Psychosomatic cofactors and psychiatric comorbidity in patients with chronic itch

[Recommended diagnostics for pruritus affecting primary non-lesional skin]

BACKGROUND

Chronic pruritus affecting primary non-lesional skin (CPNL) manifests as a common symptom across a spectrum of diseases spanning various medical specialties. Given the diverse etiological factors involved, diagnosing the underlying condition poses a significant challenge.

OBJECTIVES

To provide a comprehensive overview of clinical, laboratory, and imaging diagnostics for CPNL.

MATERIALS AND METHODS

A thorough literature search on the diagnostics of chronic pruritus was conducted using PubMed with specific keywords "chronic pruritus AND non-lesional skin", "chronic itch AND non-lesional skin", "chronic pruritus AND diagnostics", "chronic itch AND diagnostics", "CKD-aP", "hepatic pruritus", "cholestatic pruritus", and "myeloproliferative neoplasms AND pruritus".

RESULTS

A systematic diagnostic approach is recommended for patients with CPNL, guided by the prevalence of pruritus-associated diseases. Initial basic diagnostics facilitate a cost-effective and focused evaluation during the initial medical assessment. Information pertaining to underlying diseases can be further refined through specialized diagnostic procedures.

CONCLUSIONS

CPNL often presents a diagnostic dilemma. Adopting a stepwise diagnostic strategy facilitates the identification of underlying etiologies, which is crucial for recognizing diseases and administering pruritus-specific pharmacotherapy.

Chronische Prurigo

Die chronische Prurigo (CPG) ist eine neuroinflammatorische Dermatose, die durch langanhaltenden Pruritus von mehr als 6 Wochen, pruriginösen Hautläsionen und wiederholtem Kratzen gekennzeichnet ist. Patienten mit CPG leiden unter erheblichen psychischen Belastungen und deutlich spürbarer Beeinträchtigung ihrer Lebensqualität. Der am häufigsten vorkommende Subtyp der CPG ist die chronisch noduläre Prurigo (CNPG; auch Prurigo nodularis genannt).

Neben den klinischen Merkmalen der CPG und der Krankheitslast bietet dieser CME‐Artikel einen Überblick über die bedeutenden Fortschritte im Verständnis der Pathophysiologie, einschließlich der damit verbundenen therapeutischen Optionen der CPG. Dupilumab ist die erste zugelassene Therapie für die moderate und schwere CNPG, die bisher von der Europäischen Arzneimittelagentur (EMA) und der US‐amerikanischen Food & Drug Administration (FDA) zugelassen wurde. Des Weiteren werden weitere Wirkstoffe hervorgehoben, die derzeit in klinischen, randomisierten, placebokontrollierten Phase‐II‐ und Phase‐III‐Studien untersucht werden. Dazu gehören Biologika wie Nemolizumab (Anti‐IL‐31‐RA‐mAk), Vixarelimab/KPL‐716 (Anti‐Oncostatin‐M Rezeptor β‐mAk) und Barzolvolimab/CDX‐0159 (Anti‐KIT‐mAK), Januskinase‐Inhibitoren wie Povorcitinib/INCB054707 und Abrocitinib sowie Opiodmodulatoren wie Nalbuphin.

Chronic Prurigo

Chronic prurigo (CPG) is a neuroinflammatory dermatosis characterized by prolonged pruritus lasting more than 6 weeks, pruriginous skin lesions, and repeated scratching. Patients with CPG suffer significantly from psychological distress and a marked impairment in their quality of life. The most common subtype of CPG is chronic nodular prurigo (CNPG, also called prurigo nodularis). In addition to the clinical features of CPG and the burden of disease, this CME article provides an overview of the significant advances in understanding the pathophysiology, including the associated therapeutic options for CPG. Dupilumab is the first approved therapy for moderate and severe CNPG to date from the European Medicines Agency (EMA) and the US Food & Drug Administration (FDA). It also highlights other agents currently being studied in Phase II and Phase III clinical, randomized, placebo-controlled trials. These include biologics such as nemolizumab (anti-IL-31-RA-mAb), vixarelimab/KPL-716 (anti-Oncostatin-M receptor β-mAb), and barzolvolimab/CDX-0159 (anti-KIT-mAb), as well as Janus kinase inhibitors such as povorcitinib/INCB054707 and abrocitinib, and opioid modulators such as nalbuphine.

Emerging trends and hotspots of the itch research: A bibliometric and visualized analysis

AIMS

Itch, a common uncomfortable sensory experience, occurs frequently in inflammatory or allergic disorders. In recent years, with the discovery of itch-specific pathways in the peripheral and central nervous system, the association between immunology and neural pathways has gradually emerged as the main mechanism of itch. Although many studies have been conducted on itch, no bibliometric analysis study focusing on this topic has been conducted. This study aimed to explore the research hotspots and trends in the itch field from a bibliometric perspective.

METHODS

Publications relevant to itch, published from 2003 to 2022, were retrieved from the Science Citation Index-Expanded of Web of Science Core Collection. Publications were critically reviewed and analyzed with CiteSpace software, Vosviewer, and the bibliometric online analysis platform. Visual maps were conducted in terms of annual production, collaborating countries or institutions, productive authors, core journals, co-cited references, and keyword bursts.

RESULTS

2395 articles on itch that met our criteria were identified and the quantity of publications has been increasing rapidly since 2012. The USA was the most influential country. University Hospital Münster was the institution with the most publications. Gil Yosipovitch was the most prolific author. Atopic dermatitis (AD), intradermal serotonin, chronic pruritus, mechanical itch, gastrin-releasing peptide, substance p, interleukin-31 receptor, histamine-induced itch, bile acid, scratching behavior, and h-4 receptor were the top 11 clusters in co-citation cluster analysis. Keyword burst analysis suggested that treatment, inflammation, and AD are current research hotspots.

CONCLUSION

Global publications on itch research have increased steadily and rapidly over the past 20 years. Inflammation and AD are current research hotspots. The neuroimmunological and neuroinflammatory mechanisms of itch, as well as clinical assessment methods and therapeutic targets, will be novel research directions in the future. This study provides guidance for further itch research.

