Chronic kidney disease-associated pruritus: impact on quality of life and current management challenges

Dealing with an uncertain future: a survey study on what patients with chronic kidney disease actually want to know

Background

Prognostic uncertainty is a recurring theme among patients with chronic kidney disease (CKD). We developed a survey to explore whether CKD patients want to know more about their future, and if so, which topics they prioritize. In addition, we explored differences between several subgroups.

Methods

A survey was constructed and tested in collaboration with the Dutch Kidney Patients Association. The survey consisted of three parts: (i) demographics, (ii) considerations about the future, and (iii) prognostic information. The survey was distributed among CKD patients (all stages) through patient associations and via healthcare professionals in two Dutch hospitals. Descriptive statistics were used to summarize the results. All results were stratified by population, sex, and age.

Results

A total of 163 patients (45 CKD, 26 dialysis, and 92 kidney transplantation) participated in the survey. The mean age was 63.9 (SD 12.0) and 48.5% was male. Most patients think about their future with CKD occasionally (56.4%) or often (35.0%). Nearly half of the patients (49.7%) discuss the future with their nephrologist, some (19.6%) do not but would like to, and 20 (15.3%) prefer not to. Most patients (73.6%) want more prognostic information, regardless of it being positive or negative. Key topics to receive prognostic information about were laboratory values, symptoms, and physical well-being. Dialysis patients prioritized mental over physical well-being. CKD patients without kidney replacement therapy (KRT) indicated thinking about, and discussing their future more regularly than KRT patients.

Conclusions

Patients with CKD contemplate their future regularly and express interest in receiving prognostic information on a variety of topics. One in five patients currently do not discuss their future with CKD with their nephrologist, despite wanting to do so. These findings underline the need to tailor prognostic information provision to patients' preferences, advocating more attention to this subject both in research and clinical practice.

Efficacy and Safety of Omega-3 Fatty Acids in Ameliorating Pruritus in Adult Patients With Chronic Kidney Disease: A Meta-Analysis of Randomized Controlled Trials

Chronic kidney disease-associated pruritus (CKD-aP) represents a common distressing problem in patients with end-stage renal disease. This study aimed to assess the efficacy and safety of omega-3 supplementation in the treatment of CKD-aP. MEDLINE/PubMed, Cochrane Central Register of Controlled Trials, Web of Science, ProQuest, and Scopus databases were searched systematically for articles published from inception until May 21, 2024. Outcomes were pruritus severity at the end of the study or its change from baseline (primary) and intervention-related adverse effects (secondary). Results were pooled as standardized mean difference (SMD) and risk ratio (RR) for numeric and dichotomous outcomes, respectively, along with their 95% confidence intervals (CIs). Eight studies were included. Treatment with omega-3 fatty acids showed a significantly lower severity of CKD-aP at the end of treatment (pooled SMD (95% CI) = -1.03 (-1.85, -0.22), p = 0.024) and changed from baseline (pooled SMD (95% CI) = -0.93 (-1.57, -0.28), p = 0.014). Omega-3 supplementation reduced the risk of CKD-aP (pooled RR (95% CI) = 0.68 (0.12, 3.81), p = 0.661). Omega-3 fatty acid supplementation appears to be a promising effective and safe treatment for CKD-aP. However, the included studies had several limitations that warrant further high-quality studies to elucidate its effect and investigate the causes of non-response in patients who did not improve.

[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.

Eicosapentaenoic acid supplementation alleviates pruritus, enhances skin moisture, and mitigates depression in maintenance hemodialysis patients

Background

The objective of this study is to investigate the effects of oral supplementation with eicosapentaenoic acid (EPA) on circulating inflammatory factors, cardiometabolic parameters, skin moisturization, and the consequent symptoms of pruritus and depression in maintenance hemodialysis patients.

Materials and methods

A total of 60 maintenance hemodialysis patients with severe pruritus symptoms completed this randomized, placebo-controlled study. Subjects of treatment group (n = 30) were instructed to consume 1000 mg fish oil (>900 mg EPA) and subjects of placebo group (n = 30) were instructed to consume 1000 mg soybean oil twice daily for 3 months. 5-D pruritus scoring, the Beck Depression Inventory (BDI) scale, skin moisture, serum creatinine, inflammatory factors, and cardiometabolic parameters were examined at baseline, and at the first, second, and third month post-supplementation.

Results

A significantly decreased pruritus level was observed in the treatment group, whereas an opposite result was observed in the placebo group. Increased skin moisture levels on both the face and arms were observed in the treatment group, but not in the placebo group. Supplementation of EPA significantly decreased serum CRP and IL-6 levels. Significant decreases in total cholesterol (CHO), and triglycerides (TG) levels were observed; however, a decrease in high-density lipoprotein (HDL) level was observed in the treatment group. There was no change in plasma creatinine (CR) observed in both groups. A significantly decreased BDI score was observed, whereas the opposite result was observed in the placebo group. A correlational study showed that the severity of pruritus was significantly associated with skin moisture and serum CRP. The severity of pruritus was also positively correlated with the BDI score.

Conclusion

Supplementation of EPA may provide multiple benefits including alleviating pruritus symptoms, addressing skin dryness, and mitigating depression in maintenance hemodialysis patients.

Practical Use of Patient-Reported Outcome Measures in Chronic Kidney Disease-Associated Pruritus

Regulatory and clinical stakeholders are increasingly advocating for the use of patient-reported outcome (PRO) measures; however, the use of PROs is still not widespread. Patient reports are often the best ways to diagnose and monitor the effect of treatment on symptoms when the symptoms are subjective, as with pruritus. While many PRO tools are available to assess the severity of pruritus and its impact on quality of life (e.g., sleep), these are not used in a consistent manner and their results may not translate into clinical action. In this article, we present an introduction to PROs and their use in the assessment of chronic kidney disease-associated pruritus, as well as a practical guide to some of the PRO tools currently available, to empower all members of the nephrology patient care team to use these tools appropriately for the benefit of the patient.

Difelikefalin improves itch-related sleep disruption in patients undergoing haemodialysis

BACKGROUND

Poor sleep quality is associated with higher mortality and lower quality of life in patients with chronic kidney disease-associated pruritus (CKD-aP). Difelikefalin reduces itch in patients with CKD-aP undergoing haemodialysis (HD). This post hoc analysis of the Phase 3 difelikefalin studies (Study 3105 and the pooled dataset from KALM-1 and KALM-2) evaluated whether itch reduction in individuals with CKD-aP improved sleep quality.

METHODS

Itch intensity was assessed in patients undergoing HD who had moderate-to-severe CKD-aP treated with intravenous difelikefalin (0.5 µg/kg, three times weekly) (N = 222, Study 3105; N = 426, KALM-1 and -2) or placebo (N = 425, KALM-1 and -2) for 12 weeks, using the Worst Itch Intensity Numerical Rating Scale (WI-NRS). Sleep quality was assessed using the sleep disability question of the 5-D Itch Scale (5-D SDQ) in all studies and, in Study 3105, with the Sleep Quality Numeric Rating Scale (SQ-NRS).

RESULTS

Greater improvements in sleep quality were observed in patients with ≥3-point versus <3-point WI-NRS improvement using SQ-NRS in Study 3105 [mean (95% confidence interval) -5.2 (-5.6, -4.8) vs -1.5 (-2.0, -1.0)] and 5-D SDQ in KALM-1 and -2 [-1.8 (-2.1, -1.6) vs -0.8 (-1.1, -0.4)]. SQ-NRS and WI-NRS scores were highly correlated at both baseline and Week 12 in Study 3105 (Spearman correlation coefficient: 0.77 and 0.84, respectively). Correlations were also observed between 5-D SDQ and WI-NRS scores in Study 3105 and KALM-1 and -2.

