Diagnosis and Management of Chronic Pruritus: An Expert Consensus Review

Psychodermatology of Chronic Pruritus: An Overview of the Link Between Itch and Distress

Chronic pruritus (CP) is defined as an unpleasant sensation causing a desire to scratch and lasting > 6 weeks. It has a multifactorial etiology but is more frequently associated with chronic inflammatory dermatoses and systemic disorders. Psychogenic pruritus and neurological disorders are other less common etiologies, while, in some patients, it is idiopathic. CP appears to be processed by non-histaminergic pathway, contributing to its complexity and therapeutic challenge. Moreover, regardless of the etiology, it is multidimensional, including cognitive, motivational and affective components. There is a close link between psychological distress and pruritus, with particular clinical expression in chronic inflammatory dermatoses, involving the activation of the hypothalamic-pituitary-adrenal axis (and its cutaneous equivalent), the sympathetic nervous system, the release of hormones and peptides, the role of immune cells (T and B cells, macrophages) and immune-related cells in the skin (mast cells, dendritic cells and keratinocytes). Moreover, there is strong evidence that psychological factors influence the experience of pruritus. CP can also cause psychiatric disorders, including but not limited to anxiety and depression, and also lead to significant quality of life (QoL) impairment. Thereby, although a psychodermatological assessment should ideally be carried out in the context of a specific psychodermatology consultation, a brief mental health assessment could be part of the general dermatological approach to these patients. Considering that mental health, QoL and pruritus are closely linked, psychotherapeutic interventions and/or psychotropic drugs should thus be considered in some patients as an adjunct to the pharmacological treatment of CP.

Navigating Perinatal Challenges: A Comprehensive Review of Cholestasis of Pregnancy and Its Impact on Maternal and Fetal Health

Cholestasis of pregnancy (CP), or intrahepatic CP (ICP), represents a condition peculiar to pregnancy, marked by impaired bile acid flow and consequent accumulation in the maternal bloodstream. Primarily emerging in the third trimester, CP is linked with considerable risks to both the mother and fetus, including heightened incidences of preterm birth, fetal distress, and stillbirth, alongside maternal complications such as intense pruritus and liver dysfunction. Despite its clinical significance, the etiology of CP, which involves genetic, hormonal, and environmental factors, remains partially understood. This comprehensive review delves into the physiology and pathophysiology of CP, outlines its clinical manifestations and diagnostic criteria, and discusses the associated maternal and fetal complications. Furthermore, it evaluates current management strategies, prognostic implications, and potential long-term effects on maternal and child health. It also explores future research directions, emphasizing the need for advancements in understanding the pathophysiology of CP, developing novel therapeutic interventions, and improving risk stratification models. By offering a thorough overview of CP, this review aims to enhance clinical awareness, guide management practices, and identify areas requiring further investigation, ultimately contributing to better health outcomes for affected women and their babies.

Combination treatment of dupilumab with bortezomib in a patient with IgG kappa gammopathy of renal significance, uremic pruritus and chronic lichenoid dermatitis

Chronic pruritus (CP) is one of the most frequent symptoms among dermatological conditions, capable of reducing the quality of life (QoL). CP may be induced by atopic dermatitis or other dermatological and/or non-dermatological conditions. In this article, we report the case of a patient affected by generalized CP, characterised by multiple papulo-nodular and escoriatic lesions, developed after the onset of an immunoglobulin G (IgG) kappa monoclonal gammopathy of renal significance (MGRS), associated with renal insufficiency. Therefore, a combined treatment with dupilumab for CP and bortezomib for the hematologic malignancy was administered to the patient. The present case report highlights the efficacy of dupilumab for the treatment of CP. Moreover, no relevant side effects were recorded during the treatment in combination with other systemic biological drugs for other systemic pathologies.

Kappa opioid agonists in the treatment of itch: just scratching the surface?

Chronic pruritus is a debilitating condition affecting 23-44 million Americans. Recently, kappa opioid agonists (KOAs) have emerged as a novel class of potent antipruritic agents. In 2021, the Food and Drug Administration approved difelikefalin (Korsuva) for the treatment of moderate-to-severe pruritus associated with chronic kidney disease in adults undergoing hemodialysis. Difelikefalin is a potent, peripherally restricted KOA that is intravenously available. Although promising, difelikefalin is currently available as an intravenous composition only, limiting the scope of use. Oral formulations of difelikefalin did not meet the primary endpoint criteria in recent phase 2 clinical trials; however, additional clinical studies are ongoing. The future for KOAs in the treatment of pruritus is encouraging. Orally active pathway-biased KOAs, such as triazole 1.1, may serve as viable alternatives with broader applications. Extended-release compositions, such as the TP-2021 ProNeura subdermal implant, may circumvent the pharmacokinetic issues associated with peptide-based KOAs. Lastly, dual-acting kappa opioid receptor agonist/mu opioid receptor antagonists are orally bioavailable and may be useful in the treatment of various forms of chronic itch. In this review, we summarize the results of KOAs in clinical and preclinical trials and discuss future directions of drug development.