Chronic Prurigo Including Prurigo Nodularis: New Insights and Treatments

Chronic prurigo (CPG) is a neuroinflammatory, fibrotic dermatosis that is defined by the presence of chronic pruritus (itch lasting longer than 6 weeks), scratch-associated pruriginous skin lesions and history of repeated scratching. Patients with CPG experience a significant psychological burden and a notable impairment in their quality of life. Chronic prurigo of nodular type (CNPG; synonym: prurigo nodularis) represents the most common subtype of CPG. As CNPG is representative for all CPG subtypes, we refer in this review to both CNPG and CPG. We provide an overview of the clinical characteristics and assessment of CPG, the burden of disease and the underlying pathophysiology including associated therapeutic targets. The information provided results from a PubMed search for the latest publications and a database search for current clinical trials (ClinicalTrials.gov, EU Clinical Trials Register [European Medicines Agency]; using the following terms or combinations of terms: 'chronic prurigo', 'prurigo', 'prurigo nodularis', 'pathophysiology', 'therapy', 'biologics', 'treatment'). Dupilumab is the first authorized systemic therapy by the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA) for CNPG to date. Topical and systemic agents that are currently under investigation in clinical randomized, placebo-controlled phase II and III trials such as biologics (e.g., nemolizumab, vixarelimab/KPL-716, barzolvolimab/CDX-0159), small molecules (ruxolitinib cream, povorcitinib/INCB054707, abrocitinib) and the opioid modulator nalbuphine are highlighted. In the last past 15 years, several milestones have been reached regarding the disease understanding of CPG such as first transcriptomic analysis, first terminology, first guideline, and first therapy approval in 2022, which contributed to improved medical care of affected patients. The broad range of identified targets, current case observations and initiated trials offers the possibility of more drug approvals in the near future.

S. aureus drives itch and scratch-induced skin damage through a V8 protease-PAR1 axis

Itch is an unpleasant sensation that evokes a desire to scratch. The skin barrier is constantly exposed to microbes and their products. However, the role of microbes in itch generation is unknown. Here, we show that Staphylococcus aureus, a bacterial pathogen associated with itchy skin diseases, directly activates pruriceptor sensory neurons to drive itch. Epicutaneous S. aureus exposure causes robust itch and scratch-induced damage. By testing multiple isogenic bacterial mutants for virulence factors, we identify the S. aureus serine protease V8 as a critical mediator in evoking spontaneous itch and alloknesis. V8 cleaves proteinase-activated receptor 1 (PAR1) on mouse and human sensory neurons. Targeting PAR1 through genetic deficiency, small interfering RNA (siRNA) knockdown, or pharmacological blockade decreases itch and skin damage caused by V8 and S. aureus exposure. Thus, we identify a mechanism of action for a pruritogenic bacterial factor and demonstrate the potential of inhibiting V8-PAR1 signaling to treat itch.

[Management of pruritus in the elderly]

BACKGROUND

Chronic pruritus (CP), a frequent (20.3%) symptom in the elderly, increases with age. It has a significant impact on the quality of life, ranking among the 50 most burdensome diseases worldwide (Global Burden of Disease Study).

OBJECTIVES

The aim is to provide an overview of the symptom CP in the elderly and to improve differentiation of underlying conditions and management of this entity.

MATERIALS AND METHODS

A literature search in PubMed was performed, using the terms 'pruritus', 'elderly' and 'gerontodermatology'.

RESULTS

The main causes of CP in the elderly are the physiologic aging process (xerosis cutis, immunosenescence, neuropathy), the increase in potentially pruritic diseases with increasing age (diabetes mellitus, chronic renal failure), and polypharmacy. Therapeutic options relate to causes, severity of pruritus, and individual patient factors (multimorbidity, impaired organ function). The recently updated S2k guideline 'Diagnosis and therapy of chronic pruritus' is helpful.

CONCLUSION

CP in the elderly is challenging for both patients and physicians. Not only the difficulty of identifying the underlying cause, but the complexity of treatment and its tolerability and practicability determines these patients' further burden.

Clinical aspects and management of chronic itch

Chronic pruritus (CP) (ie, itch that persists for more than 6 weeks) poses significant challenges to patients' health and quality of life. It is a common reason for visits to dermatologists and general practitioners and can be caused by a range of conditions, including systemic diseases such as chronic kidney disease or liver diseases, malignancies, neuropathic conditions, and dermatoses such as atopic dermatitis. CP often does not develop in parallel with the course of the disease and can become an entity of its own, which must be treated with antipruritic drugs, even if the underlying cause is already under therapy. Depending on the etiology of CP, different pathways in the pathogenesis have been analyzed recently, following which new treatments have been developed and tested in randomized controlled trials. This article discusses the recent results of these studies and highlights how best to manage health care for patients with CP.

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.

GABAergic neurons in the ventral lateral geniculate nucleus and intergeniculate leaflet modulate itch processing in mice

Itch and pain are two closely related sensations that receiving similar encodings at multiple levels. Accumulated evidences suggest that activation of the ventral lateral geniculate nucleus and intergeniculate leaflet (vLGN/IGL)-to-lateral and ventrolateral periaqueductal gray (l/vlPAG) projections mediates the antinociceptive effects of bright light therapy. Clinical study showed that bright light therapy may ameliorate cholestasis-induced pruritus. However, the underlying mechanism and whether this circuit participates in itch modulation remains unclear. In this study, chloroquine and histamine were utilized to induce acute itch models in mice. Neuronal activities in vLGN/IGL nucleus were evaluated with c-fos immunostaining as well as fiber photometry. Optogenetic manipulations were performed to activate or inhibit GABAergic neurons in the vLGN/IGL nucleus. Our results showed that the expressions of c-fos in vLGN/IGL were significantly increased upon both chloroquine- and histamine-induced acute itch stimuli. GABAergic neurons in vLGN/IGL were activated during histamine and chloroquine-induced scratching. Optogenetic activation of the vLGN/IGL GABAergic neurons exerts antipruritic effect, while inhibiting these neurons exerts pruritic effect. Our results provide evidence that GABAergic neurons in vLGN/IGL nucleus might play a crucial role in modulating itch, which may provide clue for application of bright light as an antipruritic treatment in clinic.

