Uremic pruritus: roles of parathyroid hormone and substance P

The factors that are associated with itching in chronic kidney patients and evaluation of itching with the 5d itch scale

OBJECTIVE

Uremic pruritus is a distressing complication of chronic kidney disease (CKD), associated with mortality, and negatively impacts quality of life. The 5D-Itch Scale (5D-IS) is an easy-to-apply technique that evaluates 5 different dimensions of itching such as duration, severity, course, disability, and prevalence. We aimed to investigate the prevalence of itching in different CKD stages using the 5D-IS and to investigate the factors associated with itching in CKD patients.

MATERIALS AND METHODS

5D-IS was used to evaluate itching in chronic hemodialysis (HD) and Stage 3-5 CKD patients. Total itching score and sub-scores consist of duration, severity, course, disability and distribution were obtained. Itching scores and prevalence according to CKD stages were investigated. Also the relationships between itching scores and some laboratory and clinical parameters such as iPTH, Ca, P, CRP levels were examined.

RESULTS

158 CKD patients included in the study included (110 Stage 3-5 and 48 HD). The frequency of itching was higher in HD patients than in predialysis patients (62.5% vs 46.4%; p = 0.04). The total itching score increased along with CKD stages 3 to 5 (7.75 ± 3.39, 7.82 ± 4.11 and 9.08 ± 5.12 respectively; p = 0.14). The severity, duration and course scores of itching were similar between the groups, but the distribution scores increased as the CKD stage increased. The laboratory and clinical characteristics of patients with and without itching were not different. Even if a significant positive correlation was detected between the parathyroid hormone levels and both the total 5D-IS scores and all of the sub-scores, Ca and P values were not correlated with itching scores. In the multiple regression analysis, the only parameter that had an effect on the total 5D-IS Score was the parathyroid hormone level.

CONCLUSION

In CKD, itching affects 40-70% of patients from the early stages. As the CKD stage increases, itching spreads throughout the body. The only parameter that seems to be associated with itching is the PTH level.

Data independent acquisition reveals in-depth serum proteome changes in uremic pruritus

Introduction: Uremic pruritus (UP) is a prevalent symptom in patients suffering from uremia, yet its underlying etiology and mechanisms remain incompletely elucidated. Given the significant incidence of UP, identifying specific alterations in proteins present in the blood of UP patients could offer insights into the potential biological pathways associated with UP and facilitate the exploration of biomarkers. Methods: In this study, we employed LC-MS/MS-based data-independent acquisition (DIA) mode to analyze serum samples obtained from 54 UP patients categorized as DKD-UP, HN-UP, and GN-UP (n = 18 for each subgroup), along with 18 uremic patients without pruritus (Negative) and 18 CKD patients without pruritus (CKD). Through DIA mode analysis, a total of 7075 peptides and 959 proteins were quantified. Within these, we identified four upregulated and 13 downregulated Differentially Expressed Proteins (DEPs) in DKD-UP versus Negative, five upregulated and 22 downregulated DEPs in HN-UP versus Negative, and three upregulated and 23 downregulated DEPs in GN-UP versus Negative. Furthermore, we conducted an intersection analysis of the DEPs across these three comparison groups to derive a set of common DEPs (COMP). Subsequently, a total of 67 common DEPs were identified in the three UP groups when compared to the CKD group, with 40 DEPs showing upregulation and 27 DEPs displaying downregulation. Results: Following Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Protein-Protein Interaction (PPI) analyses, we observed that the DEPs distinguishing UP from CKD were primarily associated with mitochondrial function (MT-CYB, PRDX2, TOMM22), inflammation (CD59, CSF1), renal injury (WFDC2), and neural function (CAP1, VGF). Discussion: Our findings contribute to a potential molecular comprehension of UP pathogenesis, shedding light on the identification of these DEPs as plausible biomarkers for UP.

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.

Pathogenesis and Treatment of Pruritus Associated with Chronic Kidney Disease and Cholestasis

Itching is an unpleasant sensation that provokes the desire to scratch. In general, itching is caused by dermatologic diseases, but it can also be caused by systemic diseases. Since itching hampers patients' quality of life, it is important to understand the appropriate treatment and pathophysiology of pruritus caused by systemic diseases to improve the quality of life. Mechanisms are being studied through animal or human studies, and various treatments are being tested through clinical trials. We report current trends of two major systemic diseases: chronic kidney disease and cholestatic liver disease. This review summarizes the causes and pathophysiology of systemic diseases with pruritus and appropriate treatments. This article will contribute to patients' quality of life. Further research will help understand the mechanisms and develop new strategies in the future.

Uremic pruritus: pathophysiology, clinical presentation, and treatments

Uremic pruritus is one of the most common and bothersome symptoms in patients with end-stage renal disease. Most patients with uremic pruritus experience a prolonged and relapsing course and significant impairments of quality of life. The pathophysiology of uremic pruritus is not completely understood. A complex interplay among cutaneous biology and the nervous and immune systems has been implicated, with the involvement of various inflammatory mediators, neurotransmitters, and opioids. Uremic pruritus treatment outcomes are often unsatisfactory. Clinical trials have mostly been small in scale and have reported inconsistent results. Recent evidence shows that gabapentinoids, nalfurafine, and difelikefalin are effective for relieving uremic pruritus in hemodialysis patients. This review provides an overview of the epidemiology and proposed mechanisms of uremic pruritus, then highlights the manifestations of and clinical approach to uremic pruritus. Current evidence regarding treatment options, including topical treatments, treatment of underlying disease, phototherapy, and systemic treatments, is also outlined. With a better understanding of uremic pruritus, more therapeutic options can be expected in the near future.

Unravelling the pathophysiology of chronic kidney disease-associated pruritus

For decades, itch related to chronic kidney disease (CKDaP) has been a clinical problem, but the aetiology and pathophysiology of CKDaP are still not yet fully understood—currently the underlying pathophysiological mechanisms are thought to be multifactorial. As new therapeutic targets have recently been identified and clinical trials have shown promising results, our current understanding of the interrelationships has expanded significantly. Here we review the pathophysiology and recent findings on modulation and sensitization of itch contributing to the development of CKDaP, covering hypothesis regarding immune system dysfunction, metabolic changes, uremic toxin deposition, peripheral neuropathy and imbalances in the endogenous opioid system.

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.

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.

Associated Factors With Uremic Pruritus in Chronic Hemodialysis Patients: A Single-Center Observational Study

Background and objectives

Uremic pruritus is a recurrent and delicate manifestation in patients suffering from end-stage renal disease. It is a consequence of multiple factors, primarily comprising of metabolic factors and complement activation along with interleukins. The objective of our study was to find out the associated factors of uremic pruritus in chronic hemodialysis patients. The secondary aim was to obtain cut-off values of all the markers predicting pruritus.