CONCLUSIONS

In patients undergoing HD with moderate-to-severe CKD-aP, itch reduction with intravenous difelikefalin was associated with improved sleep quality. As disturbed sleep may contribute to mortality and morbidity in CKD-aP, difelikefalin may help to address a major clinical burden by improving sleep quality, secondary to itch relief.

TRIAL REGISTRATION

KALM-1 (NCT03422653), KALM-2 (NCT03636269), Study 3105 (NCT03998163).

Prurigo Nodularis: Pathogenesis and the Horizon of Potential Therapeutics

Chronic pruritus that lasts for over 6 weeks can present in various forms, like papules, nodules, and plaque types, with prurigo nodularis (PN) being the most prevalent. The pathogenesis of PN involves the dysregulation of immune cell-neural circuits and is associated with peripheral neuropathies, possibly due to chronic scratching. PN is a persistent and challenging condition, involving complex interactions among the skin, immune system, and nervous system. Lesional skin in PN exhibits the infiltration of diverse immune cells like T cells, eosinophils, macrophages, and mast cells, leading to the release of inflammatory cytokines and itch-inducing substances. Activated sensory nerve fibers aggravate pruritus by releasing neurotransmitters, perpetuating a vicious cycle of itching and scratching. Traditional treatments often fail, but recent advancements in understanding the inflammatory and itch transmission mechanisms of PN have paved the way for innovative therapeutic approaches, which are explored in this review.

The relationship between fatigue, pruritus, and thirst distress with quality of life among patients receiving hemodialysis: a mediator model to test concept of treatment adherence

Hemodialysis is a conservative treatment for end-stage renal disease. It has various complications which negatively affect quality of life (QOL). This study aimed to examine the relationship between fatigue, pruritus, and thirst distress (TD) with QOL of patients receiving hemodialysis, while also considering the mediating role of treatment adherence (TA). This cross-sectional study was carried out in 2023 on 411 patients receiving hemodialysis. Participants were consecutively recruited from several dialysis centers in Iran. Data were collected using a demographic information form, the Fatigue Assessment Scale, the Thirst Distress Scale, the Pruritus Severity Scale, the 12-Item Short Form Health Survey, and the modified version of the Greek Simplified Medication Adherence Questionnaire for Hemodialysis Patients. Covariance-based structural equation modeling was used for data analysis. The structural model and hypothesis testing results showed that all hypotheses were supported in this study. QOL had a significant inverse association with fatigue, pruritus, and TD and a significant positive association with TA. TA partially mediated the association of QOL with fatigue, pruritus, and TD, denoting that it helped counteract the negative association of these complications on QOL. This model explained 68.5% of the total variance of QOL. Fatigue, pruritus, and TD have a negative association with QOL among patients receiving hemodialysis, while TA reduces these negative associations. Therefore, TA is greatly important to manage the associations of these complications and improve patient outcomes. Healthcare providers need to assign high priority to TA improvement among these patients to reduce their fatigue, pruritus, and TD and improve their QOL. Further studies are necessary to determine the most effective strategies for improving TA and reducing the burden of complications in this patient population.

Pathways for Diagnosing and Treating CKD-Associated Pruritus: A Narrative Review

Purpose of Review

Chronic kidney disease (CKD)-associated pruritus is a common, persistent, and distressing itch experienced by patients across the CKD spectrum. Although the disorder is associated with adverse outcomes and poor health-related quality of life, it remains underdiagnosed and undertreated. The purpose of this narrative review is to offer health care providers guidance on how to effectively identify, assess, and treat patients with CKD-associated pruritus, with the goal of reducing symptom burden and improving patient-important outcomes, such as quality of life (QoL).

Sources of Information

A panel of nephrologists and researchers from across Canada and the United States was assembled to develop this narrative review based on the best available data, current treatment guidelines, and their clinical experiences.

Methods

A panel of nephrologists who actively care for patients with pruritus receiving dialysis from across Canada was assembled. Two researchers from the United States were also included based on their expertise in the diagnosis and management of CKD-associated pruritus. Throughout Spring 2023, the panel met to discuss key topics in the identification, assessment, and management of CKD-associated pruritus. Panel members subsequently developed summaries of the pertinent information based on the best available data, current treatment guidelines, and added information on their own clinical experiences. In all cases, approval of the article was sought and achieved through discussion.

Key Findings

This narrative review provides pragmatic guidance addressing: (1) methods for screening CKD-associated pruritus, (2) assessing severity, (3) management of CKD-associated pruritus, and (4) suggested areas for future research. The panel developed a 3-pillar framework for proactive assessment and severity scoring in CKD-aP: systematic screening for CKD-associated pruritus (pillar 1), assessment of pruritus intensity (pillar 2), and understanding the impact of CKD-associated pruritus on the patient's QoL (pillar 3). Management of CKD-associated pruritus can include ensuring optimization of dialysis adequacy, achieving mineral metabolism targets (ie, calcium, phosphate, and parathyroid hormone). However, treatment of CKD-associated pruritus usually requires additional interventions. Patients, regardless of CKD-associated pruritus severity, should be counseled on adequate skin hydration and other non-pharmacological strategies to reduce pruritus. Antihistamines should be avoided in favor of evidence-based treatments, such as difelikefalin and gabapentin.

Limitations

A formal systematic review (SR) of the literature was not undertaken, although published SRs were reviewed. The possibility for bias based on the experts' own clinical experiences may have occurred. Key takeaways are based on the current available evidence, of which head-to-head clinical trials are lacking.

Funding

This work was funded by an arm's length grant from Otsuka Canada Pharmaceutical Inc. (the importer and distributer of difelikefalin in Canada). LiV Medical Education Agency Inc. provided logistical and editorial support.

Impact of Difelikefalin on the Health-Related Quality of Life of Haemodialysis Patients with Moderate-To-Severe Chronic Kidney Disease-Associated Pruritus: A Single-Arm Intervention Trial

OBJECTIVE

Chronic kidney disease-associated pruritus (CKD-aP) can have a substantial negative impact on health-related quality of life (HRQoL), including an increased risk of depression, anxiety and sleep disturbance. This trial aimed to assess the impact of intravenous difelikefalin on HRQoL in haemodialysis patients with moderate-to-severe CKD-aP.

METHODS

Post hoc analysis of an open-label, multicentre, single-arm intervention trial assessed pruritus severity and HRQoL at baseline and at 12 weeks of difelikefalin treatment using Worst Itching Intensity Numerical Rating Scale (WI-NRS), Sleep Quality Numeric Rating Scale (SQ-NRS), 5-D itch scale, Skindex-10 scale, EQ-5D-5L with Pruritus Bolt-On (EQ-PSO).

RESULTS

A total of 222 patients received ≥ 1 dose of difelikefalin, and 197 patients completed 12 weeks of difelikefalin treatment. Clinically meaningful changes from baseline to 12 weeks were observed in all disease-specific measures: 73.7% of patients achieved a ≥ 3-point reduction in the weekly mean of 24 h WI-NRS scores and 66% of patients experienced ≥ 3-point improvements in SQ-NRS scores. Improvements were also observed in all Skindex-10 scale and 5-D itch scale domain scores. The percentage of patients reporting no problems in all EQ-PSO domains increased from 1.4 to 24.7% (p < 0.001), respectively. Patients' generic HRQoL EQ-5D-5L mean utility and EQ-5D visual analogue scale scores increased from baseline to 12 weeks: mean changes 0.04 (p = 0.001) and 2.8 (p = 0.046), respectively.

CONCLUSIONS

Patients undergoing haemodialysis with moderate-to-severe CKD-aP receiving difelikefalin reported experiencing clinically meaningful improvements in both their pruritus symptoms and itch-related QoL.

CLINICALTRIALS

gov registration number, NCT03998163; first submitted, 7 May 2019.