Introduction of a Specific Dermatological Rehabilitation Programme for Patients with Chronic Pruritus: A Pilot Study

Chronic pruritus is a common symptom, associated with several severe medical conditions, great psychological burden, and reduced quality of life. It also poses socio-economic challenges concerning patients' work loss and healthcare costs. In Germany, medical rehabilitation programmes represent an integral part of the medical care of patients with chronic inflammatory skin diseases. However, such programmes play only a rudimentary role in the treatment of other dermatological diseases, such as dermatological oncology, genetic skin diseases, and chronic pruritus. Therefore, a specific antipruritic dermatological rehabilitation programme was developed in cooperation between the Department of Dermatology of the Medical Rehabilitation Center Bad Bentheim and the Center for Chronic Pruritus of the University Hospital of Muenster, Germany. This prospective study compared short-term patient-reported outcomes (n = 121) at the beginning and end of the rehabilitation programme. The majority of subjects had chronic pruritus on primary diseased, inflamed skin. Significant improvements in pruritus intensity (p ≤ 0.001), quality of life (p ≤ 0.001), anxiety symptoms (p ≤ 0.001) and depression (p ≤ 0.001), as well as an overall patient-relevant benefit (Patient Benefit Index 2.6 ± 1.06) and treatment-related patients' satisfaction, were shown. This suggests that implementation of this standardized rehabilitation programme for treatment of patients with chronic pruritus was successful.

Biological and psychosocial factors associated with the persistence of pruritus symptoms: protocol for a prospective, exploratory observational study in Germany (individual project of the Interdisciplinary SOMACROSS Research Unit [RU 5211])

INTRODUCTION

Chronic pruritus (CP) is a symptom of dermatologic, neurologic, systemic and psychosomatic diseases. CP has a prevalence of ~20% in the general population and is therefore a significant burden on society, but the transition from acute pruritus to CP is not well understood. It probably involves interactions between biological and psychosocial factors and pruritus-specific risk factors as well as mechanisms shared with other persistent somatic symptoms addressed in other projects of the SOMACROSS Research Unit (RU). Here we aim to identify psychosocial and biological factors and their interactions which might be associated with the persistence of CP with and without immunologic/inflammatory origin, that is, atopic dermatitis and pruritus on non-inflamed skin. We expect that psychosocial factors relevant to the persistence of symptoms such as fatigue and pain may also show associations to CP.

METHODS AND ANALYSIS

In this prospective, exploratory observational study situated in Germany, three cohorts of 40 patients each with acute exacerbation of atopic dermatitis and chronic atopic dermatitis and 40 CP patients with unaffected skin will be recruited for a comprehensive translational investigation including pruritus-specific and the shared psychosocial assessments of the RU SOMACROSS. Pruritus-specific measures will include questionnaires, quantitative sensory testing, cutaneous nerve fibre morphology, skin barrier morphology, epidermal metabolism and pruritogen blood levels. Within 1 year, patients and 80 age-matched and sex-matched healthy controls will be examined at three time points, allowing cross-sectional comparison and a longitudinal investigation of predictive outcome factors in patients under treatment according to existing guidelines.

ETHICS AND DISSEMINATION

The study has been approved by the ethics committees of Hamburg (2020-10200-BO-ff) and Münster (2020-676 f-S), Germany. All participants are required to provide written informed consent. Findings will be disseminated through peer-reviewed publications, scientific conferences and involvement of relevant stakeholders, patients and the lay public.

TRIAL REGISTRATION NUMBER

DRKS00026646.

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.

Efficacy and safety of oral nalbuphine extended release in prurigo nodularis: results of a phase 2 randomized controlled trial with an open-label extension phase

BACKGROUND

Treatment of prurigo nodularis (PN) is challenging and new treatment options are needed.

OBJECTIVE

To evaluate the efficacy and safety of two oral doses of the kappa opioid agonist and mu opioid antagonist nalbuphine extended release (NAL-ER) tablets in a phase 2, multicentre, randomized, double-blind, placebo-controlled trial with an open-label, 50-week extension phase.

METHODS

Subjects with moderate-to-severe PN were randomized to NAL-ER 81 mg (NAL-ER81) or 162 mg (NAL-ER162) tablets twice-daily or placebo for 8 weeks of stable dosing following a 2-week titration period. Subjects completing Week 10 with a Worst Itch Numerical Rating Scale (WI-NRS) score ≥5 at the time of rollover (or during the observation period) were eligible for open-label treatment.

RESULTS

Of 63 randomized subjects, 62 were treated and comprised the modified intent-to-treat population (MITT), 50 completed 10 weeks of treatment. In the MITT analysis, 8 subjects (44.4%) treated with NAL-ER162 (P = 0.32) and 6 (27.3%) treated with NAL-ER81 (P = 0.78) achieved ≥30% reduction from baseline in 7-day WI-NRS at Week 10 (primary efficacy endpoint) vs. 8 (36.4%) in the placebo group. Itch reduction was significant among 8/12 (66.7%) subjects completing Week 10 treated with NAL-ER162 vs. placebo (8/20, 40.0%; P = 0.03). Additionally, 6 subjects (33.3%) treated with NAL-ER162 and 3 (13.6%) treated with NAL-ER81 achieved ≥50% reduction from baseline in 7-day WI-NRS at Week 10 (coprimary endpoint). Extended open-label treatment was associated with further improvements in itch reduction and favourable changes in PN lesion activity as assessed by Prurigo Activity Score. Adverse events occurred predominantly during dose titration and were of mild-to-moderate severity. The safety profile did not change with extended open-label treatment.

CONCLUSION

In adult subjects with PN, oral treatment with NAL-ER 162 mg twice daily provided measurable anti-pruritic efficacy in subjects completing ≥10 weeks of treatment and was well tolerated (ClinicalTrials.gov: NCT02174419).

Assessment of the anxiety and depression among patients with idiopathic pruritus ani

Introduction

Pruritus ani is an unpleasant sensation that leads to scratching of the skin around the anus. It is a common symptom due to many systemic, dermatological, and proctological conditions. In the absence of evident organic origin of a disease, pruritus may be related to mental disorders as well as personality disorders.

Aim

To assess the influence of pruritus on anxiety and depression in these patients.

Material and methods

The study involved 60 patients complaining of persistent pruritus ani. The study included people in which pruritus for organic reasons was ruled out. Tests were carried out to assess the level of depression and anxiety disorders. In addition, patients were asked to fill in the Questionnaire for the Descriptive Assessment of Pruritus and the 4-Item Itch Questionnaire by prof. Jacek Szepietowski.

Results

The cause of pruritus ani in the study groups has been shown to have a significant influence on the level of depressive symptoms. There was no such relationship for anxiety disorders. In the study group, there was no correlation of depressive-anxiety symptoms with the level of pruritus intensity and the frequency of pruritus.