Materials and methods

A cross-sectional observational study was conducted in the nephrology department of a tertiary care hospital including 135 patients. The current occurrence of pruritus was diagnosed on the basis of a validated and reliable scale of pruritus among chronic kidney disease (CKD) patients in the local language. Multivariate logistic regression and receiver operating characteristic analysis were conducted to decipher the required objectives.

Results

Study participants had a mean age of 56.29 ± 10.51 years with 56.3% males and 43.7% females. Hypertension was frequent comorbidity (75.6%) followed by diabetes (51.9%). Mean body mass index (BMI), duration of CKD diagnosis, and hemodialysis onset were 26.55 ± 5.37 kg/m², 6.58 ± 3.65 years, and 3.32 ± 2.09 years respectively. Pruritus was reported in 37.0% of the study participants. On multivariate logistic regression, presence of skin allergy (aOR: 8.100 [2.926-22.420], p<0.001), phosphate >4.5 mg/dL (aOR: 3.889 [1.118-15.532], p=0.033), female gender (aOR: 3.592 [1.337-9.655], p=0.011), albumin <3.5 g/dL (aOR: 2.987 [1.156-7.716], p=0.024) and potassium >5.1 mEq/L (aOR: 2.934 [1.030-8.355], p=0.044) were found significantly associated with pruritus.

Conclusion

Many factors were linked to pruritus in hemodialysis patients in the current study. The current study also significantly correlated certain factors with pruritus independently.

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.

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

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

Interventions for itch in people with advanced chronic kidney disease

BACKGROUND

Itch in patients with chronic kidney disease (CKD) is common, often very distressing and associated with depression, reduced quality of life, and increased death. The most common first-line treatment has been the use of antihistamines despite the lack of substantial evidence for its use for uraemic itch. Few recommendations and guidelines exist for treatment.

OBJECTIVES

We aimed to determine: 1) the benefits and harms (both absolute and relative) of all topical and systemic interventions for the treatment of uraemic itch, either alone or in combination, when compared with placebo or standard care; and, 2) the dose strength or frequency, stage of kidney disease or method of dialysis used (where applicable) in cases where the effects of these interventions vary depending on co-interventions.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 17 December 2019 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) in adults with CKD stages 4 or 5 comparing treatments (pharmacological, topical, exposure, dialysis modality) for CKD associated itch to either placebo or other established treatments.

DATA COLLECTION AND ANALYSIS

Two authors independently abstracted study data and assessed study quality. Data were analysed using a random effects meta-analysis design estimating the relative effects of treatment versus placebo. Estimates of the relative effects between treatments are included where possible. For continuous measures of severity of itch up to three months, mean difference (MD) or standardised mean difference (SMD) were used. When reported, adverse effects were tabulated. The certainty of the evidence was estimated using GRADE.

MAIN RESULTS

Ninety-two RCTs, randomising 4466 participants were included. Fifty-eight studies (3285 participants) provided sufficient data to be meta-analysed. Of these, 30 compared an intervention to a placebo or control. The 10 cm Visual Analogue Scale (VAS) was the dominant instrument utilized for itch reporting and the Duo score was used in a minority of studies. GABA analogues including, gabapentin and pregabalin, reduce itch in patients with CKD (5 studies, 297 participants: 4.95 cm reduction, 95% CI 5.46 to 4.44 lower in VAS compared to placebo; high certainty evidence). Kappa opioid agonists, including nalfurafine also reduced itch in this population (6 studies, 661 participants: 1.05 cm reduction, 95% CI 1.40 to 0.71 lower in VAS compared to placebo; high certainty evidence). Ondansetron had little or no effect on itch scores (3 studies, 183 participants: 0.38 cm reduction, 95% CI 1.04 lower to 0.29 higher in VAS compared to placebo; high certainty evidence). Reduction in the severity of itch was reported with oral montelukast, turmeric, zinc sulfate and topical capsaicin. For all other interventions, the certainty of the evidence was low to moderate, and the interventions had uncertain effects on uraemic pruritus. Six studies have disclosed significant financial support from their respective manufacturers, six were affected by lack of blinding, and 11 studies have 15 participants or less. Older, smaller RCTs often failed to follow intention-to-treat protocols with unexplained dropouts after randomisation. Adverse effects were generally poorly and inconsistently reported across all RCTs. No severe adverse events were reported for any intervention.

AUTHORS' CONCLUSIONS

The RCTs of this meta-analysis contain a large array of interventions with a diverse set of comparators. For many interventions, trials are sparse. This served to make informative meta-analysis challenging. Of all treatments for uraemic pruritus, gabapentinoids (gabapentin and pregabalin) were the most studied and show the greatest reduction in itch scores. Further RCTs, even of the scale of the largest trials included in this review, are unlikely to significantly change this finding. Kappa-opioid agonists (mainly nalfurafine) also may reduce itch, but indirect comparison suggests a much more modest effect in comparison to GABA analogues. Evidence for oral montelukast, turmeric, zinc sulfate, and topical capsaicin also showed an itch score reduction. However, these reductions were reported in small studies, and warrant further investigation. Ondansetron did not reduce itch. It is somewhat unlikely that a further study of ondansetron will change this result.

Complementary and alternative medicine therapies for uremic pruritus - A systematic review of randomized controlled trials

INTRODUCTION

Uremic pruritus (UP) is one of the most bothersome symptoms among chronic kidney disease (CKD) patients. The pathophysiology of UP remains elusive, resulting in limited treatment options. The inability of standard medical treatments to provide effective relief has piqued interest in complementary and alternative medicine (CAM).

METHODOLOGY

A systematic review of randomized controlled trials (RCTs) summarizing the efficacy and safety profile of CAM used for UP in CKD patients was performed. CAM interventions were classified using categories proposed by the National Center for Complementary and Integrative Health. The efficacy of each CAM was determined from changes in UP severity and all reported adverse effects were extracted.

RESULTS

Of 5242 articles screened, 34 RCTs were included, with 15 (44.1 %) studies having a sample size greater than 50. The studies considered 21 treatments including omega-3 fatty acid supplementation (n=5), acupuncture (n=5), topical capsaicin (n=4) and acupressure (n=3). Acupuncture, acupressure and topical capsaicin were shown to be effective in improving uremic pruritus. Interventions which include oral omega-3 fatty acid and zinc supplementation demonstrated mixed efficacy. Other therapies such as evening primrose oil, turmeric, vitamin B3, vitamin D and thermal therapy were not effective for treatment of UP. Common adverse effects reported with topical capsaicin included mild burning sensations (50.0-88.2 %) or erythema (6.7-22.7%) while that of acupuncture included soreness (7.5 %), bleeding (6.0-7.5%) and hematoma (1.9 %).

CONCLUSIONS

Acupuncture, acupressure and topical capsaicin have the largest body of evidence for efficacy in the treatment of UP. Larger and higher quality RCTs are required to examine the efficacy and safety of promising CAM.

Uremic pruritus and long-term morbidities in the dialysis population

Background

Uremic pruritus (UP) is a multifactorial problem that contributes to low quality of life in dialysis patients. The long-term influences of UP on dialysis patients are still poorly understood. This study aims to elucidate the contribution of UP to long-term outcomes.