Reduced serum pyridoxine and 25-hydroxyvitamin D levels in adults with chronic pruritic dermatoses

Little is known about the role nutritional factors play in the pathogenesis of chronic pruritic dermatoses (CPD). In this study, we analyzed nutritional deficiencies in CPD patients compared to matched controls. We conducted a population-based study from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2006. The main outcomes of the study were laboratory data on serum vitamin levels in participants who answered affirmatively to the questionnaires on CPD as well as matched healthy controls. We identified 877 cases of CPD among 9817 adults in the US aged 20 to 59 years. These findings revealed a slightly higher percentage of females with CPD. Low vitamin B6 (OR 0.697; 95% CI: 0.696-0.699, p = 0.025) and vitamin D (OR 0.794; 95% CI: 0.789-0.799, p = 0.037) levels were associated with a higher rate of CPD compared to healthy controls. Our study suggests that low levels of Vitamin B6 and Vitamin D inversely correlates with the presence of CPD. These vitamin deficiencies suggest further studies on the effect of vitamin supplementation may help in patients with CPD.

Odevixibat: A Review of a Bioactive Compound for the Treatment of Pruritus Approved by the FDA

Odevixibat is synthesized through chemical modification of Benzothiazepine's structure. It is a tiny chemical that inhibits the ileal bile acid transporter and is used to treat a variety of cholestatic illnesses, including progressive familial intrahepatic cholestasis (PFIC). For cholestatic pruritus and liver disease development, bile acid transporter inhibition is a unique treatment strategy. Odevixibat reduces enteric bile acid reuptake. Oral odevixibat was also studied in children with cholestatic liver disease. Odevixibat received its first approval in the European Union (EU) in July 2021 for the treatment of PFIC in patients aged 6 months, followed by approval in the USA in August 2021 for the treatment of pruritus in PFIC patients aged 3 months. Bile acids in the distal ileum can be reabsorbed by the ileal sodium/bile acid cotransporter, a transport glycoprotein. Odevixibat is a sodium/bile acid co-transporter reversible inhibitor. An average 3 mg once-daily dose of odevixibat for a week resulted in a 56% reduction in the area under the curve of bile acid. A daily dose of 1.5 mg resulted in a 43% decrease in the area under the curve for bile acid. Odevixibat is also being evaluated in many countries for the treatment of other cholestatic illnesses, including Alagille syndrome and biliary atresia. This article reviews the updated information on odevixibat with respect to its clinical pharmacology, mechanism of action, pharmacokinetics, pharmacodynamics, metabolism, drug-drug interactions, pre-clinical studies, and clinical trials.

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.

Knowledge, Attitude and Practice for Pruritus Management in Physicians and Patients with Diabetes

Pruritus is a common dermatological condition observed in patients with diabetes, making it a dermatometabolic condition. Being multiaethiological, pruritis is caused by autoimmune, genetic, infectious and various systemic diseases. The present survey aimed to understand the knowledge, attitude and practice toward pruritus among Indian physicians and patients with diabetes presenting with pruritus. A telephonic, cross-sectional, qualitative survey was conducted among physicians and patients across five cities in India from July-August 2020. An open-ended discussion guide was used for the interview; the data were analyzed to check for common themes and trends. A majority of the consulting physicians (CPs) believed that uncontrolled diabetes is the main causal factor for pruritus in patients with diabetes and reported that currently there are no standard tests or treatment guidelines for its management. CPs emphasized proper monitoring and counseling to overcome current challenges. Patients reported a negative impact of pruritus on their daily activities and quality of life. The survey concluded that poor management of diabetes is one of the main causal factors for patients with diabetes presenting with pruritus in India. CPs emphasized controlling diabetes along with symptomatic treatment. For patients, pruritus has multifaceted effects on their health, overall well-being, and quality of life.