Symptom perception and self-care practice for uraemic pruritus in patients receiving haemodialysis

BACKGROUND

Due to the recurrent nature of uraemic pruritus among patients receiving haemodialysis, self-care can offer patients a means to ameliorate this symptom. Qualitative data on self-care of uraemic pruritus are limited.

OBJECTIVE

To explore how patients on haemodialysis perceive uraemic pruritus, implement self-care practice, and appraise the outcome of self-caring uraemic pruritus.

DESIGN

The Common Sense Model of Self-Regulation guided the study design.

PARTICIPANTS AND APPROACHES

Data were collected through face-to-face interviews with 30 patients receiving haemodialysis who were aged from 50 to 89 years and had had uraemic pruritus for more than 6 weeks. Interviews were audio recorded, and verbatim transcriptions of interviews were analysed.

FINDINGS

Our participants generally used life-related analogies to describe uraemic pruritus, which they reviewed as a momentarily controllable symptom with an endless timeline. Most participants reported limited knowledge of the aetiology and multifaceted impacts of uraemic pruritus on their daily life and emotional status. The impacts on daily life included decreased zest for activities and sleep disturbances. Physical management of uraemic pruritus involved daily substance use and interventions employed during pruritic episodes. Psychological managements involved preferences for indoor activities and a fatalistic outlook. Unsatisfactory outcomes and psychological burdens from self-care practice were reported.

CONCLUSIONS

Life experiences shape symptom presentation and self-care practice in patients on haemodialysis. The modalities for self-caring for uraemic pruritus are diverse but not remarkably effective. Performing self-care tasks places a substantial burden on patients. Individualised educational programs should be developed to improve the outcome of self-care practice.

Effectiveness of omega-3 fatty acid supplementation for pruritus in patients undergoing hemodialysis

Background

Patients undergoing hemodialysis (HD) frequently experience the chronic kidney disease-associated pruritus (CKD-aP).

Objective

The aim of this study was to investigate the effectiveness of omega-3 supplementation in the management of CKD-aP in patients undergoing hemodialysis.

Methods

In this triple blind, randomized clinical trial, the effect of the omega-3 supplement on uremic CKD-aP was assessed in 112 chronic hemodialysis patients at Caspian Hemodialysis Center in Rasht, Iran. Patients were randomly divided into the intervention group receiving omega-3 supplements (3 g/day) and the control group receiving placebo containing MCT oil for 2 months.

Results

Omega-3 supplementation had no effect on CKD-aP. The results did not change after adjusting for age and sex, additional adjustments for weight, height, physical activity, smoking, and alcohol use, additional adjustments for underlying diseases and weight, height, physical activity, smoking, and drinking alcohol, and further adjustments for underlying diseases and biochemical indices.

Discussion

Omega-3 supplementation for 2 months had no effect on CKD-aP in patients with CKD. Further studies with longer duration are warranted.

Clinical Trial Registration

https://www.irct.ir/trial/66638, IRCT20151226025699N6.

Chronic kidney disease-associated pruritus: what is known and its application in children

Chronic kidney disease-associated pruritus (CKD-aP) or uremic pruritus (UP) is a frequent symptom in patients with kidney failure receiving kidney replacement therapy. Severe chronic kidney disease-associated pruritus correlates with poor outcome in patients on dialysis. It is multifactorial in etiology and has a significant impact on quality of life. There is, however, limited data for children. This review summarizes current epidemiology, clinical characteristics, pruritus scoring systems, and available therapeutic options for pruritus in patients with chronic kidney disease and those receiving dialysis. Optimal care requires proper awareness of the severity of symptoms, the impact on quality of life, and the possible long-term outcomes. Optimizing dialysis prescription and correcting electrolyte abnormalities are important treatment targets. A wide range of therapeutic options is also available although none are well-studied in children. An earlier recognition of this debilitating symptom in children and treatment is imperative. A higher resolution version of the Graphical abstract is available as Supplementary information.

Uremic pruritus: prevalence, determinants, and its impact on health-related quality of life and sleep in Indian patients undergoing hemodialysis

BACKGROUND

Uremic pruritus has an impact on the quality of life and sleep of hemodialysis patients, but the majority of cases go unreported and untreated unless severe, due to a lack of awareness. The purpose of this study is to determine the prevalence, associated factors, and impact on health-related quality of life (HR-QOL) and sleep in hemodialysis patients.

METHODOLOGY

A single-center observational study of 3 months wherein 120 adults on maintenance hemodialysis were included. Baseline characteristics, dialysis-related factors, and lab parameters influencing uremic pruritus were recorded. Those with uremic pruritus completed "12-item pruritus severity scale (12-PSS)", "SKINDEX10", and "Itch-MOS" questionnaires to evaluate severity, impact on HR-QOL, and sleep respectively.

RESULTS

Sixty seven over one hundred twenty (55.83%) patients had pruritus and majority were mild (40.83%) as per 12-PSS. Those with pruritus (n=67) had a mean age of 56.5±11.3 years, most were males (82%), chronic glomerulonephritis (29.1%) was the commonest cause of end-stage kidney disease, 3 active smokers, and 4 seropositive. 65(97%) patients were on twice-weekly dialysis, 36/67 had <5 years' dialysis vintage and acceptable adequacy. There was no significant association between uremic pruritus and dialysis-related/laboratory parameters. Patients with uremic pruritus demonstrated significantly worse "HR-QOL" (p<0.001) on the "SKINDEX-10", and patients' "Itch-MOS" scores demonstrated a significant decline in sleep quality with increasing pruritus severity (p<0.001).

CONCLUSION

The majority of patients on maintenance hemodialysis experience uremic pruritus. None of the clinical characteristics, dialysis-related factors, and laboratory parameters affected uremic pruritus. Uremic pruritus patients had the worst HR-QOL & their sleep quality significantly declined as pruritus severity escalated.

TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION

Study approval was obtained from Institutional Research Committee and Institutional Ethical Committee (IEC 642/2021). Clinical Trial Registry of India (CTRI) registration (CTRI/2022/01/039143) was also obtained.

Chronic Kidney Disease-Associated Pruritus, Still a Vexing Problem

Chronic kidney disease-associated pruritus (CKD-aP), formerly termed uremic pruritus, is a severely distressing condition that is common (60% of patients on dialysis) and frequently underdiagnosed and untreated.1,2 The pruritus can be severe enough to diminish sleep and is associated with worse mortality rates, as demonstrated in several large studies.1,2 It can also occur in nondialysis patients with stage 3 to 5 CKD, with an increasing prevalence in patients with worsening kidney function, age, and medical comorbidities. The pathophysiology likely involves many factors and molecules.3.

Chronic kidney disease-associated pruritus (CKD-aP) is associated with worse quality of life and increased healthcare utilization among dialysis patients

PURPOSE

Chronic pruritus significantly impairs hemodialysis patients' health status and quality of life (QOL) and it is associated with higher mortality rate, more frequent hospitalizations, poorer dialysis and medication adherence, and deteriorated mental status. However, pruritus is still underestimated, underdiagnosed, and undertreated in the real-life clinical scenario. We investigated prevalence, clinical characteristics, clinical correlates, severity as well as physical and psychological burden of chronic pruritus among adult hemodialysis patients in a large international real-world cohort.

METHODS

We conducted a retrospective cross-sectional study of patients registered in 152 Fresenius Medical Care (FMC) NephroCare clinics located in Italy, France, Ireland, United Kingdom, and Spain. Demographic and medical data were retrieved from the EuCliD® (European Clinical) database, while information on pruritus and QoL were abstracted from KDQOL™-36 and 5-D Itch questionnaire scores.

RESULTS

A total of 6221 patients were included, of which 1238 were from France, 163 Ireland, 1469 Italy, 2633 Spain, and 718 UK. The prevalence of mild-to-severe pruritus was 47.9% (n = 2977 patients). Increased pruritus severity was associated with increased use of antidepressants, antihistamines, and gabapentin. Patients with severe pruritus more likely suffered from diabetes, more frequently missed dialysis sessions, and underwent more hospitalizations due to infections. Both mental and physical QOL scores were progressively lower as the severity of pruritus increased; this association was robust to adjustment for potential confounders.