Materials and method

We used the Taiwan National Health Insurance Research Database to conduct this study. Patients on chronic dialysis were included and divided into UP and non-UP groups according to the long-term prescription of antihistamine in the absence of other indications. The outcomes include infection-related hospitalization, catheter-related infection, major adverse cardiac and cerebrovascular events (MACCE) and parathyroidectomy.

Results

After propensity score matching, 14,760 patients with UP and 29,520 patients without UP were eligible for analysis. After a mean follow-up of 5 years, we found that infection-related hospitalization, MACCE, catheter-related infection, heart failure and parathyroidectomy were all slightly higher in the UP than non-UP group (hazard ratio: 1.18 [1.16–1.21], 1.05 [1.01–1.09], 1.16 [1.12–1.21], 1.08 [1.01–1.16] and 1.10 [1.01–1.20], respectively). Subgroup analysis revealed that the increased risk of adverse events by UP was generally more apparent in younger patients and patients who underwent peritoneal dialysis.

Conclusion

UP may be significantly associated with an increased risk of long-term morbidities.

CKD-Associated Pruritus: New Insights Into Diagnosis, Pathogenesis, and Management

Chronic kidney disease–associated pruritus (CKD-aP) is a common, troubling and in some cases debilitating problem for patients with CKD and end-stage renal disease. Despite a prevalence rate of approximately 20% in CKD and 40% in end-stage renal disease, and a clear association with poorer psychosocial and medical outcomes, this condition is often underreported by patients and overlooked by health care providers. This is likely due, in part, to uncertainty regarding its pathogenesis and treatment. Most commonly, CKD-aP is attributed to toxin build-up, peripheral neuropathy, immune system dysregulation, or opioid dysregulation. Prior treatment studies of CKD-aP have targeted these potential etiologies but have been limited by noncontrolled design, small sample size, and non-uniform definitions of CKD-aP. Recently, several large, randomized controlled trials targeting opioid dysregulation have yielded promising results. These trials have spurred new hope for understanding and treating this condition.

Development and Validation of a Uremic Pruritus Treatment Algorithm and Patient Information Toolkit in Patients With Chronic Kidney Disease and End Stage Kidney Disease

CONTEXT

Uremic pruritus (UP) affects up to half of all patients with kidney disease and has been independently associated with poor patient outcomes. UP is a challenging symptom for clinicians to manage as there are no validated guidelines for its treatment.

OBJECTIVES

The study aimed to develop and validate an algorithm and patient information toolkit for the treatment of UP in patients with kidney disease.

METHODS

The study involved a literature search and development of an initial draft algorithm, followed by content and face validation of this algorithm. Validation entailed three rounds of interviews with six nephrology clinicians per round. Participants assessed the relevance of each component of the algorithm and then rated a series of statements on a scale of 1-5 to assess face validity of the algorithm. After each round, the content validity index (CVI) of each algorithm component was calculated, and the algorithm was revised by the study team in response to findings. This process was followed by a second study that developed and validated a patient information pamphlet and video.

RESULTS

Algorithm validation participants were affiliated with three institutions and included seven physicians, four registered nurses, three nurse practitioners, three pharmacists, and a dietician. The average CVI of the algorithm components across all three rounds was 0.89, with 0.80 commonly cited as the lower acceptable limit for content validation. More than 78% of participants rated each face validity statement as "Agree" or "Strongly Agree". For the patient information tools, five clinicians and 15 patients were included in validation. The average CVI was 1.00 for both tools, and the average face validity was 92%.

CONCLUSION

A treatment algorithm and patient information toolkit for managing UP in patients with kidney disease were developed and validated through expert review. Further research will be conducted on implementation of the treatment algorithm and evaluating patient-reported outcomes.

Symptoms of Secondary Hyperparathyroidism in Patients Receiving Maintenance Hemodialysis: A Prospective Cohort Study

RATIONALE & OBJECTIVE

Although multiple lines of evidence suggest a negative impact of secondary hyperparathyroidism on patients with kidney failure treated by hemodialysis, it is uncertain whether patients can detect associated symptoms. The objective was to determine whether changes in parathyroid hormone (PTH) levels are associated with changes in symptoms within this patient population.

STUDY DESIGN

Prospective cohort.

SETTING & PARTICIPANTS

165 adults with hyperparathyroidism secondary to kidney failure diagnosed, a range of dialysis vintages, and receiving regular hemodialysis from a US single-provider organization.

EXPOSURE

Change in PTH levels over 24 weeks.

OUTCOMES

19 putative symptoms of secondary hyperparathyroidism measured up to 4 times using a self-administered questionnaire that assessed severity on a 5-level ordinal scale.

ANALYTICAL APPROACH

Longitudinal associations between changes in PTH levels and symptom severity were assessed using generalized additive models.

RESULTS

The 165 participants studied represented 81% of enrollees (N=204) who had sufficiently complete data for analysis. Mean age was 56 years and 54% were women. Increases in PTH levels over time were associated (P<0.1) with worsening of bone aches and stiffness, joint aches, muscle soreness, overall pain, itchy skin, and tiredness, and the effects were more pronounced with larger changes in PTH levels.

LIMITATIONS

Findings may have been influenced by confounding by unmeasured comorbid conditions, concomitant medications, and multiple testing coupled with a P value threshold of 0.10.

CONCLUSIONS

In this exploratory study, we observed that among patients with secondary hyperparathyroidism, increases in PTH levels over time were associated with worsening of 1 or more cluster of symptoms. Replication of these findings in other populations is needed before concluding about the magnitude and shape of these associations. If replicated, these findings could inform clinically useful approaches for measuring patient-reported outcomes related to secondary hyperparathyroidism.

Vegetarian diet may ameliorate uremic pruritus in hemodialysis patients

Objectives: Systemic inflammation has been reported to be associated with uremic pruritus (UP). Although a vegetarian diet can reduce systemic inflammation in hemodialysis patients, the effect of vegetarian diet on UP is not clear. The purpose of the study was to know the possible effects of vegetarian diet on UP.

Methods: A cross-sectional study was done to compare the severity of UP and blood levels of systemic inflammatory markers between vegetarian and non-vegetarian hemodialysis patients. Six non-vegetarian patients with uremic pruritus changed their non-vegetarian diet to vegetarian diet for 2 months. Visual Analogue Scale (VAS) and pruritus score (PS) were used to measure the UP severity. The serum high-sensitivity C-reactive protein (hs-CRP), and interleukin-2 (IL-2) were used as markers of inflammation.

Results: Both the median VAS scores (p = .043) and the median PS scores (p < .001) were lower in the Vegetarian than in the non-vegetarian group. The median values of hs-CRP in Vegetarian were lower than that for the non-vegetarian (p = .020). The median value of IL-2 was also lower in Vegetarian than that of the non-vegetarian (p = .016). There were 6 non-vegetarian patients shift to vegetarian for 2 months. The pruritus score improved and IL-2 level decreased after change to vegetarian diet.