Conclusions

The presented data reveal the negative effect of pruritus ani on the psychological functioning of patients. Pruritus ani is characterized by moderate intensity of pruritus, but has a significant influence on the aggravation of depressive symptoms. It is important to look for the causes of this symptom, which can help to eliminate its intensity, improve the patients’ mood, and thus improve their quality of life.

Cognitive Impairment in Inpatients with Prurigo Nodularis and Psychiatric Comorbidities

BACKGROUND

Prurigo nodularis (PN) is a chronic refractory itchy dermatosis. Although psychiatric comorbidity is known, research in cognitive impairment is lacking. We evaluated the occurrence and types of cognitive impairment in a series of inpatients with PN.

METHODS

This was a retrospective chart review of all the patients with PN admitted to a referral neurological institute from September 2018 to March 2021. Any neurological and psychiatric disorder, along with neuroactive drugs taken, were concomitantly assessed.

RESULTS

A total of 16 patients with PN (median age: 70 years, two males) were selected from a total of 1806 hospital admissions. Most of them had a neurodegenerative cognitive disorder, from mild cognitive impairment (8) to Alzheimer's disease (1), followed by mixed disorder (degenerative and vascular) in six and vascular dementia in one. Comorbid psychiatric diseases (anxiety and depression) were more common than either individual condition, followed by bipolar disorder, whereas two patients did not show psychiatric manifestations. Most patients were on combined treatment with benzodiazepines and antidepressants.

CONCLUSION

Cognitive impairment can be observed in PN. In addition to screening for psychiatric comorbidity and initiating appropriate treatment or referral, clinicians may also consider the presence of cognitive impairment in PN of both degenerative and vascular origin.

Cognitive Impairment in Inpatients with Prurigo Nodularis and Psychiatric Comorbidities

BACKGROUND

Prurigo nodularis (PN) is a chronic refractory itchy dermatosis. Although psychiatric comorbidity is known, research in cognitive impairment is lacking. We evaluated the occurrence and types of cognitive impairment in a series of inpatients with PN.

METHODS

This was a retrospective chart review of all the patients with PN admitted to a referral neurological institute from September 2018 to March 2021. Any neurological and psychiatric disorder, along with neuroactive drugs taken, were concomitantly assessed.

RESULTS

A total of 16 patients with PN (median age: 70 years, two males) were selected from a total of 1806 hospital admissions. Most of them had a neurodegenerative cognitive disorder, from mild cognitive impairment (8) to Alzheimer's disease (1), followed by mixed disorder (degenerative and vascular) in six and vascular dementia in one. Comorbid psychiatric diseases (anxiety and depression) were more common than either individual condition, followed by bipolar disorder, whereas two patients did not show psychiatric manifestations. Most patients were on combined treatment with benzodiazepines and antidepressants.

CONCLUSION

Cognitive impairment can be observed in PN. In addition to screening for psychiatric comorbidity and initiating appropriate treatment or referral, clinicians may also consider the presence of cognitive impairment in PN of both degenerative and vascular origin.

Association between chronic pruritus, depression, and insomnia: A cross-sectional study

Background

Skin diseases that cause chronic pruritus can have negative effects on a patient's quality of life.

Objective

We evaluated the associations between chronic pruritus and psychological conditions including insomnia and depression.

Methods

This study included responses from 91 participants with chronic pruritus (response rate: 74.6%). A survey including questionnaires regarding data on demographic characteristics, intensity of pruritus using the visual analog scale (VAS) and the 4-item itch questionnaire, and the degrees of insomnia and depression measured by the Insomnia Severity Index and Beck Depression Inventory, respectively.

Results

Patients with symptoms of insomnia or depression had significantly more intense pruritus than patients without psychological symptoms (insomnia, VAS median [interquartile range]: 7.0 [5.0-8.25] vs. 5.0 [3.0-7.5]; depression, VAS median [interquartile range]: 7.5 [5.0-8.25] vs. 5.0 [3.0-7.0]). Multivariable analyses revealed that patients with moderate to severe pruritus were more likely to have depression than those with mild pruritus (odds ratio: 10.95; 95% confidence interval: 2.24-53.06). There were no differences in the severity of insomnia and depression among skin diseases.

Limitations

This study had a cross-sectional design and limited generalizability.

Conclusion

Chronic pruritus is significantly associated with insomnia and depression, regardless of the etiology.

Affective Touch Reduces Electrically Induced Itch Experience

Introduction: Itch is a common symptom in dermatologic and other diseases and can have a severe impact on quality of life and mental health. As a proportion of patients with itch-symptoms is resistant to commonly used anti-histamine treatments, development of new treatments is desirable. Past research on pain, itch and affective touch (i.e. slow, gentle stroking of the skin activating C-tactile fibers) revealed an inhibitory relationship between affective touch and pain and between pain and itch. Given the overlap in neural processing between these three sensory submodalities, a possible interaction between affective touch and itch might be expected. This study investigated whether there is a relationship between itch and affective touch, and if so, whether affective touch inhibits itch.

Methodology: Itch was electrically induced with the use of electrodes that were placed at the ventral side of the wrist of 61 participants. A within-subject design was conducted with two conditions. An experimental -affective touch- condition (stroking the forearm with a soft brush at 3 cm/s) and a control -non-affective touch- condition (stroking the forearm with a soft brush at 18 cm/s). Touch was applied on the dorsal side of the forearm, the same arm as were the electrodes were placed. For each condition itch was induced for 20 min, with every 2 min a VAS-scale measurement of the level of experienced itch.

Results: Both types of touch reduced the experienced itch compared to baseline (p < 0.01, partial η² = 0.67). However, affective touch had an additional significant relieving effect compared to non-affective touch (p = 0.03, partial η²= 0.08). The alleviation of itch started after 2 min of stroking and continued to increase up till 6 min, where after the relieving effect stabilized but still persisted.

Conclusion: This finding suggest that affective touch, as with acute pain, has a relieving effect on electrically induced itch.