CONCLUSION

This international real-world analysis confirms that chronic pruritus is a highly prevalent condition among dialysis patients and highlights its considerable burden on several dimensions of patients' life.

The Burden of Pruritus Associated With CKD: A Mixed Methods Analysis Among Patients Undergoing Dialysis

Rationale & Objective

Despite its prevalence and distress to patients, chronic kidney disease-associated pruritus (CKD-aP) is poorly characterized, which may contribute to the condition's underdiagnosis and inadequate management. This study aimed to understand the symptom experience of patients with CKD-aP and the extent to which pruritus impacts their lives.

Study Design

Mixed methods study including one-on-one qualitative interviews and completion of the Skindex-10 Questionnaire (measuring itch-related quality of life).

Setting & Participants

A total of 23 patients undergoing hemodialysis and reporting pruritus at 4 dialysis centers in the United States.

Analytical Approach

Interviews followed a semistructured guide that included targeted and follow-up questions to elicit discussion of patients' symptoms of pruritus, including frequency and variability, impact on activities of daily living, and emotional and social functioning. Interviews were digitally audio-recorded. A coding dictionary was developed from transcripts to analyze themes and concepts.

Results

Participants described their itch with various terms, including "numbness," "pain," and "tingling" on their skin. Itch affected multiple areas but especially the back, usually occurred daily, and was often worse at night. For some, itching was a constant experience. Patients relieved their itch through scratching and various off-label treatments; some reported skin damage from excessive scratching and most indicated treatments provided limited relief. Pruritus considerably disrupted physical function, including sleep, daily activities, social functioning and relationships, and emotional and psychological wellbeing. All participants reported being bothered by their itching during the past week on the Skindex-10 Questionnaire.

Limitations

All participants were from the United States, so the findings may not be generalizable to other countries.

Conclusions

Although symptom experience varies considerably, CKD-aP causes severe distress for many patients undergoing hemodialysis and can profoundly impair their quality of life. The results of this study show the impact of itch from patients' perspectives and highlight the need for greater awareness and better management of this condition.

Plain-Language Summary

Patients with chronic kidney disease often experience itching, or pruritus, but its importance to patients is regularly overlooked. This study used one-on-one interviews to investigate patients' experiences of chronic kidney disease-associated pruritus and how it impacts their lives. We found that participants experienced itch on various body areas and used different words to describe their itch (eg, "numbness" and "pain"). Some reported skin damage from excessive scratching, and many used off-label treatments and other interventions (eg, rubbing alcohol and multiple showers daily), which provided limited relief. For many, itching was experienced daily and severely disrupted sleep, daily activities, interactions with others, and mental wellbeing. These findings reveal chronic kidney disease-associated pruritus severely impacts patients and highlights the need for improved management of this condition.

Chronic Kidney Disease-Associated Pruritus and Quality of Life: Learning from Our Patients

Chronic kidney disease-associated pruritus is itching directly related to kidney disease that cannot be explained by any other condition. Despite technological advances in the different aspects of dialysis sessions and the best treatment for chronic kidney disease patients, it is still a common problem in our patients. The many complex physiological mechanisms involved, the different hypotheses made over the years on the aetiology of the condition, and the great clinical variability may partially explain the limited knowledge about this problem and the difficulties in treating it. The presence of all these factors leads to the persistence of unpleasant symptoms, which must affect the disease burden and quality of life of kidney patients. Through the presentation of an illustrative clinical case, the aim of this review article is to highlight the need for adequate diagnosis and an improved approach to all aspects of chronic kidney disease-associated pruritus, in view of the heavy burden of the disease and the huge impact on the patient's quality of life.

Management of Uremic Xerosis and Chronic Kidney Disease (CKD)-Associated Pruritus (CKD-ap) With Topical Preparations: A Systematic Review and Implications in the Indian Context

Uremic xerosis and chronic kidney disease (CKD)-associated pruritus (CKD-ap) are the most commonly occurring dermatological problems faced by most of the CKD patients on hemodialysis which are not only annoying and draining to the patients but also have an intense effect on patients' quality of life. The PubMed, Scopus, Google Scholar, and Web of Science databases were searched for the literature with the following search terms: uremic xerosis OR CKD-ap OR uremic pruritus AND topical therapy OR topical ointment OR natural oil from the year 2002 -2022, and finally, 22 articles were chosen to write this review. Out of 22 studies, six used pharmacological preparations and remaining 16 studies used natural oils and components. All the articles were experimental studies (Pre/Quazi/RCT/True experimental) focusing on managing itch and xerosis associated with CKD and hemodialysis by topical application. The topical agents tried in various research studies are effective in managing itch and xerosis associated with CKD. They are safe, easy to use, and without allergic reactions. Natural oils like almond, chia seed, clove, glycerin, paraffin, and virgin coconut oil are readily available in home-care settings and can be used as a nurse-led intervention. Topical preparations for uremic xerosis and pruritus are effective, safe, and easy to apply on large body surface areas without systematic side effects. Natural oil-based topical preparations are cost-effective, safe, and easy to use.

The effectiveness of sertraline in alleviating uremic pruritus in hemodialysis patients: a randomized clinical trial

INTRODUCTION

Uremic pruritus (UP) is a common and distressing symptom in end stage renal disease (ESRD) patients. Many approaches have been tested to improve UP without a clear success. We aimed to assess the effect of sertraline on UP in hemodialysis (HD) patients.

METHODS

This research is a double-blinded, placebo-controlled, multicentric randomized clinical trial which included sixty patients maintained on regular HD. Patients were allocated to receive sertraline 50 mg twice daily or placebo for 8 weeks. The Visual analogue scale (VAS) and the 5-D itch scale were used to assess pruritus before and after the course of treatment.

RESULTS

At study end in sertraline group, there was a significant decrease from baseline findings in the VAS score (p < 0.001), and the 5-D itch scale (p < 0.001). On the other hand, in placebo group the VAS score showed a slight non-significant decrease (p = 0.469), and the 5-D scale (p = 0.584) increased from baseline measurements. The percentage of patients with severe and very severe pruritus decreased significantly in the sertraline group in both scores [(VAS score: p = 0.004), (5-D itch score: p = 0.002)] with no significant change in the placebo group [(VAS score: p = 0.739), (5-D itch scale: p = 0.763)]. There was a significant positive relation between the VAS and 5-D itch scores and serum urea with p value of 0.002 and 0.001 respectively, and serum ferritin with p value of < 0.001 with both.

CONCLUSIONS

Patients treated with sertraline had a significant improvement in pruritus as compared with those who received placebo suggesting a potential role for sertraline to treat uremic pruritus in HD patients. Larger randomized clinical trials are needed to confirm these findings.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05341843. First registration date: 22/04/2022.

Perception of Spanish nephrologists on an old unsolved problem: Pruritus associated with chronic kidney disease (CKD-aP)

INTRODUCTION

Pruritus associated with chronic kidney disease is defined as the sensation of itching, in people with chronic kidney disease, in a one area or all over the body that causes the need to scratch, after having ruled out other dermatological or systemic causes. It is an old and known problem whose prevalence has been able to decrease with the improvement of dialytic techniques but which still persists and is underdiagnosed.

OBJECTIVES

The objective of this study was to analyse the current perception of nephrologists about this problem that influences the quality of life of people with chronic kidney disease through a survey.