Conclusion: We concluded that vegetarian diet might be associated with the amelioration of the uremic pruritus severity in hemodialysis patients.

Dermatologic manifestations in end stage renal disease

Skin manifestations are commonly seen in end stage renal disease (ESRD). Skin involvement in this population can be extensive and dramatically worsen quality of life. Close observation of the skin and nails of ESRD patients by clinicians allows for timely diagnosis and treatment, which ultimately improves quality of life and reduces mortality. In this article we focus on the cutaneous changes most commonly seen in ESRD patients. PubMed/Medline database search was done for published literature on skin manifestations in ESRD patients. All the available literature was reviewed and relevant articles were used to discuss about clinical features, pathogenesis, histology and treatment of each skin disorder in ESRD patients. Most commonly encountered skin manifestations in patients with ESRD are pruritus, xerosis, pigmentation changes, nail changes, perforating disorders, calcifying disorders, bullous dermatoses and nephrogenic systemic fibrosis. Skin manifestations in ESRD can be difficult to treat and multiple comorbidities in this patient population can exacerbate these disorders. Many of the treatment options are experimental with evidence largely derived from the case reports and small clinical trials. More large-scale trials are needed to firmly establish evidence based treatment guidelines. Prompt evaluation and management of these disorders improve morbidity and quality of life in ESRD patients.

Research progress of capsaicin responses to various pharmacological challenges

Capsaicin, a well known vanilloid, has shown evidence of an ample variety of biological effects which make it the target of extensive research ever since its identification. In spite of the fact that capsaicin causes health hazards in quite a few ways, yet, the verity cannot be ignored that capsaicin has several therapeutic implications. In patients with hypersensitive bladders, vesical instillation of 1 mM capsaicin markedly improved urinary frequency and urge incontinence. Again, administration of capsaicin favors an augmentation in lipid mobilization and a decrease in adipose tissue mass. Topical capsaicin cream as well decreases postsurgical neuropathic pain and is preferred by patients over a placebo among other therapies. Several in vitro studies have revealed that capsaicin results in growth arrest in some transformed cell lines. Furthermore, capsaicin has been proven to be an undeniably exciting molecule and remains a valuable drug for alleviating pain and itch. It has been recognized that capsaicinoids are the most potential agonists of capsaicin receptor (TRPV1). However, vanilloids could exert the beneficial effects not only through the receptor-dependent pathway but also through the receptor-independent one. The involvement of serotonin, neuropeptide Substance P and somatostatin in the pharmacological actions of capsaicin has been expansively investigated. Better understanding of the established TRPV1 receptor mechanism as well as exploring other possible receptor mechanism may publicize other new clinical efficacies of capsaicin. Further, clinical studies are required in several of these conditions to establish the efficacy of capsaicin.

Treatment of Uremic Pruritus: A Systematic Review

BACKGROUND

Uremic pruritus is a common and burdensome symptom afflicting patients with advanced chronic kidney disease (CKD) and has been declared a priority for CKD research by patients. The optimal treatments for uremic pruritus are not well defined.

STUDY DESIGN

Systematic review.

SETTING & POPULATION

Adult patients with advanced CKD (stage ≥ 3) or receiving any form of dialysis.

SELECTION CRITERIA FOR STUDIES

PubMed, CINAHL, Embase, International Pharmaceutical Abstracts, Scopus, Cochrane Library, and ClinicalTrials.gov from their inception to March 6, 2017, were systematically searched for randomized controlled trials (RCTs) of uremic pruritus treatments in patients with advanced CKD (stage ≥ 3) or receiving any form of dialysis. 2 reviewers extracted data independently. Risk of bias was assessed using the Cochrane Collaboration risk-of-bias tool.

INTERVENTION

Any intervention for the treatment of uremic pruritus was included.

OUTCOMES

A quantitative change in pruritus intensity on a visual analogue, verbal rating, or numerical rating scale.

RESULTS

44 RCTs examining 39 different treatments were included in the review. These treatments included gabapentin, pregabalin, mast cell stabilizers, phototherapy, hemodialysis modifications, and multiple other systemic and topical treatments. The largest body of evidence was found for the effectiveness of gabapentin. Due to the limited number of trials for the other treatments included, we are unable to comment on their efficacy. Risk of bias in most studies was high.

LIMITATIONS

Heterogeneity in design, treatments, and outcome measures rendered comparisons difficult and precluded meta-analysis.

CONCLUSIONS

Despite the acknowledged importance of uremic pruritus to patients, with the exception of gabapentin, the current evidence for treatments is weak. Large, simple, rigorous, multiarm RCTs of promising therapies are urgently needed.

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

Chronic kidney disease-associated pruritus (CKD-aP) is a distressing, often overlooked condition in patients with CKD and end-stage renal disease. It affects ~40% of patients with end-stage renal disease and has been associated with poor quality of life, poor sleep, depression, and mortality. Prevalence estimates vary based on the instruments used to diagnose CKD-aP, and standardized diagnostic instruments are sorely needed. Treatment studies have often yielded conflicting results. This is likely related to studies that are limited by small sample size, flawed designs, and nonstandardized diagnostic instruments. Several large well-designed treatment trials have recently been completed and may soon influence CKD-aP management.

Pharmacological interventions for pruritus in adult palliative care patients

BACKGROUND

This is an update of the original Cochrane review published in 2013 (Issue 6). Pruritus occurs in patients with disparate underlying diseases and is caused by different pathologic mechanisms. In palliative care patients, pruritus is not the most prevalent but is one of the most puzzling symptoms. It can cause considerable discomfort and affects patients' quality of life.

OBJECTIVES

To assess the effects of different pharmacological treatments for preventing or treating pruritus in adult palliative care patients.

SEARCH METHODS

For this update, we searched CENTRAL (the Cochrane Library), and MEDLINE (OVID) up to 9 June 2016 and Embase (OVID) up to 7 June 2016. In addition, we searched trial registries and checked the reference lists of all relevant studies, key textbooks, reviews and websites, and we contacted investigators and specialists in pruritus and palliative care regarding unpublished data.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) assessing the effects of different pharmacological treatments, compared with a placebo, no treatment, or an alternative treatment, for preventing or treating pruritus in palliative care patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the identified titles and abstracts, performed data extraction and assessed the risk of bias and methodological quality. We summarised the results descriptively and quantitatively (meta-analyses) according to the different pharmacological interventions and the diseases associated with pruritus. We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created 10 'Summary of findings' tables.