Pruriplastic Itch-A Novel Pathogenic Concept in Chronic Pruritus

The International Association for the Study of Pain (IASP) defined three descriptors for pain: nociceptive pain is “pain that arises from actual or threatened damage to non neural tissue and is due to the activation of nociceptors”; neuropathic pain is “pain caused by a lesion or disease of the somatosensory nervous system”; and nociplastic pain is “pain that arises from altered nociception despite no clear evidence of actual or threatened tissue damage causing the activation of peripheral nociceptors or evidence for disease or lesion of the somatosensory system causing the pain.” Based on clinical and pathophysiological arguments, a similar definition of “pruriplastic pruritus” should be made. Pruriplastic pruritus would include psychogenic pruritus, as well as some cases of pruritus ani, vulvar pruritus, sensitive skin or other poorly understood cases of pruritus. This new descriptor of itch could serve as systematic screening for altered pruriceptive function in patients who suffer from chronic itch and it may also help in defining better tailored treatment by identifying patients who are likely to respond better to centrally rather than to peripherally targeted therapies.

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.

The burden in chronic prurigo: patients with chronic prurigo suffer more than patients with chronic pruritus on non-lesional skin: A comparative, retrospective, explorative statistical analysis of 4,484 patients in a real-world cohort

BACKGROUND

Chronic prurigo (CPG) is known as a high burdensome disease characterized by severe pruritus and multiple pruriginous lesions. Interestingly, the disease-specific burden is not well established and there are no data which compare the impact of CPG with chronic pruritus (CP) on non-lesional skin (CP-NL).

OBJECTIVES

To address this issue, we analysed datasets from 4484 patients with either CPG or CP-NL.

METHODS

Demographic medical data and additional information collected by validated patient reported outcome tools were analysed. The visual analogue scale and numerical rating scale (NRS) were used for assessing the pruritus intensity, the ItchyQoL for patients' quality of life, the Hospital Anxiety and Depression Scale and the Patient Needs Questionnaire' as a part of Patient Benefit Index for Pruritus for measuring the importance of 27 patient needs in terms of treatment goals. The Neuroderm questionnaire was used to assess the history of pruritus characteristics and the impact on sleep.

RESULTS

Patients with CPG suffered longer and with a higher intensity from pruritus [NRS worst the last 24 h, CPG 6.0 (4.0;8.0) vs. CP-NL 3.0 (5.0;7.0), P < 0.001]. In them, pruritus occurred more often and the whole day and night which led to more loss in sleeping hours [CPG 3.0 h (2.0;4.0) vs. CP-NL 2.0 h (1.0;4.0), P < 0.001]. Patients with CPG showed higher scores for depression [HADS-D, CPG 6.0 (3.0;10.0) vs. CP-NL 5.0 (2.0;8.0), P < 0.001], more impaired quality of life [ItchyQol; CPG: 72.6 (61.6;83.6) vs. CP-NL 59.4 (48.4;70.4), P < 0.001] and higher weighted needs in the predefined treatment goals.

DISCUSSION

Not only the presence of severe pruritus and pruriginous lesions but also sleep disorders and other mental symptoms may contribute to a higher burden in patients with CPG when compared with patients with CP-NL.

Health-Related QOL and Economic Burden of Chronic Pruritus

Chronic pruritus (CP) has considerable implications for QOL. However, its impact on health-related QOL and economic burden is not fully characterized. We administered a cross-sectional survey on 132 patients with CP using the Health Utilities Index Mark 3 instrument. Normative data from healthy adults (n = 4,187) were obtained from the Joint Canada/US Survey of Health. Quality-adjusted life-year loss and economic costs were estimated on the basis of Health Utilities Index Mark 3 scores of patients with CP versus controls. Patients with CP had lower overall health performance than the control (0.56 ± 0.03 vs. 0.86 ± 0.003, P < 0.001). In multivariable regression, CP was associated with worse overall health performance (coefficient = -0.30, 95% confidence interval = -0.33 to -0.27), most accentuated in the domains of pain (coefficient = -0.24, confidence interval = -0.28 to -0.21) and emotion (coefficient = -0.11, confidence interval = -0.13 to -0.10). The reduced Health Utilities Index Mark 3 score correlated with 5.5 average lifetime quality-adjusted life-years lost per patient. Using conservative estimates for willingness to pay, the quality-adjusted life-year loss translated to an individual lifetime economic burden of $274,921 and a societal burden of $88.8 billion. CP is associated with significant QOL impairment. The economic burden of CP highlights the necessity for further research into management options.

Clinical validation and utility of Chinese Eppendorf Itch Questionnaire in adults with chronic pruritus symptoms

BACKGROUND

Pruritus, or itch, is a prevalent symptom causing profound health burden in many dermatological and non-dermatological disorders. Several itch questionnaires have been created to assess itch. Particularly, Eppendorf Itch Questionnaire (EIQ) is widely accepted since it encompasses various aspects of itch, including intensity, affects, coping behavior, and motivation to scratch.

METHODS

In a cross-sectional survey, we examined the validity, reliability and clinical utility of Traditional Chinese EIQ.

RESULTS

We administered the consensus version to 128 adults (median: 48.5 years, interquartile range [IQR]: 39-63) with active itch for more than 6 weeks at the Outpatient Clinics of three medical centers in Taiwan. Clinical diagnoses included psoriasis (N = 82), xerosis (N = 34), or other dermatitis (N = 12). Cronbach's alpha for each EIQ scale ranged 0.82-0.98, suggesting good to excellent internal consistency and reliability. Three EIQ scales significantly correlated with visual analogue scale (VAS) for itch intensity (P ≤ 0.001 for median test), supporting for its concurrent validity. None of EIQ scale was statistically correlated with Psoriasis Area Severity Index (PASI) scores in psoriasis patients, confirming its discriminant validity. Moreover, patients of different diagnoses had distinct responses to the multi-scale EIQ index, affording it a better clinical test (area-under-the-ROC curve [AUC]: 0.76, 95% CI: 0.63-0.90) than VAS alone (AUC: 0.42, 95%CI: 0.24-0.59) in distinguishing dermatitis/eczema-related itch from psoriasis or xerosis-related itch.

CONCLUSION

We demonstrated the reliability and validity of Chinese EIQ in adult patients with chronic itch at the outpatient setting. The study also revealed the diversified aspects of itch across patients with various dermatoses.

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.

Self-reported generalised pruritus among community-dwelling older adults in Malaysia

Background

The ageing skin is more susceptible to pruritic dermatoses, which are associated with adverse psychosocial effects and reduced quality of life among older adults. This cross-sectional study aimed to identify the burden of pruritus and factors associated with its presence and severity among older adults recruited to the Malaysian Elders Longitudinal Research study.