From chronic pruritus to neuroendocrine tumor: A case report

Chronic pruritus is a major and distressing symptom of many diseases of dermatological, neurological, psychogenic or systemic origin. This chronic itch could be a presenting sign of malignancy; therefore, paraneoplastic pruritus has also been associated with neuroendocrine tumors (NETs). This article focuses on a patient presenting with chronic pruritus for the past 12 months and who received numerous treatment schemes with very poor clinical improvement, that presented in the hospital for worsening of the chronic pruritus associated with skin rash and significant weight loss (approximately 6 kg over a 2-month period). The laboratory tests showed iron deficiency anemia, eosinophilia and negative tumor markers. In order to investigate the hypoanabolic and anemic syndromes, upper gastrointestinal endoscopy and colonoscopy, which showed no lesions or tumors, were employed. Skin biopsy was performed and antihistaminic and local steroid treatment was initiated. The patient's status worsened within a week and the patient was started on systemic steroid treatment with poor results. Computer tomography was performed to identify any tumor(s) located either in the pelvis or abdomen. A lesion was found in the terminal ileum, identified as a hypervascularized associating bulky lymphadenopathy. The patient was transferred to the surgical ward where right hemicolectomy with manual ileotransverse anastomosis L-L was performed. The histopathological result confirmed NET G2. The patient clinically improved, the skin lesions resolved and the itchiness disappeared. The general status improved significantly. NET G2 diagnosing was possible due to the atypic paraneoplastic sign: chronic pruritus. This case study highlights the association between itch and malignancy and presents an atypical way of NET presentation when all tumor markers remain negative.

Clinical and Laboratory Characteristics of Elderly Patients with Pruritus

Introduction

For elderly, pruritus is considered the most common complaint in outpatient clinic. Pruritus occurs in association with primary skin disorders and can also be caused by many diseases and drugs. The aim of the work was to study clinical and laboratory characteristics of elderly patients with pruritus in Sohag, Egypt.

Patients and Methods

A cross-sectional study was conducted on 225 patients aged ≥60 years of both sexes complaining of pruritus and 160 age- and sex-matched patient group complaining of non-pruritic dermatological diseases. CBC, ESR, renal function tests, serology for HBV and HCV and blood glucose levels were done routinely in all patients (both groups). Skin biopsy was done in some selected cases.

Results

The mean duration of pruritus was 4.23 ± 4.9 months and was generalized in 73.8% of cases with moderate severity in 35.1% with winter exacerbation in 20%. Dermatological causes of pruritus were detected in 54.2%, followed by systemic causes in 29.8%. Eczema was the most common skin cause of senile itching in 33.7%, while renal diseases were the most common systemic cause in 46.2%.

Conclusion

Senile pruritus is a common problem in elderly. Early and proper management is mandatory to improve their quality of life.

A qualitative research study on the illness perception of chronic pruritus in older Asian adults based on the Common-Sense Model of self-regulation

Background

Chronic pruritus (CP), itch lasting more than 6 weeks, is common in community‐dwelling older adults. Understanding their illness perception allows the attending physician to develop a personalised care plan to mitigate CP.

Aim

This study explores the illness perception of CP among older Asian adults in an urban community.

Design

Qualitative research was conducted, framed by the Common‐Sense Model of self‐regulation (CSM). Through in‐depth interviews (IDIs), qualitative data were gathered from Asian patients with CP, and then a thematic analysis was carried out. The emergent themes were grouped according to the five domains of CSM: ‘identity’, ‘cause’, ‘time’, ‘controllability’ and ‘consequence’.

Setting and Patients

IDIs were conducted in a Singapore public primary care clinic before the data were saturated.

Results

The CSM domains illustrate the illness perception of CP. CP was identified as a ‘problem’ rather than a disease and was often described in metaphor. Patients' perception of the cause was diverse due to the lack of provision of a clear explanation by their physicians. They opined that CP continued indefinitely. Without definite time to resolution, patients adapted their help‐ and health‐seeking behaviours to control it. The consequences included therapeutic experimentation, alternative therapy, self‐isolation, avoidance behaviours, emotional disturbance and dermatological complications.

Conclusion and Patient Contribution

Patients provided information on their perception of CP, which aligned with the CSM. A multipronged approach is needed to deliver holistic and personalised care to patients with CP, providing clarity on its natural progression, to set their expectations on its timeline, treatment effectiveness and undertake appropriate behaviour modification to adapt to its chronicity.