MAIN RESULTS

In total, we included 50 studies and 1916 participants in the review. We added 10 studies with 627 participants for this update. Altogether, we included 39 different treatments for pruritus in four different patient groups.The overall risk of bias profile was heterogeneous and ranged from high to low risk. However, 48 studies (96%) had a high risk of bias due to low sample size (i.e. fewer than 50 participants per treatment arm). Using GRADE criteria, we downgraded our judgement on the quality of evidence to moderate in seven and to low in three comparisons for our primary outcome (pruritus), mainly due to imprecision and risk of bias.In palliative care participants with pruritus of different nature, the treatment with the drug paroxetine, a selective serotonin reuptake inhibitor, reduced pruritus by 0.78 points (numerical analogue scale from 0 to 10; 95% confidence interval (CI) -1.19 to -0.37; one RCT, N = 48, quality of evidence: moderate) compared to placebo.For participants suffering from uraemic pruritus (UP), gabapentin was more effective than placebo (visual analogue scale (VAS): 0 to 10), mean difference (MD) -5.91, 95% CI -6.87 to -4.96; two RCTs, N = 118, quality of evidence: moderate). The κ-opioid receptor agonist nalfurafine showed amelioration of UP (VAS 0 to 10, MD -0.95, 95% CI -1.32 to -0.58; three RCTs, N = 422, quality of evidence: moderate) and only few adverse events. Moreover, cromolyn sodium relieved UP participants from pruritus by 2.94 points on the VAS (0 to 10) (95% CI -4.04 to -1.83; two RCTs, N = 100, quality of evidence: moderate) compared to placebo.In participants with cholestatic pruritus (CP), data favoured rifampin (VAS: 0 to 100, MD -24.64, 95% CI -31.08 to -18.21; two RCTs, N = 42, quality of evidence: low) and flumecinol (RR > 1 favours treatment group; RR 1.89, 95% CI 1.05 to 3.39; two RCTs, N = 69, quality of evidence: low) and showed a low incidence of adverse events in comparison with placebo. The opioid antagonist naltrexone reduced pruritus for participants with CP (VAS: 0 to 10, MD -2.26, 95% CI -3.19 to -1.33; two RCTs, N = 52, quality of evidence: moderate) compared to placebo. However, effects in participants with UP were inconclusive (percentage difference -12.30%, 95% CI -25.82% to 1.22%, one RCT, N = 32). Furthermore, large doses of opioid antagonists (e.g. naltrexone) could be inappropriate in palliative care patients because of the risk of reducing analgesia.For participants with HIV-associated pruritus, it is uncertain whether drug treatment with hydroxyzine hydrochloride, pentoxifylline, triamcinolone or indomethacin reduces pruritus because the evidence was of very low quality (e.g. small sample size, lack of blinding).

AUTHORS' CONCLUSIONS

Different interventions tended to be effective for CP and UP. However, therapies for patients with malignancies are still lacking. Due to the small sample sizes in most meta-analyses and the heterogeneous methodological quality of the included trials, the results should be interpreted cautiously in terms of generalisability.

Pruritus in Kidney Disease

Pruritus is a common and distressing symptom in patients with chronic kidney disease. The most recent epidemiologic data have suggested that approximately 40% of patients with end-stage renal disease experience moderate to severe pruritus and that uremic pruritus (UP) has a major clinical impact, being associated strongly with poor quality of life, impaired sleep, depression, and increased mortality. The pathogenesis of UP remains largely unclear, although several theories on etiologic or contributing factors have been proposed including increased systemic inflammation; abnormal serum parathyroid hormone, calcium, and phosphorus levels; an imbalance in opiate receptors; and a neuropathic process. UP can present somewhat variably, although it tends to affect large, discontinuous, but symmetric, areas of skin and to be most symptomatic at night. A variety of alternative systemic or dermatologic conditions should be considered, especially in patients with asymmetric pruritus or other atypical features. Treatment initially should focus on aggressive skin hydration, patient education on minimizing scratching, and optimization of the aspects of chronic kidney disease care that are most relevant to pruritus, including dialysis adequacy and serum parathyroid hormone, calcium, and phosphorus management. Data for therapy specifically for UP remain limited, although topical therapies, gabapentin, type B ultraviolet light phototherapy, acupuncture, and opioid-receptor modulators all may play a role.

Laboratory and dialysis characteristics in hemodialysis patients suffering from chronic itch--results from a representative cross-sectional study

BACKGROUND

A representative cross-sectional study showed that chronic itch (lasting for a minimum of 6 weeks) affects 25.2 % (point prevalence) of hemodialysis (HD) patients. Pathophysiology and etiology of chronic itch (CI) in HD are still unclear.

METHODS

We investigated 860 HD patients from a representative randomly selected cluster-sample considering the regional distributions of dialysis units in Germany. The current analyses report comorbidities, laboratory values and dialysis characteristics of HD patients in relation to CI.

RESULTS

Diabetes was the only comorbidity that was associated with the occurrence of itch but interestingly with less CI. Except for creatinine, phosphorus, and parathormone, there were no significant associations between the occurrence and characteristics of CI and any laboratory value. Kt/V was not associated with the presence of CI. Patients dialyzed with polyarylethersulfone-membrane showed significantly more CI in all prevalence estimates and those dialyzed with polysulfone-membrane were significantly less affected by CI.

CONCLUSIONS

Long-term follow-up studies will show if the type of dialysis membrane influences the development of CI in HD patients. It is most likely that several factors e.g. elevated parathormone, origin of end stage renal disease (ESRD), type of dialysis membrane, and a neuropathic component all contribute to the occurrence of CI in HD patients. Future research should consider a multifactorial origin of itch in HD.

Role of Interleukin-2 in Uremic Pruritus Among Attendants of AL-Zahraa Hospital Dialysis Unit

Background:

Uremic pruritus (UP) is a very distressing symptom and remains one of the most frustrating and potentially disabling symptoms in patients with end-stage renal disease (ESRD). Its etiopathogenesis remains unclear and complex. The aim of this study was to investigate the possible role of interleukin-2 (IL-2) in UP, and correlate its level with the severity of itching in ESRD patients.

Patients and Methods:

This study was carried out on 60 patients on maintenance hemodialysis (HD), 30 patients with UP and 30 patients without UP, and 30 apparently healthy age- and sex-matched subjects as controls. Itch intensity was scored as mild, moderate, and severe using five-dimensional itch scale. Some relevant clinical parameters (age, sex, xerosis, presence of neuropathy, duration of dialysis, complete medical history, and history of pruritic skin diseases) and laboratory findings including creatinine, urea, calcium, phosphorus, parathyroid hormone, and serum levels of IL-2 were evaluated.

Results:

In our study, we found a statistically significant difference in IL-2 level between patients and controls. However, there was no statistically significant difference in IL-2 levels between cases with pruritus and cases without pruritus. Also, there was a statistically significant relation between IL-2 level and duration of the disease.

Conclusion:

Further studies are needed to understand the contribution of IL-2 and possibly other cytokines in the pathogenesis of this distressing symptom in ESRD.