Methods

Seven hundred seventy individuals aged 55 years (lower age limit) and above were interviewed as to whether they experienced pruritus during the preceding week and the locations involved if present. The association between generalised pruritus, sleep quality, and major systemic risk factors were explored.

Results

5.97% of respondents reported generalised pruritus. Generalised pruritus was associated with poorer sleep quality, with Pittsburgh Sleep Quality Index score above 6. Mean haemoglobin level was lower in subjects with generalised pruritus (13.14 g/dL) but there was no significant difference in the frequency of generalised pruritus and severe generalized pruritus between subjects with clinically defined anaemia. Also, there were no significant associations between other major systemic risk factors and generalised pruritus in this population-based study. There was no association between generalised pruritus with depression, anxiety or stress.

Conclusion

The negative effect of pruritus on sleep quality suggests a possible deleterious effect of pruritus on health and quality of life. Further prospective research on the longer-term effects of pruritus on health status is now warranted.

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Keratin 17 is induced in prurigo nodularis lesions

Prurigo nodularis (PN) is a highly pruritic chronic inflammatory dermatosis with unknown pathogenesis. It is characterized by the existence of many hyperkeratotic, erosive papules and nodules, and the development of lesions may be associated with hyperproliferation and aberrant differentiation of keratinocytes. Keratin 17 (K17) is overexpressed selectively in human proliferative skin diseases, promoting keratinocyte proliferation not found in normal epidermis. In this study, we investigated the mRNA levels and protein levels of K17 in lesional and perilesional skin using quantitative real-time polymerase chain reaction and western blot. We demonstrate that K17 is induced in lesional and perilesional skin in PN. The mRNA expression level of K17 was upregulated in PN lesions (P < 0.01), with multifold changes in the PN lesion (normalized to glyceraldehyde-3-phosphate dehydrogenase as the housekeeping gene) showing a median positive correlation with PRUNOSI (P < 0.05). The protein level of K17 was also markedly increased in PN lesions (P < 0.01). In conclusion, K17 is highly induced in PN lesions, which may contribute to the proliferation of keratinocytes and the pathogenesis of PN.

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.

Association of prurigo nodularis and lichen simplex chronicus with hospitalization for mental health disorders in US adults

Prurigo nodularis (PN) and lichen simplex chronicus (LSC) are debilitating chronic pruritic diseases that can lead to and be exacerbated by psychosocial distress. However, little is known about the mental health (MH) comorbidities of PN/LSC. We sought to evaluate the likelihood and cost-burden of MH comorbidities and emergencies associated with PN/LSC. Data were examined from the 2002-2012 Nationwide Inpatient Sample, including a representative ~ 20% sample of US hospitalizations (n = 87,053,155 admissions). Inpatients with vs. without PN/LSC had higher odds of MH disorders overall (39.4% vs. 20.0%; adjusted odds ratio [95% confidence interval, CI] 2.26 [2.13-2.41]) and in all 15 individual MH disorders examined. Inpatients with vs. without PN/LSC were more likely to be admitted with a primary diagnosis of a MH disorder (4.5% vs. 2.2%; 2.16 [1.91-2.45]), particularly developmental, psychotic, and mood disorders, history of MH disorders or substance abuse, and cognitive disorders. PN/LSC were associated with prolonged inpatient length of stay, and an excess $0.69 million in inpatient costs of care indirectly related to hospitalization for MH disorders. In conclusion, inpatients with PN/LSC had increased likelihood of comorbid MH disorders and emergencies requiring hospitalization. Optimized approaches are needed for screening and managing MH comorbidities in PN/LSC.

Acquired perforating dermatosis: clinicopathologic study of a 10-year period at a tertiary teaching hospital

BACKGROUND

Acquired perforating dermatosis (APD) comprises an uncommon group of skin disorders that develop in adulthood in association with systemic diseases. The aim of this study was to characterize clinicopathologic features and treatment outcomes in a series of patients diagnosed with APD.

METHODS

Retrospective study of all patients diagnosed with an APD over a 10-year period (2009-2018) at a tertiary teaching hospital in Lisbon, Portugal.

RESULTS

Fifty-seven patients with APD were identified. Thirty-five patients presented lesions in multiple anatomic areas (61.4%), and the lower limbs were the most common location. Forty-six patients reported pruritus (80.7%), which was classified as severe in 21 of them (36.8%). An underlying systemic disease was identified in 53 patients (93.0%). Diabetes mellitus (DM) and chronic kidney disease (CKD) were the most common associated systemic diseases, but psychiatric disorders, malignancies, and chronic infections were present in a significant number of patients. The combination of topical steroids with antihistamines was the most prescribed initial treatment, but only 37.8% of the patients had a complete response. Acitretin, systemic steroids, and phototherapy were the treatments associated with the best outcome.

CONCLUSION

Acquired perforating dermatosis can be associated with many systemic disorders that have pruritus as a common factor. Chronic viral infections and an occult malignancy should be sought, particularly in the absence of DM and CKD. The management of APD is challenging and is best achieved with the control of the underlying systemic diseases.

Management of Itch in the Elderly: A Review

Chronic itch is common in the elderly patient and may be caused by a variety of known dermatologic and non-dermatologic conditions and can have a significant effect on quality of life. Age-related changes in barrier function, immunosenescence, and neuronal changes and neuropathies are common predisposing factors to chronic itch in this age group. Certain primary dermatologic conditions are more common in the elderly and can cause chronic itch. Also, co-morbid diseases particularly of the renal, hepatobiliary, or hematologic systems, psychologic conditions, or medications may contribute to chronic itch in this population. Thus, medical workup for an elderly patient with chronic itch requires special attention to the patient's medical history, current health status, and medications. Topical treatments and emollients may be recommended for elderly patients, with consideration of specific adverse effects and alternatives. Systemic medications pose a higher risk of adverse effects and many are contraindicated in the elderly for this reason. In addition, management in the elderly may be complicated by differential pharmacokinetics of medications, the presence of co-morbid health conditions, cognitive disorders, physical limitations, and polypharmacy. New and emerging treatment modalities hold promise for use in the elderly due to these special considerations.