RESULTS

135 nephrologists, most of them engaged in haemodialysis, participated. 86% considered that pruritus associated with chronic kidney disease is still a problem today that affects the quality of life. Most nephrologists believe that the main pathophysiological cause is uremic toxins (60%) and only 16% believe that it is due to the dysregulation of the opioid system/endorphins-dynorphins. Only 16% comment that the prevalence of pruritus in their centre is greater than 20%. 40% believe that the diagnosis is made because it is manifested by the patient and only 27% because it is asked by the doctor. Moreover, it is not usual to use scales to measure it or the codification in the medical records. The main treatment used is antihistamines (96%), followed by moisturizers/anaesthetics (93%) and modification of the dialysis regimen (70%).

CONCLUSIONS

Pruritus associated with chronic kidney disease is still a current problem, it is underdiagnosed, not codified and with a lack of indicated, effective and safe treatments. Nephrologists do not know its real prevalence and the different pathophysiological mechanisms involved in its development. Many therapeutic options are used with very variable results, ignoring their efficacy and applicability at the present time. The new emerging kappa-opioid-receptor agonist agents offer us an opportunity to reevaluate this age-old problem and improve the quality of life for our patients with chronic kidney disease.

Prevalence and determinants of severity of uremic pruritus in hemodialysis patients: a multicentric study

Uremic pruritus (UP) is a common and distressing symptom in patients with advanced or end-stage renal disease under hemodialysis (HD). The present multicentric study aimed to identify prevalence and determinants of severity of UP among Egyptian patients. Performed investigations included serum urea, creatinine, calcium, phosphorus, parathormone, ferritin and liver enzymes. Pruritus was evaluated using the visual analog scale. The study included 295 patients on maintenance HD. They comprised 151 patients (51.2%) with UP. Independent predictors of UP included associated hypertension (OR: 0.48, 95% CI 0.28 to 0.83, p=0.008), higher calcium levels (OR: 1.29, 95% CI 1.02 to 1.62, p=0.032), higher phosphorus levels (OR: 1.18, 95% CI 1.02 to 1.37, p=0.03) and higher high-sensitivity C-reactive protein (hsCRP) levels (OR: 1.0, 95% CI 1.0 to 1.01, p=0.049). Independent predictors of significant UP included longer HD duration (OR: 1.23, 95% CI 1.1 to 1.38, p<0.001), lack of vitamin D supplementation (OR: 3.71, 95% CI 1.03 to 13.4, p=0.045), lower albumin levels (OR: 0.32, 95% CI 0.14 to 0.74, p=0.008) and higher hsCRP levels (OR (CRP): 1.02 (1.0-1.03), p=0.011). In conclusion, UP is fairly common among Egyptian HD patients. Independent predictors of UP severity include longer HD duration, lack of vitamin D supplementation, lower albumin levels and higher hsCRP levels.

Alleviating symptoms in patients undergoing long-term hemodialysis: a focus on chronic kidney disease-associated pruritus

Since the breakthrough of kidney replacement therapy, increases in life expectancy for patients with end-stage kidney disease have been limited. However, patients have become increasingly vocal that, although mortality and life expectancy matter to them, the quality of their life, and particularly the relief of symptoms associated with their treatment, are in many cases more important. The majority of dialysis-associated symptoms and adverse effects do not currently have any approved treatments in this patient population, with the few treatments that are available used off-label, frequently without proven efficacy, yet still potentially adding further adverse effects to patients' current symptom burden. This article will illustrate how understanding the pathophysiology of a single, particularly burdensome symptom of dialysis (chronic kidney disease-associated pruritus) resulted in the design, development and regulatory approval of a treatment for that symptom. The pathway described here can be applied to other symptoms associated with dialysis, meaning that if we cannot add years to patients' lives, we can at least add life to their remaining years.

Pruritus in Chronic Kidney Disease: An Update

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

Safety and Tolerability of Difelikefalin for the Treatment of Moderate to Severe Pruritus in Hemodialysis Patients: Pooled Analysis From the Phase 3 Clinical Trial Program

Rationale & Objective

We report a pooled safety analysis of intravenous difelikefalin in participants with moderate to severe chronic kidney disease–associated pruritus (CKD-aP) treated by hemodialysis in 4 phase 3 clinical studies.

Study Design

KALM-1 and KALM-2 were randomized, double-blind, placebo-controlled, pivotal phase 3 studies; CLIN3101 (52 weeks) and CLIN3105 (12 weeks) were open-label studies.

Setting & Participants

Adults with moderate to severe CKD-aP treated by hemodialysis in North America, Europe, and the Asia-Pacific region.

Intervention

At least 1 intravenous placebo or difelikefalin dose of 0.5 mcg/kg for up to 64 weeks.

Outcomes

Safety.

Results

Safety analyses were conducted with 848 participants in the placebo-controlled cohort (424 participants each in the difelikefalin and placebo groups) and in 1,306 participants in the all-difelikefalin-exposure cohort. In the placebo-controlled cohort, the most commonly reported treatment-emergent adverse events (TEAEs), occurring in ≥2% of participants receiving difelikefalin and with a ≥1% higher incidence than placebo, were diarrhea (9.0% and 5.7%, respectively); dizziness (6.8% and 3.8%, respectively); nausea (6.6% and 4.5%, respectively); gait disturbances, including falls (6.6% and 5.4%, respectively), hyperkalemia (4.7% and 3.5%, respectively); headache (4.5% and 2.6%, respectively); somnolence (4.2% and 2.4%, respectively); and mental status changes (3.3% and 1.4%, respectively). These were mostly mild or moderate, with few leading to discontinuation. Incidence rates of TEAEs, serious TEAEs, and discontinuations because of TEAEs did not increase with long-term exposure. Three participants (0.7%) in the difelikefalin group and 5 participants (1.2%) in the placebo group died during the study.

Limitations

Pooled data from studies with different designs.

Conclusions

Intravenous difelikefalin demonstrated an acceptable safety profile, was generally well tolerated with long-term use, and may address the unmet treatment need for patients with CKD-aP treated by hemodialysis.

Funding

Cara Therapeutics, Inc.

Trial Registration

KALM-1 is registered as NCT03422653, KALM-2 as NCT03636269, CLIN3101 as NCT03281538, and CLIN3105 as NCT03998163.

Omega-3 Fatty Acids Improve Chronic Kidney Disease-Associated Pruritus and Inflammation

Background and Objectives: Chronic kidney disease-associated pruritus (CKD-aP) is a common symptom in hemodialysis patients. A frequent and intense itching sensation largely torments patients, impacts quality of life outcomes, and it has an independent association with mortality. The objective of this study is to investigate the effects of oral supplementation with omega-3 polyunsaturated fatty acid (omega-3 PUFA) on circulating interleukin-6 (IL-6), cardiometabolic parameters, skin moisturization, and the consequent symptoms of pruritus in hemodialysis patients. Materials and Methods: Volunteers on maintenance hemodialysis with very severe pruritus symptoms were enrolled in this prospective cohort study. Subjects were instructed to consume 1000 mg fish oil once daily for 3 months. Pruritus scoring, skin moisture, plasma IL-6, and cardiometabolic parameters were measured at baseline, and at the first, second, and third month post-supplementation with fish oil for assessment of the clinical significance. Results: A total of 27 patients who had a mean age of 67.33 ± 11.06 years and 3.98 ± 3.23 years on hemodialysis completed the study. Supplementation with omega-3 PUFA significantly decreased IL-6 levels (p < 0.001), but increased the levels of c-reactive protein (CRP) (p < 0.05). Evaluation of the cardiovascular risk showed significant (all p < 0.001) decreases in the total cholesterol (CHO), low-density lipoprotein (LDL), and triglycerides (TG) levels, and an increase in the high-density lipoprotein (HDL) level. A significant decrease in plasma creatinine (CR) was observed (p < 0.001), but the decrease was limited. Supplementation with omega-3 PUFA significantly improved (all p < 0.001) skin hydration on both the face and arms, as well as disease-related symptoms of pruritus. Conclusion: Omega-3 PUFA supplementation improved inflammation, renal function, cardiovascular parameters, dry skin conditions, and the consequent symptoms of pruritus in hemodialysis patients.