Safety of pregabalin among hemodialysis patients suffering from uremic pruritus

Objectives: The aim of this study was to assess the safety and probability of adverse events associated with the use of 75 mg pregabalin post hemodialysis (pHD) among patients with UP. Methods: A cross-sectional study done among the hemodialysis patients suffering from uremic pruritus (UP) Aljaber Kidney Center (AJKC), Al-Ahsa, Eastern Province, Saudi Arabia. Assessment for the safety profile of pregabalin was done using Naranjo’s algorithm. A predictive model was developed using binary multiple logistic regression to explore association of patients’ demographics and risk factors with the occurrence of AEs. Throughout statistical significance level was considered significant at 0.05. Key findings: Assessment of safety of pregabalin revealed that somnolence and dizziness were the two frequent adverse events followed by constipation, weight gain and edema. However, it was noticed that female patients aged less than 50 years were found to be at a higher risk in comparison with men. Moreover, those patients having one comorbid complication (i.e. hypertension or diabetes mellitus alone) were at a higher risk of somnolence, weight gain and dry mouth. Conclusion: Naranjo’s quantification for the possibility and probability of adverse events reflect that all the events were probable. Age, gender and comorbid medical conditions are some of the factors that might have clinical association with the occurrence of the AEs.

Cutaneous abnormalities in patients with end stage renal failure on chronic hemodialysis. A study of 458 patients

BACKGROUND

Cutaneous manifestations occurring in patients with end stage renal failure on hemodialysis are polymorphic and diverse.

OBJECTIVE

The aim of our study was to assess the prevalence and characteristics of different cutaneous manifestations in patients on hemodialysis.

PATIENTS AND METHODS

We led a transverse investigation of all patients on hemodialysis in 12 haemodialysis centres of Sfax (Tunisia). We examined 458 patients (254 men and 204 women). The hemodialysis history ranged from 6 months to 24 years. A total of 394/458 (86%) patients had cutaneous abnormalities. These included pruritus (56.6% of patients), paleness (60.7%), xerosis (52.8%), hyperpigmentation or hypopigmentation (38.4%), venous dilation near the fistula (22.2%), eczema in the fistula area (14.8%), half-and-half nails (13.5%), onychodystrophy (6.1%), subungual hemorrhage (4.5%), leukonychia (4.5%), stomatitis (5.6%), xerostomia (3.2%), gingivitis (2.4%), uremic breath (2.1%), and skin calcificatins (0.4%). Nephrogenic fibrosing dermopathy was not detected in any of our patients.

CONCLUSIONS

Pruritus, paleness, dry skin as well as hyperpigmentation and hypopigmentation are the most frequent skin abnormalities observed in hemodialysis patients. The early recognition of some cutaneous conditions associated with end stage renal failure and hemodialysis may allow early therapeutic intervention and decrease morbidity.

Pruritus in hemodialysis patients: Results from the Japanese Dialysis Outcomes and Practice Patterns Study (JDOPPS)

Pruritus affects many patients undergoing hemodialysis (HD). In this study, pruritus and its relationship to morbidity, quality of life (QoL), sleep quality, and patient laboratory measures were analyzed in a large sample of Japanese patients undergoing HD. Severity of patient-reported pruritus symptoms experienced during a 4-week period was collected from 6480 Japanese patients undergoing HD in three phases of the Dialysis Outcomes and Practice Patterns Study (DOPPS; 1996-2008; 60-65 study facilities/phase). Adjusted linear and logistic regressions were used to identify associations of pruritus with treatment parameters and QoL outcomes. Adjusted Cox regressions examined the influence of pruritus severity on mortality. Moderate to extreme pruritus was experienced by 44% of prevalent patients undergoing HD in the Japanese Dialysis Outcomes and Practice Patterns Study. Many patient characteristics were significantly associated with pruritus, but this did not explain the large differences in pruritus among facilities (20-70%). Pruritus was slightly less common in patients starting HD than in patients on dialysis >1 year. Patients with moderate to extreme pruritus were more likely to feel drained (adjusted odds ratio = 2.2-5.8, P < 0.0001), have poor sleep quality (adjusted odds ratio = 1.9-3.7, P < 0.0001), and have QoL mental and physical composite scores 2.3-6.7 points lower (P < 0.0001) than patients with no/mild pruritus. Pruritus in patients undergoing HD was associated with a 23% higher mortality risk (P = 0.09). The many poor outcomes associated with pruritus underscore the need for better therapeutic agents to provide relief for the 40-50% of prevalent patients undergoing HD substantially affected by pruritus. Pruritus in new patients with end-stage renal disease likely results from uremia or pre-existing conditions (not HD per se), indicating the need to understand development of pruritus before end-stage renal disease.

[Cutaneous manifestations in hemodialysis patients]

BACKGROUND

Hemodialysis patients have frequent and various cutaneous manifestations of often hypothetical pathogenesis. Chronic renal failure (CRF) presents with an array of cutaneous manifestations. The objective was to evaluate the prevalence and nature of cutaneous lesions associated with CRF patients on hemodialysis patients.

PATIENTS AND METHODS

Transversal and observational study of 53 patients with CRF on regular hemodialysis.

RESULTS

There were 28 women and 25 men. Their mean age was 44 year-old. All patients had cutaneous manifestations and 64% complained of dermatological signs. Cutaneous xerosis and pigmentation disorders were found in 96 and 94% of patients, respectively. Other manifestations were pallor (41%), pruritus (20.7%), a diffuse hair loss (35.8%) and nails changes (66%).

COMMENTS

Cutaneous manifestations in hemodialysis patients are frequent polymorphous. Their incidence varies from 50 to 100% of the series. Their knowledge deserves a proper management by both dermatologists and nephrologists to improve the life quality of hemodialysis patients.

Pharmacological interventions for pruritus in adult palliative care patients

BACKGROUND

Pruritus is not the most prevalent but one of the most puzzling symptoms in palliative care patients. It can cause considerable discomfort and has a major impact on patients' quality of life. In the field of palliative care, pruritus is a symptom occurring in patients with disparate underlying diseases and based on different pathologic mechanisms but ending in the same phenomenon. The pathogenesis of pruritus is complex and not fully elucidated. Thus, it is still very difficult to treat pruritus effectively. Evidence-based treatment approaches are needed.

OBJECTIVES

The objective was to evaluate the efficacy of different pharmacological treatments for preventing or treating pruritus in adult palliative care patients.

SEARCH METHODS

A systematic literature search up to January 2012 was performed and it was updated in August 2012. The following databases were searched: The Cochrane Library (CENTRAL, DARE, CDSR) (2012, issue 8 of 12); MEDLINE (1950 to August 2012); EMBASE (1980 to August 2012) and three other databases. In addition, we searched trials registries and checked the reference lists of all relevant studies, key textbooks, reviews, and websites, and contacted investigators and specialists in pruritus and palliative care regarding unpublished data.

SELECTION CRITERIA

We included randomised controlled trials assessing the effects of different pharmacological treatments on preventing or treating pruritus in palliative care patients.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed identified titles and abstracts. Three independent review authors performed assessment of all potentially relevant studies, data extraction, assessment of risk of bias and methodological quality. Results were summarised descriptively according to the different pharmacological interventions and the type of underlying pruritus. Where possible, results were presented in meta-analyses.