Pain and Pruritus: a study of their similarities and differences

Pruritus is one of the most common dermatologic complaints and, as the most common dermatologic symptom, is a major contributor to frequent dermatology visits. Chronic pruritus mirrors another major medical condition faced by millions of Americans each year - chronic pain. In older literature, pain and pruritus were thought to have been conveyed by the same C fiber, and the proportion contributing to pruritus was just a small subset of this general fiber. Overall, pain and pruritus share many integral similarities. Although these sensations both initiate the body's awareness to injury, pain and itch may have evolved for sensing different damages such as a burrowing parasite or a noxious stimulus, respectively. This seems to have been validated through analyses of their pathophysiology, acute and chronic conditions, and treatment modalities. However, their symptoms and intrinsic mechanisms vary considerably. It is important to view pruritus in more of an overall, whole body experience, rather than just the sensory aspect. Future studies should investigate the psychological treatment of chronic pruritus, considering the immense similarities with its chronic pain counterpart.

Evaluation of Chronic Pruritus in Patients over Age 65 Who Admitted to Family Medicine Outpatient Clinic

Aim: This study aims to evaluate the hematologic values, multiple drug use, regions with pruritus, number of regions with pruritus, and systematic diseases of patients over age 65 with chronic pruritus. Methods: A detailed evaluation was made of the hematologic values, itchy regions, multiple drug use, and systematic diseases of 102 patients age 65 and older who presented to our Family Health Center within the past year. Results: When the patients were evaluated according to additional disease, 39 (38.2%) patients had one, and 63 (61.8%) patients had more than one additional disease. According to drug use, 36 (35.5%) patients were using one drug, 27 (26.5%) were using two different drugs, and 39 (38.2%) patients were using three or more different drugs. Number of itchy regions was found to have no significant impact on number of additional diseases. There was no significant difference in number of itchy regions according to number of different drugs used. Conclusion: A detailed hematologic, systematic disease, and multiple drug use assessment of patients ages 65 and older who presenting with chronic itching to Family Health centers could establish a general approach to elderly individuals with chronic pruritus.

Inpatient Burden of Prurigo Nodularis in the United States

Background: Although prurigo nodularis (PN) has a significant burden of disease, little is known about its epidemiology and disease burden within the United States. We describe the characteristics of hospitalized patients diagnosed with PN and assess the factors associated with hospitalization. Methods: We performed a cross-sectional study of the 2016 National Inpatient Sample, a representative sample of 20% of hospital discharges nationally. Results: Patients diagnosed with PN accounted for 3.7 inpatient visits per 100,000 discharges nationally in 2016. Patients with PN were more likely to be black (odds ratio (OR) 4.43, 95% CI (3.33–6.08), p < 0.001) or Asian (OR 3.44, 95% CI (1.39–5.08), p = 0.003) compared with white patients. Patients diagnosed with PN had both a longer length of hospital stay (mean ± SD, 6.51 ± 0.37 days vs. 4.62 ± 0.02 days, p < 0.001) and higher cost of care ($14,772 ± $964 vs. $11,728 ± $106, p < 0.001) compared with patients without PN. Patients with PN were significantly more likely to be admitted for HIV complications (OR 78.2, 95% CI (46.4–131.8), p < 0.001). PN contributes to increased inpatient cost of care and length of hospitalization. Conclusions: There are racial disparities associated with hospital admission of patients diagnosed with PN.

Can we use psychoactive drugs to treat pruritus?

Pruritus is a frequent complaint both in dermatology and general medicine. This burdensome symptom has a complex and multifactorial pathogenesis, with the key involvement of central nervous system in its development. Psychoactive drugs (psychopharmaceuticals) encompass several therapeutic groups utilized mainly in psychiatry. However, these drugs are occasionally used in dermatological practice and may contribute to alleviation of pruritus in a variety of cutaneous and extracutaneous disorders. This review article summarizes the role of H1-antihistamines, antidepressants, antipsychotics and antiepileptics in managing pruritus.

A Subpopulation of Amygdala Neurons Mediates the Affective Component of Itch

Itch consists of both sensory and affective components. For chronic itch patients, the affective component of itch affects both quality of life (leading to psychological comorbidities) and disease prognosis (by promoting scratching of itchy skin). We found that acute itch stimuli, such as histamine, induced anxiety-like behavior and increased activity (c-Fos expression) in the amygdala in adult male C57BL/6 mice. Itch stimuli also increased activity in projection areas to the amygdala, suggesting that these regions form a circuit for affective itch processing. Electrophysiological characterization of histamine-responsive amygdala neurons showed that this population was active on a behaviorally relevant timescale and partially overlapped with pain signaling. Selective optogenetic activation of histamine-responsive amygdala neurons in adult male and female Fos:CreER^T2;R26^Ai14 mice using the Targeted Recombination in Active Populations system enhanced both scratching and anxiety-like behavior. These results highlight the importance of itch-responsive amygdala neurons in modulating itch-related affect and behavior.SIGNIFICANCE STATEMENT The sensation of itch includes an affective component that leads to stress and anxiety in chronic itch patients. We investigated the neuronal basis of affective itch in mice, with a focus on the amygdala, the key brain region for the generation of anxiety. A subpopulation of amygdala neurons responded to itch stimuli such as histamine. Optogenetic activation of histamine-responsive amygdala neurons affected both scratching and anxiety-like behavior. Therefore, this population appears to be important for mediating the affective component of itch.

Chronic itch impairs mood and HPA axis function in mice: modulation by CRFR1 antagonist

Chronic itch is clinically correlated with the development of mood disorders such as anxiety and depression. Nonetheless, whether this relevance exists in rodents is unknown, and evidence demonstrating chronic itch can affect mood is lacking. The aim of this study is to characterize the affective consequences of chronic itch, and explore potential mechanisms and interventional strategy. We subjected mice to chronic itch by repetitive cutaneous treatment with acetone and diethylether followed by water (AEW) that models "dry skin." After 3 to 4 weeks AEW treatment, the mice developed behavioral phenotypes of anxiety and depression assessed by a battery of behavioral paradigms, such as light-dark box and forced swim test. These behavioral symptoms of mood disturbance were independent of cutaneous barrier disruption, but correlated well with the degree of the irritating itch sensation. Although AEW mice showed normal circadian hypothalamic-pituitary-adrenal (HPA) axis activity, their neuroendocrine functionality was dampened, including impaired endocrine stress responsivity, altered neuroendocrine-immune interaction, and blunted corticosterone response to both dexamethasone and CRF. Parameters of HPA functionality at the level of mRNA transcripts are altered in stress-related brain regions of AEW mice, implying an overdrive of central CRF system. Remarkably, chronic treatment of AEW mice with antalarmin, a CRFR1 antagonist, ameliorated both their mood impairment and stress axis dysfunction. This is the first evidence revealing mood impairment, HPA axis dysfunction, and potential therapeutic efficacy by CRFR1 antagonist in mice with chronic itch, thus providing a preclinical model to investigate the affective consequence of chronic itch and the underlying mechanisms.