Comparison of Pregabalin and Ketotifen in Treatment of Uremic Pruritus in Hemodialysis Patients

This study aims to compare the efficiency of Pregabalin and Ketotifen in treatment of uremic pruritus in hemodialysis (HD) patients. Thirty HD patients were randomly divided into two groups: A (Pregabalin 50 mg 3 times a day) and B (Ketotifen 1mg twice a day). Efficacy of treatment and quality of life were weekly evaluated by visual analogue scale (VAS) and Itchy Quality of life, respectively. There was no significant difference between the two groups regarding demographic features, laboratory data, quality of life, and VAS before treatment. In the second week of treatment, the pruritus intensity was significantly lower in the Pregabalin group than the Ketotifen group (p=0.026). The mean of life quality was significantly lower in Ketotifen than Pregabalin group in weeks 1, 2, and 4 (P=0.001, P=0.001, and P=0.036, respectively). There was no significant difference between the two groups regarding the side effects of drugs. This study showed that a higher dose of Pregabalin could be a more effective treatment than Ketotifen without additive side effects in improving the quality of life in dialysis patients. This article is protected by copyright. All rights reserved.

Itching in dialysis patients: impact on health-related quality of life and interactions with sleep problems and psychological symptoms – results from the RENINE/PROMs registry

Background

Itching (pruritus) is common in dialysis patients, but little is known about its impact on health-related quality of life (HRQOL), sleep problems and psychological symptoms. This study investigates the impact of itching in dialysis patients by looking into the persistence of itching, the effect of itching on the course of HRQOL and the combined effect of itching with sleep problems and with psychological symptoms on HRQOL.

Methods

Data were obtained from the RENINE/PROMs registry and included 2978 dialysis patients who completed patient-reported outcome measures between 2018 and 2020. Itching, sleep problems and psychological symptoms were assessed with the Dialysis Symptom Index (DSI) and HRQOL with the 12-item Short Form Health Survey. Effects of itching on HRQOL and interactions with sleep problems and psychological symptoms were investigated cross-sectionally and longitudinally using linear regression and linear mixed models.

Results

Half of the patients experienced itching and in 70% of them, itching was persistent. Itching was associated with a lower physical and mental HRQOL {−3.35 [95% confidence interval (CI) −4.12 to −2.59) and −3.79 [95% CI −4.56 to −3.03]}. HRQOL remained stable during 2 years and trajectories did not differ between patients with or without itching. Sleep problems (70% versus 52%) and psychological symptoms (36% versus 19%) were more common in patients with itching. These symptoms had an additional negative effect on HRQOL but did not interact with itching.

Conclusions

The persistence of itching, its impact on HRQOL over time and the additional effect on HRQOL of sleep problems and psychological symptoms emphasize the need for recognition and effective treatment of itching to reduce symptom burden and improve HRQOL.

Psychometric validation and meaningful change thresholds of the Worst Itching Intensity Numerical Rating Scale for assessing itch in patients with chronic kidney disease-associated pruritus

Background

Chronic kidney disease-associated pruritus (CKD-aP) is characterized by persistent itch that often leads to substantially impaired quality of life. The Worst Itching Intensity Numerical Rating Scale (WI-NRS) is a single-item patient-reported outcome measure in which patients indicate the intensity of the worst itching they experienced over the past 24 h. Here, we evaluated the content validity and psychometric properties of the WI-NRS and confirmed the threshold of meaningful change in hemodialysis patients with moderate-to-severe CKD-aP.

Methods

Content validity interviews were conducted in 23 patients. Psychometric properties of the WI-NRS were assessed using data from one phase 2 (N = 174) and two phase 3 (N = 848) clinical trials investigating an anti-pruritic treatment. Anchor-based methods were used to confirm meaningful within-patient change score thresholds in the phase 3 trial patients and mixed-method exit interviews (N = 70) contributed further insight.

Results

Content validity interviews indicated patients considered the WI-NRS to be straightforward, comprehensive, and relevant. Test–retest reliability was strong in both trial cohorts (intraclass correlation coefficients > 0.75). Construct validity analyses indicated high correlation between the WI-NRS and other measures of itch. Anchor-based analyses showed a reduction of ≥ 3 points from baseline score represented an appropriate clinically meaningful within-patient change on the WI-NRS. In the exit interviews, all patients with a reduction ≥ 3 points considered the change meaningful.

Conclusions

The WI-NRS is a reliable, valid, and responsive measure of itch intensity for patients with moderate-to-severe CKD-aP. These results support its use to assess treatment efficacy and in clinical evaluation and management of pruritus in hemodialysis patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41687-021-00404-z.

Itching is a distressing medical condition common in patients with chronic kidney disease, especially those undergoing hemodialysis. The itch often leads to skin damage due to a continuous and uncontrollable urge to scratch. It affects about 60% of hemodialysis patients and can be severe enough to seriously affect quality of life. At present, there are no approved therapies. To evaluate whether new treatments for itch are effective, clinicians need to assess if the intensity of itch decreases over time. However, because itch intensity can only be measured accurately by the person experiencing it, a measure is required that can be easily understood and used by patients. This study evaluated a scale in which patients mark a number between ‘0’ (corresponding to no itch) and ‘10’ (the worst itching imaginable), to describe the worst itch intensity they experienced over the last 24 hours. Using data from three clinical trials of a novel treatment for itch in patients undergoing hemodialysis with moderate-to-severe pruritus, we found that the scale was reliable in repeat-testing experiments, and mirrored other methods of measuring changes in itch. In interviews, patients said they found the scale straightforward and easy to complete. Our analysis and patients’ opinions showed a 3-point reduction in itch intensity on the scale represented a meaningful improvement. These findings support the use of this scale to assess the efficacy of new treatments and in clinical evaluation and management of pruritus in patients with chronic kidney disease.

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

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

Epidemiology and burden of chronic kidney disease-associated pruritus

Chronic kidney disease–associated pruritus (CKD-aP) is a common, yet underrecognized condition in patients with CKD and end-stage kidney disease (ESKD). Real-world observational studies indicate that CKD-aP affects up to 80% of ESKD patients undergoing haemodialysis (HD), with ∼40% experiencing moderate to severe itch. CKD-aP can negatively impact patients’ mental and physical health-related quality of life (HRQoL) and is also associated with sleep disturbance and depression. Several studies have found that CKD-aP is a predictor of adverse medical outcomes, including an increased risk of hospitalizations and mortality. In this article we review the literature relating to the epidemiology of CKD-aP to describe its prevalence across the treatment spectrum of CKD (non-dialysis, HD, peritoneal dialysis and transplant recipients) and to summarize potential risk factors associated with its development. We also review key data from studies that have evaluated the impact of CKD-aP on HRQoL and medical outcomes.

Chronic Intractable Pruritus in Chronic Kidney Disease Patients: Prevalence, Impact, and Management Challenges - A Narrative Review

Chronic kidney disease (CKD) is recognized as a leading public health problem and causes numerous health complications. One of the most common and burdensome dermatological symptoms affecting patients undergoing dialysis is CKD-associated pruritus (CKD-aP). This condition not only has a negative impact on sleep, mood, daily activities, and quality of life but also increases the mortality risk of hemodialyzed patients. Despite that, this condition is greatly underestimated in clinical practice. Due to the complex and still not fully understood etiopathogenesis of CKD-aP, the choice of an effective therapy remains a challenge for clinicians. Most common therapeutic algorithms use topical treatment, phototherapy, and various systemic approaches. This review aimed to summarize most recent theories about the pathogenesis, clinical features, and treatment of CKD-aP.