MAIN RESULTS

In total, 38 reports comprising 40 studies and 1286 participants were included in the review. Altogether, 30 different treatments for pruritus in four different patient groups were included.The findings of this review indicated that the treatment of pruritus for palliative care patients is challenging and requires an individualistic approach. Results showed that effective therapeutic choices have to be guided by the pathophysiology of the pruritus. Various forms of pruritus occur, especially in the field of palliative care, and sometimes the origin of the pruritus is difficult to determine. Therefore, identifying the underlying cause of pruritus is of prime importance in order to develop tailored treatment plans, even if in palliative care the treatment is focused towards the symptom and not necessarily the underlying disease.Results show that in palliative care patients with pruritus of different natures, treatment with the drug paroxetine, a selective serotonin reuptake inhibitor, may be beneficial. For patients suffering from pruritus associated with HIV infection, indomethacin was described as the most effective drug, although the evidence was weak. For patients suffering from chronic kidney disease-associated pruritus, gabapentin may be an option. An alternative treatment for this patient group seems to be the κ-opioid receptor agonist nalfurafine, which has shown significant amelioration of pruritus and acceptable adverse effects. As they have exhibited a low incidence of adverse effects, rifampicin and flumecinol may be recommended for patients with cholestatic pruritus. The opioid antagonist naltrexone has been shown to offer a therapeutic alternative for patients suffering from uraemic or cholestatic pruritus. However, these drugs are often inappropriate in the palliative population because of the risk of reducing analgesia when giving high doses of naltrexone.

AUTHORS' CONCLUSIONS

The findings of this review indicate that the number of systemic and topical drugs used for the different subforms of pruritus is increasing. Different interventions have been shown to be effective in the treatment of pruritus of different origins. Nevertheless, an optimal therapy for pruritus is constrained due to the limited understanding of crucial itch mediators and receptors in the various subforms of itch. Ideal antipruritic therapies are still lacking, especially for palliative care patients.This systematic review also indicates that there is insufficient evidence to give any concrete recommendations regarding treatment of pruritus in palliative care patients. Due to the very small sample sizes and poor methodological quality of the majority of studies that were included, the results of this review need to be interpreted with caution. Furthermore, the generalizability is questionable. Additional studies, and particularly carefully designed treatment trials, are needed to provide valid evidence for adequate treatment of pruritus in palliative care patients.

A prospective study of cutaneous abnormalities in patients with chronic kidney disease

There are diverse ways in which the skin is affected by chronic kidney disease (CKD). Various specific and nonspecific skin abnormalities are observed in patients with CKD. The aim of the study was to document the prevalence of skin diseases that commonly occur in patients with CKD on medical treatment and dialysis. A total of 99 patients with CKD were examined for evidence of skin diseases. Ninety-six had at least one cutaneous abnormality attributable to CKD. The most prevalent finding was xerosis (66.7%), followed by pallor (45.45%), pruritus (43.4%), and cutaneous pigmentation (32.3%). Other cutaneous manifestations included dermatitis (27.27%); Kyrle's disease (17.17%); fungal (8.08%), bacterial (11.1%), and viral (5.05%) infections; purpura (10.1%); gynecomastia (4.04%); and yellow skin (5.05%). The common nail changes were half and half nails (36.36%) and onycholysis (13.13%). CKD is associated with various cutaneous abnormalities caused either by the disease or by treatment, the most common being xerosis and pruritus. The dermatologic complications can significantly impair the quality of life in certain individuals; therefore, earlier diagnosis and treatment is important to improve their quality of life.

Efficacy of omega-3 fatty acids supplementation in treatment of uremic pruritus in hemodialysis patients: a double-blind randomized controlled trial

BACKGROUND

Uremic pruritus is a common and bothersome complaint among end-stage renal disease which affect between 25% and 60% of this population .But there is no decisive cure for treatment of it. In this study, the effects of omega-3 for treatment of pruritus were investigated in hemodialysis patients.

METHODS

A double-blind randomized study was carried out in the form of placebo-controlled crossover study in four dialysis centers in Tehran, Iran during 2008. At first, 22 hemodialysis patients suffering from pruritus with previous drug resistance were selected. Next, these patients were randomly allocated into two groups of omega-3-placebo (group A) and placebo-omega-3 (group B) .Patients in group A were treated with a 1-gram Fish oil capsule for 20 days, and subsequently, they were treated with placebo for 20 days after a 14-day wash-out period .But the reverse act was done in group B.The pruritus assessment was made quantitatively through Detailed Pruritus Score.

RESULTS

Pruritus was decreased up to 65% from score mean of 20.3 (95% CI: 16.7-23.8) to 6.4 (95% CI: 2.9-9.8) in omega-3 group and the decrease in the placebo group was 15% from score mean of 17.0 (95% CI: 12.4-21.6) to 14.4 (95% CI: 10.5-18.2).So the level of statistical difference was significant (P=0.0001).

DISCUSSION

Omega-3 fatty acids found to be more effective than placebo in decreasing of uremic pruritus. So it seems that Omega-3 fatty acids could be used as an efficient drug for treatment of pruritus in uremic patients.

Interleukin-2 serum levels are elevated in patients with uremic pruritus: a novel finding with practical implications

BACKGROUND

Uremic pruritus (UP) is still a common tormenting symptom among patients on hemodialysis (HD). The pathogenesis of UP is complex and not fully clarified. Some preliminary studies indicate that UP is a systemic inflammatory disease with a deranged balance of T helper (TH) cell differentiation toward TH1 predominance. The aim of this study was to further elucidate the potential contribution of TH1 cytokines to the pathogenesis of UP.

METHODS

In this study, 112 HD patients were screened for UP. After meeting the required criteria, 31 HD patients with UP were included in the study as case group and 30 age- and sex-matched HD patients without UP were enrolled as controls. The serum levels of interleukin (IL)-2 and interferon-γ (as TH1 cytokines), IL-4 (as a TH-2 cytokine), high-sensitive C-reactive protein (as an inflammatory marker), parathyroid hormone, calcium, phosphate, albumin and ferritin were measured in all patients. Moreover, blood variables including hemoglobin and mean corpuscular volume were also determined. The correlations of measured factors with UP severity were determined as well.

RESULTS

Except for the serum levels of IL-2, which were significantly higher in HD patients with itch versus those without it [0.544 ± 0.126 (U/mL) versus 0.318 ± 0.145 (U/mL); P < 0.0001], no statistically significant difference was observed in the levels of each of the above-mentioned factors between the two groups. Additionally, no correlation was detected between the levels of measured factors and UP severity.

CONCLUSIONS

The results of our study, for the first time, point to the potential important role of IL-2 in UP and further support the notion of TH1 overactivity in its pathogenesis. Our study paves the way for further studies focusing on the contribution of IL-2 to the UP, such as the experimental use of anti-IL-2 receptor antibodies.