Riboflavin Inhibits Histamine-Dependent Itch by Modulating Transient Receptor Potential Vanilloid 1 (TRPV1)

Riboflavin, also known as vitamin B₂, isfound in foods and is used as a dietary supplement. Its deficiency (also called ariboflavinosis) results in some skin lesions and inflammations, such as stomatitis, cheilosis, oily scaly skin rashes, and itchy, watery eyes. Various therapeutic effects of riboflavin, such as anticancer, antioxidant, anti-inflammatory, and anti-nociceptive effects, are well known. Although some studies have identified the clinical effect of riboflavin on skin problems, including itch and inflammation, its underlying mechanism of action remains unknown. In this study, we investigated the molecular mechanism of the effects of riboflavin on histamine-dependent itch based on behavioral tests and electrophysiological experiments. Riboflavin significantly reduced histamine-induced scratching behaviors in mice and histamine-induced discharges in single-nerve fiber recordings, while it did not alter motor function in the rotarod test. In cultured dorsal root ganglion (DRG) neurons, riboflavin showed a dose-dependent inhibitory effect on the histamine- and capsaicin-induced inward current. Further tests wereconducted to determine whether two endogenous metabolites of riboflavin, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), have similar effects to those of riboflavin. Here, FMN, but not FAD, significantly inhibited capsaicin-induced currents and itching responses caused by histamine. In addition, in transient receptor potential vanilloid 1 (TRPV1)-transfected HEK293 cells, both riboflavin and FMN blocked capsaicin-induced currents, whereas FAD did not. These results revealed that riboflavin inhibits histamine-dependent itch by modulating TRPV1 activity. This study will be helpful in understanding how riboflavin exerts antipruritic effects and suggests that it might be a useful drug for the treatment of histamine-dependent itch.

A basophil-neuronal axis promotes itch

Itch is an evolutionarily conserved sensation that facilitates expulsion of pathogens and noxious stimuli from the skin. However, in organ failure, cancer, and chronic inflammatory disorders such as atopic dermatitis (AD), itch becomes chronic, intractable, and debilitating. In addition to chronic itch, patients often experience intense acute itch exacerbations. Recent discoveries have unearthed the neuroimmune circuitry of itch, leading to the development of anti-itch treatments. However, mechanisms underlying acute itch exacerbations remain overlooked. Herein, we identify that a large proportion of patients with AD harbor allergen-specific immunoglobulin E (IgE) and exhibit a propensity for acute itch flares. In mice, while allergen-provoked acute itch is mediated by the mast cell-histamine axis in steady state, AD-associated inflammation renders this pathway dispensable. Instead, a previously unrecognized basophil-leukotriene (LT) axis emerges as critical for acute itch flares. By probing fundamental itch mechanisms, our study highlights a basophil-neuronal circuit that may underlie a variety of neuroimmune processes.

Real-World, Non-Interventional, Observational Study of Hydroxyzine Hydrochloride in Chronic Pruritus: a Prospective, Non-Comparative Study

INTRODUCTION

Although hydroxyzine is widely used for symptom relief in pruritus, its clinical safety and efficacy data in the Indian setting are scarce. We conducted a study to assess the effectiveness and tolerability of hydroxyzine in the management of Indian patients with chronic pruritus in a real-world setting.

METHODS

This was a prospective, observational, patient-reported outcomes (PRO) study in patients with chronic pruritus due to dermatological causes treated with hydroxyzine as per the clinician's discretion for a period of up to 12 weeks. The primary outcome was improvement in quality of life from baseline, assessed using the 10-point Dermatology Quality of Life Index (DLQI) at week 12 of the study period. Secondary outcomes were improvement in the pruritus scores (5-D itch scale) at 12 weeks, improvements in the DLQI and 5-D itch scores at 2, 4 and 8 weeks and safety.

RESULTS

The study included 400 patients (179 males, 221 females) from 7 dermatology centres across India. Of the 400 patients recruited, 391 patients completed at least 2 weeks of treatment. There was significant (p < 0.0001) improvement from baseline in the DLQI scores and 5-D itch scores at 2, 4, 8 and 12 weeks; 189/391 (48.34%) patients had symptom relief leading to early termination. Overall, the treatment was well tolerated with a total of 11 mild-to-moderate adverse events reported during the study, which included dizziness, constipation, drowsiness, dry mouth and sedation. All events resolved without any intervention. There were no serious adverse events.

CONCLUSION

This real-world, observational, PRO study demonstrates that hydroxyzine significantly improves symptoms of pruritus and quality of life in patients with chronic pruritus due to dermatological causes over 12 weeks. Despite the sedating potential of the drug, hydroxyzine is well tolerated in real-world settings.

TRIAL REGISTRATION

CTRI/2017/06/008847.

FUNDING

Dr. Reddy's Laboratories.