Systemic causes of non-dermatologic chronic pruritus in the pediatric population and their management: An unexplored area

Chronic pruritus associated with systemic diseases in the pediatric population has been infrequently addressed in the literature. This review focuses on chronic pruritus presenting without cutaneous manifestations. Common systemic etiologies include diseases with hepatic, renal, and hematologic origins. This encompasses several congenital liver disorders, end-stage renal disease (ESRD), and lymphoproliferative disorders such as Hodgkin's lymphoma. In this paper, an expert panel describes the clinical characteristics, pathophysiology, and therapeutic treatment ladders for chronic pruritus associated with the aforementioned systemic etiologies. Novel therapies are also reviewed. Our aim is to shed light on this unexplored area of pediatric dermatology and instigate further research.

Chronic Kidney Disease-Associated Pruritus

Pruritus is a distressing condition associated with end-stage renal disease (ESRD), advanced chronic kidney disease (CKD), as well as maintenance dialysis and adversely affects the quality of life (QOL) of these patients. It has been reported to range from 20% to as high as 90%. The mechanism of CKD-associated pruritus (CKD-aP) has not been clearly identified, and many theories have been proposed to explain it. Many risk factors have been found to be associated with CKD-aP. The pruritus in CKD presents with diverse clinical features, and there are no set features to diagnose it.The patients with CKD-aP are mainly treated by nephrologists, primary care doctors, and dermatologists. Many treatments have been tried but nothing has been effective. The search of literature included peer-reviewed articles, including clinical trials and scientific reviews. Literature was identified through March 2021, and references of respective articles and only articles published in the English language were included.

The correlation between uremic pruritus and blood lead levels in prevalent hemodialysis patients and its relation to the severity of pruritus using visual analog score

Background

Pruritus is a common and often distressing symptom in patients with chronic kidney disease. Though the pathogenesis of uremic pruritus remains poorly understood, systemic inflammation has presented itself as one of the possible explanations. High blood lead levels (BLLs) have been noted to be associated with inflammation and poor nutritional status in hemodialysis patients. Our aim is to study the relation between blood lead levels and uremic pruritus. This is a cross-sectional study that enrolled 50 patients; all were on regular hemodialysis 3 times per week for at least 6 months. Patients were divided into 2 groups, group 1 (n =10) with no pruritus and group 2 (n=40) with varying degrees of pruritus. Group 2 was further divided according to intensity of pruritus by visual analog score (VAS) into mild (n=10), moderate (n=20), and severe pruritus (n=10).

Results

There was a significant difference in serum lead levels and ferritin levels between groups 1 and 2 (p value < 0.01 and < 0.05, respectively). There was a statistically significant difference in serum lead levels in the groups with varying intensity of pruritus, having higher serum lead levels in patients who exhibited severe pruritus (p value < 0.005) Moreover, a statistically significant relation between elevated blood lead levels and the duration of dialysis was observed in this study.

Conclusion

Uremic pruritus is a multi-factorial phenomenon, and our study showed that blood lead levels in hemodialysis patients might be associated with increased intensity of pruritus.

Effectiveness of a treatment algorithm for hemodialysis-associated pruritus in terms of changes in medications

Background

Hemodialysis-associated pruritus (HAP) is a serious complication that occurs in 60–80% of hemodialysis patients, which not only decreases quality of life but also worsens prognosis. We have developed a treatment algorithm to take a comprehensive cause-specific approach to HAP and used it at our facility since June 2009. In this treatment algorithm, moisturizers and topical steroids are used depending on skin condition and severity of pruritus; administration of nalfurafine hydrochloride is considered in treatment-resistant cases. If pruritus improves, we attempt to taper topical steroids by switching to lower potency or by dose reduction or discontinuation. Here, we examined the effectiveness of the treatment algorithm over 9 years in terms of changes in medications.

Methods

Subjects were hemodialysis patients who received treatment for HAP at our facility: 89 in May 2009 before introduction of the algorithm, and 131 in April 2013, 164 in October 2014, 190 in October 2015, 181 in October 2016, 215 in October 2017, and 224 patients in October 2018 after its introduction. A questionnaire survey was conducted on the presence of pruritus, severity (using a visual analogue scale [VAS] and Shiratori severity scores), frequency, and insomnia due to pruritus. Changes in medications were investigated using medical records and compared.

Results

The proportion of patients with pruritus decreased significantly from 96.6% in 2009 to 66.8% in 2018 (p < 0.001). Median VAS score significantly decreased from 53.0 mm in 2009 to 24.5 mm in 2018 (p < 0.001), and the proportion of patients with insomnia due to pruritus also significantly decreased from 25.8% in 2009 to 2.2% in 2018 (p < 0.001). The proportion of patients who used moisturizers significantly increased from 34.8 to 89.7% (p < 0.001). The proportion of patients receiving topical steroids decreased from 47.2 to 35.7%, but the difference was not significant (p = 0.085).

Conclusions

The treatment algorithm was shown to be useful for improving HAP, but future challenges were identified, including promoting use of lower potency topical steroids or discontinuation. Further prospective studies are required to confirm the role of each treatment intervention in a comprehensive cause-specific approach to HAP.

Chronic kidney disease-associated pruritus significantly impacts on quality of life of patients on haemodialysis and associates with increased levels of serum calcium and phosphorus

PURPOSE OF THE STUDY

Chronic kidney disease-associated pruritus (CKD-aP) is common among patients on maintenance haemodialysis (HD). We performed a study to explore the clinical features of patients with CKD-aP and evaluate the impact of CKD-aP on the quality of life of HD patients.

STUDY DESIGN

Patients who were receiving regular HD over 3 months were recruited. Quality of life was quantified by the Short Form-12 (SF-12) questionnaire. Pruritus was evaluated by the 5D-Itch Scale. Demographic characteristics and biochemical indicators were obtained from the medical record system. Multiple linear regression was used to assess the association between pruritus and targeting factors. The relationship between the scores on the 5D-Itch Scale and SF-12 was analysed using multiple linear regression, adjusted for other factors, to demonstrate the impact of CKD-aP on the quality of life of HD patients.

RESULTS

In total, 269 out of 301 (89.4%) patients accomplished all investigations. The prevalence of CKD-aP in our cohort was 40.9%. Age (B=0.339, p=0.042), treatment with haemoperfusion (B=1.853, p=0.018), and serum level of calcium (B=3.566, p=0.008) and phosphorus (B=1.543, p=0.002) were independently associated with pruritus. Score on the 5D-Itch Scale negatively impacted on physical component summary (B=-0.778, p<0.001) and mental component summary (B=-0.675, p<0.001).

CONCLUSIONS

Pruritus significantly aggravates the quality of life of HD patients. Irregularity in the metabolism of calcium and phosphorus may partially explain the mechanism of CKD-aP. More effective treatment of CKD-MBD may help to prevent pruritus and improve patients' mental and physical health conditions.

Self-reported Pruritus and Clinical, Dialysis-Related, and Patient-Reported Outcomes in Hemodialysis Patients

RATIONALE & OBJECTIVE

Chronic kidney disease (CKD)-associated pruritus, generalized itching related to CKD, affects many aspects of hemodialysis patients' lives. However, information regarding the relationship between pruritus and several key outcomes in hemodialysis patients remains limited.

STUDY DESIGN

Prospective cohort.

SETTING & PARTICIPANTS

23,264 hemodialysis patients from 21 countries in the Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 4 to 6 (2009-2018).

EXPOSURE

Pruritus severity, based on self-reported degree to which patients were bothered by itchy skin (5-category ordinal scale from "not at all" to "extremely").

OUTCOMES

Clinical, dialysis-related, and patient-reported outcomes.

ANALYTICAL APPROACH

Cox regression for time-to-event outcomes and modified Poisson regression for binary outcomes, adjusted for potential confounders.