Cross-European validation of the ItchyQoL in pruritic dermatoses

BACKGROUND

Chronic pruritus (CP) is a frequently occurring symptom in inflammatory dermatoses, causing a high burden and limitations to health-related quality of life (HRQoL).

OBJECTIVE

The ItchyQoL was developed to assess the impairment to HRQoL in patients with CP. However, it has only been validated in English and German. Here, we report the validation in several languages across Europe.

METHODS

After professional translation, the versions of ItchyQoL were digitized for use as a tablet application. Validation was performed in clinics for dermatology in Austria, France, Germany, Italy, Poland, Russia, Spain, Switzerland and Turkey.

RESULTS

Five hundred and thirty-five patients with either contact dermatitis, chronic prurigo - nodular type, psoriasis vulgaris, lichen planus or mycosis fungoides/Sézary syndrome and with CP ≥ 3 on the numerical rating scale were included. ItchyQoL showed a high level of consistency (Cronbach's-α, all: 0.95) and test-retest reliability (intraclass correlation: 0.91). It strongly correlated with the Dermatology Life Quality Index (r = 0.72, P < 0.001) and moderately correlated with itch intensity scales in the study population (visual analogue scale r = 0.46; numerical rating scale r = 0.51; verbal rating scale r = 0.51, for all: P < 0.001).

CONCLUSION

ItchyQoL is now also validated in French, Italian, Polish, Russian, Spanish and Turkish and can be used in clinical trials in countries speaking these languages.

Relations between a standardized experimental stressor and cutaneous sensory function in patients with chronic pruritus and healthy controls: an experimental case-control study

Background

While chronic pruritus (CP) is a frequent symptom, many aspects of its underlying pathophysiological mechanisms still need elucidation. Research on sensory cutaneous function and on the influence of stress has been conducted mainly in patients with atopic dermatitis but is lacking for patients with CP.

Objective

To assess whether a standardized social stressor influences cutaneous sensory function in patients with CP in comparison with healthy controls (HC).

Methods

Case–control study; 33 CP and 30 HC were submitted to the standardized quantitative sensory testing protocol before and after the Trier Social Stress Test and 1 h later. Intraepidermal nerve fibre density (IENFD) was determined.

Results

Mechanical pain sensitivity and mechanical detection thresholds were significantly higher in CP than in HC, and mechanical detection thresholds increased more in CP than in HC over the three measurements. In both groups, cold pain threshold increased and heat pain threshold decreased from before to after the stress test and remained constant 1 h later. Only in CP, almost all QST tests induced at least a small amount of pruritus, which was not significantly altered by the stress test. IENFD in pruritic skin was significantly reduced in CP when compared to healthy controls.

Conclusion

Peripheral thermal sensory function was not altered in CP despite reduced IENFD in lesional skin, but we could demonstrate central sensitization processes specifically in CP and influences of an acute stressor inducing more sensitivity to thermal pain in both groups.

Prurigo nodularis: a physician survey to evaluate current perceptions of its classification, clinical experience and unmet need

BACKGROUND

Prurigo nodularis (PN) is a chronic skin condition characterized by intensely pruritic, hyperkeratotic papulonodular lesions that dramatically impairs patients' quality of life. Management of the condition is challenging, and there is no approved therapy in the United States or in Europe.

OBJECTIVE

The key aim of this survey was to examine current perceptions of PN diagnosis and management among members of the European Academy of Dermatology and Venereology (EADV).

METHODS

The survey comprised 29 questions, including multiple choice and open responses, and was sent to clinicians via e-mail during December 2016. The survey results were collected and analysed.

RESULTS

Responses were received from 30 participants from 14 countries, of whom 22 (73.3%) were members of the EADV Task Force Pruritus. The majority (73.3%) considered PN to be a distinct condition, and the preferred description to explain the most common pathogenesis was 'chronic pruritus leading to chronic scratching' (80.0%). Pruritic nodules (n = 23/30, 76.7%) and scratching (n = 12/30, 40.0%) were the most common descriptors used to characterize PN. Most respondents (60.0%) reported seeing ≤5 unique PN patients per month, the majority of whom (68.8%) visited a physician ~2-4 times per year. PN patients reported to the respondents that they experienced persistent, severe pruritus, with a mean ± SD numeric rating scale score of 7.8 ± 1.2, lasting for >6 months in 82.3% of patients and >2 years in 51.0%. The most frequently prescribed therapies by survey respondents for PN symptoms were antihistamines (90.0%), antidepressants (90.0%), gabapentinoids (86.7%) and immunosuppressants (86.7%). Respondents agreed upon the need for new PN therapies (56.7%), revised PN classification and terminology (23.3%) and better understanding of PN pathophysiology (20.0%).

CONCLUSION

EADV Task Force Pruritus notes several challenges that must be met to improve symptoms and quality of life for patients with PN.

Itch and psyche: psychiatric aspects of pruritus

Itch, also referred to as pruritus, is an unpleasant cutaneous sensation provoking the desire to scratch. It is often an uncomfortable, subjective sensation responsible for decreased quality of life in a variety of psychodermatological conditions. Comorbid psychiatric conditions, including depression and anxiety, are frequently associated with itch and scratch cycle. The reciprocal and intricate relationship between the psyche and itch has been widely studied. The neurobiology of itch involves the complexity of specific mediators, itch-related neuronal pathways, and central processing of itch. The connection between itch and the psyche can be grouped under three headings: pruritic diseases with psychosocial sequelae, pruritic diseases aggravated by psychosocial factors, and psychiatric disorders causing pruritus. Itch and pain modulation go together in most circumstances and involve various substances including histamine, interleukins, protease-activated receptors, transient receptor potential receptors, opioids, and cannabinoids. The close interaction between keratinocytes and nerve endings modulating pain and itch also play a major role. Management of itch associated with its psychosomatic components is directed at an underlying cause and adopting a holistic approach to address not only dermatologic and somatosensory aspects, but also the cognitive, emotional, and psychosocial components. An integrated multidisciplinary team consisting of a dermatologist, psychiatrist, psychologist, and social worker is vital in addressing the multifaceted aspects of pruritus.