleviated psoriasis-like skin lesions, and attenuated the enhanced infiltration of dermal neutrophils, dendritic cells (DCs) and Th17 cells. In addition, it reversed the upregulated expression of pro-inflammatory cytokines in the skin (TNF-α, IL-22, IL-23, IL-17A, IL-17F, IL-17C, IL-6, IL-1ß and IFN-γ) and serum (TNF-α, IL-6, IL-1ß, IL-17A and IFN-γ). Our results indicated that thymol can effectively ameliorate pruritus and the symptoms of psoriasis-like inflammation induced by IMQ, which makes it a promising drug for the treatment of psoriasis.

Measurement properties of the Patient-Reported Outcomes Measurement Information System Itch Questionnaire item banks in adults with atopic dermatitis.

BACKGROUND: The Patient-Reported Outcomes Measurement Information System (PROMIS) Itch Questionnaire (PIQ) was recently developed. OBJECTIVE: To validate PIQ short forms in adults with AD. METHODS: Self-administered questionnaires and skin examinations were performed in 239 adults with atopic dermatitis (AD) in a dermatology practice setting. RESULTS: PIQ items had good content validity. PIQ item bank T-scores strongly correlated with each other, moderately correlated with numeric and verbal rating scales for worst or average itch and with itch frequency, moderately to strongly correlated with patient-oriented eczema measure, and weakly to moderately correlated with the Eczema Area and Severity Index and Objective-Scoring AD (Spearman correlations, P < .0001). There were significant and stepwise increases of T-scores for all item banks with increasing patient-reported global severity (Wilcoxon rank sum test, P < .0001). However, there was limited ability to discriminate between the lowest or highest 2 levels of AD or itch severity. Item banks showed good internal consistency (Cronbach α, 0.91-0.95). No differential item functioning was identified by age, sex, race/ethnicity, or educational level. There were floor effects for total scores, particularly in almost clear/mild AD or itch. LIMITATIONS: Single-center study. CONCLUSIONS: PIQ item bank short forms showed good content and construct validity and are feasible for potential use in clinical trials and practice.

Measuring atopic eczema symptoms in clinical practice: The first consensus statement from the Harmonising Outcome Measures for Eczema in clinical practice initiative.

BACKGROUND: Measuring patient-centered outcomes in clinical practice is valuable for monitoring patients and advancing real-world research. A new initiative from the Harmonising Outcome Measures for Eczema (HOME) group aims to recommend what might be recorded for atopic eczema patients in routine clinical care. OBJECTIVES: Prioritize outcome domains to measure atopic eczema in clinical practice and select valid and practical outcome measurement instruments for the highest-priority domain. METHODS: An online survey of HOME members identified and ranked 21 possible health domains. Suitable instruments were then selected for the top-prioritized domain at the HOME VI meeting, using established consensus processes informed by systematic reviews of instrument quality. RESULTS: Patient-reported symptoms was the top-prioritized domain. In accordance with psychometric properties and feasibility, there was consensus that the recommended instruments to measure atopic eczema symptoms in clinical practice are the POEM, the PO-SCORAD index, or both. The numeric rating scale for itch received support pending definition and validation in atopic eczema. CONCLUSION: Following the first step of the HOME Clinical Practice initiative, we endorse using the POEM, the PO-SCORAD index, or both for measuring atopic eczema symptoms in clinical practice. Additional high-priority domains for clinical practice will be assessed at subsequent HOME meetings.

Exploring the relation between the EQ-5D-5L pain/discomfort and pain and itching in a sample of burn patients.

BACKGROUND: The EQ-5D domain pain/discomfort (PD) uses one item to capture pain and other aspects of discomfort, like itching. This study explored how pain, itching and the EQ-5D-5L PD domain relate to each other in a sample of burn patients. METHODS: Adult burn patients completed the EQ-5D-5L and the Patient and Observer Scar Assessment Scale (POSAS) 5-7 years after sustaining their injury. The POSAS includes a separate pain and an itching item. Spearman's correlation coefficient established the association between the EQ-5D-5L PD and the POSAS pain and itching item. With multivariable regression analysis the linear association between the POSAS pain and itching item and EQ-5D-5L PD domain was tested. RESULTS: Data from 245 patients were included. Mean EQ-5D-5L index value was 0.87 and 39.2% reported at least slight problems on the EQ-5D-5L PD domain. Most patients gave corresponding answers on the EQ-5D-5L PD domain and on the POSAS pain (73%) and itching (70%) item. Spearman correlation coefficients of the EQ-5D-5L PD domain with the POSAS pain and itching were 0.468 (p < 0.001) and 0.473 (p < 0.001), respectively. Among respondents with pain and without itching and respondents with itching and without pain, Spearman correlation coefficients were 0.585 (p = 0.076) and 0.408 (p = 0.001), respectively. POSAS pain (unstandardized Beta = 0.14) and POSAS itching (unstandardized Beta = 0.08) were significantly associated with EQ-5D-5L PD domain (p < 0.001). CONCLUSIONS: Our findings indicate that, in a sample of burn patients, pain and itching are captured by the broader EQ-5D-5L PD domain. The EQ-5D-5L PD domain can thus be used to assess pain and itching in relation to HRQL, but the POSAS pain and itching items are more sensitive. The EQ-5D-5L is, however, no replacement of the POSAS when the POSAS is used for its primary aim; assessment of scar quality. TRIAL REGISTRATION: Netherlands Trial Register (NTR6407).