RESULTS

The proportion of patients at least moderately bothered by pruritus was 37%, and 7% were extremely bothered. Compared with the reference group ("not at all"), the adjusted mortality HR for patients extremely bothered by pruritus was 1.24 (95% CI, 1.08-1.41). Rates of cardiovascular and infection-related deaths and hospitalizations were also higher for patients extremely versus not at all bothered by pruritus (HR range, 1.17-1.44). Patients extremely bothered by pruritus were also more likely to withdraw from dialysis and miss hemodialysis sessions and were less likely to be employed. Strong monotonic associations were observed between pruritus severity and longer recovery time from a hemodialysis session, lower physical and mental quality of life, increased depressive symptoms, and poorer sleep quality.

LIMITATIONS

Residual confounding, recall bias, nonresponse bias.

CONCLUSIONS

Our findings demonstrate how diverse and far-reaching poor outcomes are for patients who experience CKD-associated pruritus, specifically those with more severe pruritus. There is need for change in practice patterns internationally to effectively identify and treat patients with pruritus to reduce symptom burden and improve quality of life and possibly even survival.

An evaluation of difelikefalin as a treatment option for moderate-to-severe pruritus in end stage renal disease

Introduction: Chronic kidney disease-associated pruritus (CKD-aP), or uremic pruritus, is a severely distressing condition that occurs in greater than 60% of patients undergoing dialysis. However, there are currently no FDA approved treatments for CKD-aP in the United States or Europe. Difelikefalin (DFK) is a kappa opioid receptor agonist with limited central nervous system (CNS) penetration that aims to fill this void by effectively and safely reducing itch in these patients.Areas covered: Through a review of the current literature (using PubMed and Google Scholar keyword searches of difelikefalin, CR845, pruritus, itch, opioids, hemodialysis, chronic kidney disease, uremic pruritus), the authors review DFK's mechanism of action and use published clinical trial data to evaluate its effectiveness in treating CKD-aP both individually and comparatively to other treatment alternatives.Expert opinion: DFK's IV formulation seems to provide safe, rapid-acting and effective itch reduction in hemodialysis patients without many of the negative mu opioid receptor (MOR)- or CNS- related side effects or drug-drug interactions of other currently available opioids. Its administration through IV bolus immediately after dialysis sessions at dialysis centers also increases availability to and ease of drug scheduling for this target population.

Dynamic not isometric training blunts osteo-renal disease and improves the sclerostin/FGF23/Klotho axis in maintenance hemodialysis patients: a randomized clinical trial

This study compared the effectiveness of dynamic resistance training (DRT) versus isometric RT (IRT) on osteogenesis and hormonal mechanisms involved in maintenance hemodialysis (MHD) patients. One hundred and ninety-three MHD patients were randomized into three groups: control (CTL) (n = 60), DRT (n = 66), and IRT (n = 67). A first visit was required for an anamnesis to evaluate the number of medications, biochemical, and anthropometric measurements (dialysis adequacy, creatinine, urea, body mass, height, and body mass index). Grip strength, bone mineral density (BMD), and renal-bone markers were assessed pre- and postprotocol. The DRT and IRT training was 6 mo with a frequency of three times per week, on alternate days. Each training session consisted of three sets of 8 to 12 repetitions at lower and moderate intensities. Both training sessions were prescribed approximately 1 h prior to dialysis. Statistical significances were adopted with P < 0.05. There was a greater dropout in the IRT group (24%) as compared with the DRT group (14%), which in turn had less adverse clinical effects (67%, 24%, and 61% for CTL, DRT, and IRT, respectively). DRT promoted gains in BMD in different body locations, in addition to increasing pro-osteogenic factors (Klotho and calcitriol) and reducing those related to bone loss, such as sclerostin, FGF23, and PTH. There was an improvement in Ca × PO₄³ for DRT, whereas these benefits did not occur in the IRT group (P < 0.05). These novel findings suggest that the DRT generates biopositive adaptations in bone tissue in MHD and can be used as a nonpharmacological strategy to improve BMD.NEW & NOTEWORTHY This study shows, for the first time, the effect of dynamic and isometric resistance training on bone mineral density in hemodialysis patients, providing a new understanding of the possible participation of the sclerostin/FGF23/Klotho axis, vitD, PTH, and calcium × phosphate product in this process. However, isometric resistance training may not be sufficient to induce these benefits. Therefore, this study supports the potential therapeutic role of dynamic resistance training counteracting chronic kidney disease-mineral and bone disorder.

Emotional distress and adjustment in patients with end-stage kidney disease: A qualitative exploration of patient experience in four hospital trusts in the West Midlands, UK

Objectives

To explore patient perceptions and experiences of mild-to-moderate emotional distress and the support offered by kidney units to patients with end-stage kidney disease.

Methods

In-depth, semi-structured qualitative interviews with patients (n = 46) being treated for end-stage kidney disease in four hospital Trusts, with data analysed thematically.

Results

Patients described multiple sources of distress and talked about the substantial burden that emotional challenges raised for their ability to manage their condition and develop coping strategies. Many patients did not feel it appropriate to disclose their emotional issues to staff on the kidney unit, due to a perceived lack of time for staff to deal with such issues, or a perception that staff lacked the necessary skills to provide resolution. Five themes were identified from the patient interviews, broadly related to patients’ experience of distress, and the support offered by the kidney unit: i) the emotional burden that distress placed on patients; ii) patients’ relationship with the treatment for their condition; iii) strategies for coping and adjustment; iv) patient-staff interactions and the support offered by the kidney unit, and v) the mediating impact of the treatment environment on patient experience of distress and their ability to raise emotional issues with staff.

Conclusions

Many patients felt unprepared for the likelihood of experiencing emotional issues as part of their condition, for which pre-dialysis education could help in managing expectations, along with support to help patients to develop appropriate coping strategies and adjustments. These findings demonstrate the importance of recognising patient distress and ensuring that talking about distress becomes normalised for patients with end-stage kidney disease.

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

Purpose of review:

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

Sources of information:

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

Methods:

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

Key findings:

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

Limitations:

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

Implications:

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

No significant relation of proinflammatory slanDCs with uremic pruritus

The pathogenesis of the pruritus associated with chronic kidney disease-(CKD-aP) is not completely understood. Endocrine, metabolic, neuropathic, and inflammatory disorders were suspected to be the origin of CKD-aP. Based on the hypothesis which suggests that deregulated systemic inflammation may play a crucial role in CKD-a, we investigated the potential relation of an inflammatory monocyte subset (slanDCs) with CKD-aP. Itch questionnaire, visual analogue scale (VAS)-scoring, and Dermatology Life Quality Index (DQLI) were applied for the characterization of itch sensation. VAS-scoring was re-evaluated after 6 months. Monocytes were flow-cytometrically categorized into classical, intermediate, and non-classical subsets. slanDCs are part of the non-classical monocyte subpopulation. Sixty-six hemodialysis patients (CKD5-D) were screened of whom 43 met the study inclusion criteria. In all, 46.5% of patients were scored pruritus-positive (CKD-aP+). CKD-aP severity level of patients was moderate at the start of the study (VAS 5.3 ± 2.5) and remained unchanged after 6 months (VAS: 5.2 ± 1.9, P < 0.757). Thirty percent of patients were affected with mild, 30.0% with moderate, and 35.0% with severe itchiness. In contrast to all other factors tested solely slanDC showed a weak correlation to VAS-score (r = 0.41, P = 0.07). slanDC frequencies between CKD5-D patients with and without itch sensation, however, were not significantly different. Endocrine problems appeared to influence CKD-aP. CKD-aP + patients had significantly higher L-thyroxin supplementation than CKD-aP- (50.0% vs 8.7%, P < 0.005). A binary logistic regression model confirmed the significance of L-thyroxin medication on chronic itch problems of our CKD5-D patients ( P < 0.007). There is no clear evidence that slanDCs are related to uremic pruritus. Therefore, other factors underlie the pathophysiology of CKD-aP.