The use of pregabalin in the treatment of uraemic pruritus in haemodialysis patients

We evaluated the effect of pregabalin in the treatment of uraemic pruritus not due to secondary hyperparathyroidism. Sixteen haemodialysis patients suffering from uraemic pruritus resistant to conventional treatment started on pregabalin 25 mg/day orally. The parameters recorded were age, time on haemodialysis, haematocrit, Ca, PO₄ , Ca × PO₄ product, PTH, spKt/V, eosinophil counts and IgE. The effectiveness of pregabalin on uraemic pruritus was evaluated by using visual analogue scale before and after one month of treatment. Visual analogue scale consisted of a 10-cm horizontal line scored from 0 (no itch) to 10 (worst imaginable itch). Four patients discontinued treatment due to side effects and therefore were excluded from the study. The mean age of the remaining 12 patients was 61.2 ± 12.8 years, and the time on haemodialysis was 38 ± 39.1 months. The haematological and biochemical profile of the patients remained without significant change at the end of the observation period. There was a statistically significant difference between visual analogue scale values before and after the one month treatment period (7.44 ± 2.01 and 1.7 ± 1.31, respectively), p < 0.0003. Uraemic pruritus is a common and distressing symptom in patients undergoing haemodialysis. Pregabalin appears to be an effective alternative treatment.

Effect of oral cromolyn sodium on CKD-associated pruritus and serum tryptase level: a double-blind placebo-controlled study

BACKGROUND

Generalized pruritus is a significant complication in end-stage renal disease patients. The mechanism is unknown and most treatments are ineffective. This study is the first clinical trial designed to evaluate the effect of cromolyn sodium (CS) on renal itch.

METHODS

Sixty-two haemodialysis (HD) patients with pruritus were enrolled into the study and were randomly assigned to receive CS or placebo (135 mg three times daily) for 8 weeks. Patients were asked to record the severity of their pruritus on each dialysis session on a visual analogue scale (VAS) during the 8 weeks of treatment and 4 weeks following discontinuation of treatment. Serum tryptase levels were determined at baseline, after 8 weeks of treatment and 4 weeks after discontinuation of treatment.

RESULTS

Data were analysed in 21 patients in the CS group and 19 patients in the placebo group that completed the study. A significant difference was seen in the severity of pruritus between the two groups during the period of study. Level of pruritus decreased from 8.48 +/- 2.2 to 0.9 +/- 1.8 after 8 weeks of treatment with CS. Geometric mean of serum tryptase at baseline and 8 weeks after treatment were 21.3 and 19.5 ng/ml for the CS group and 18.03 and 18.2 ng/ml for the placebo group, respectively. Although the geometric mean of tryptase had decreased in the CS group, this decrease was not statistically significant (P = 0.214).

CONCLUSION

CS can significantly reduce the severity of pruritus in HD patients, but this effect is not due to a decrease in serum tryptase level.

Gabapentin and uremic pruritus in hemodialysis patients

BACKGROUND

Pruritus is a common and bothersome problem in 30-50% of hemodialysis patients. The aim of this study was to determine the effect of gabapentin, 100 mg/three times a week (after each hemodialysis session), on uremic pruritus.

STUDY DESIGN

Patients older than 18 years who had undergone hemodialysis for more than three months were enrolled in this double-blind clinical trial. They had experienced pruritus refractory to antihistamines for at least two weeks. The patients were assigned to receive gabapentin 100 mg following hemodialysis for a period of four weeks, and after a washout week, they received the placebo for another four weeks. They were asked to evaluate the severity of their pruritus using a visual analogue scale (VAS). The reduction of pruritus >or= 50% was accepted as the response.

RESULTS

The mean pruritus score reached 6.44 +/- 8.4 (p < 0.0001), 15 +/- 11.2 (p < 0.001), and 81.11 +/- 11.07 (p < 0.001) during gabapentin, washout, and placebo periods, respectively. No significant correlation was found between age, sex, duration of dialysis, underlying diseases, and systolic and diastolic blood pressures and the gabapentin effect.

CONCLUSION

Gabapentin is an effective agent in treating uremic pruritus.

Skin problems in chronic kidney disease

Skin disorders associated with chronic kidney disease (CKD) can markedly affect a patient's quality of life and can negatively impact their mental and physical health. Uremic pruritus, which is frequently encountered in patients with CKD, is considered to be an inflammatory systemic disease rather than a local skin disorder. Biomarkers of inflammation are increased in patients with uremic pruritus and an imbalance of the endogenous opioidergic system might be involved in the complex pathogenesis of the disease. Treatment options for uremic pruritus include emollients, topical capsaicin cream, ultraviolet B phototherapy, gabapentin, oral activated charcoal and nalfurafine, a kappa-opioid-receptor agonist. Calcific uremic arteriolopathy is triggered by an imbalance of promoters and inhibitors of vascular calcification, caused by the inflammatory changes that occur in uremia. Promising therapeutic strategies for calcific uremic arteriolopathy include bisphosphonates and intravenous sodium thiosulfate. Nephrogenic systemic fibrosis is a devastating condition associated with the use of gadolinium-based contrast agents in patients with CKD. At present, no therapies are available for this complication. Preventive measures include use of iodine-based contrast agents, particularly in patients with CKD stage 4 and 5. If gadolinium contrast is necessary, administration of low volumes of the more stable macrocyclic ionic types of gadolinium-based contrast agent is advocated. Hemodialysis following gadolinium exposure might offer benefits but evidence is lacking.

An update on pruritus associated with CKD

The prevalence of chronic kidney disease (CKD) and end-stage renal disease is increasing worldwide. Despite improvements in dialysis methods, including the development of novel biocompatible membranes and ultrapure dialysate, CKD-associated pruritus remains a common and significant public health issue. Not only does this distressing symptom profoundly impact on quality of life and sleep, recent evidence showed that pruritus also was associated with poor patient outcome. Nonetheless, nephrologists and other health care professionals often fail to recognize and adequately address the pruritus associated with CKD. The pathophysiological mechanism of CKD-associated pruritus is poorly defined, and, as a result, the development of specific therapies has proved to be a challenge. The purpose of this review is to highlight the importance of this neglected topic by providing an overview of recent epidemiological studies, outcomes data, proposed pathophysiological mechanisms, and emerging treatment options.

Baseline serum levels of mast cell tryptase are raised in hemodialysis patients and associated with severity of pruritus

BACKGROUND

The pathogenesis of pruritus in renal disease is not yet understood. Evidence suggests that mast cells play a role; for example, the number of dermal mast cells is increased in patients on hemodialysis.

PATIENTS AND METHODS

To investigate a possible role of mast cell tryptase in pruritus of patients undergoing chronic hemodialysis, serum mast cell tryptase concentrations were measured in blood samples taken from 93 such patients, 53 of whom also recorded the severity of their pruritus on a visual analogue scale.

RESULTS

Serum mast cell tryptase levels were above 11.4 microg/l (95th percentile) in 84 of 93 hemodialysis patients (90.3 %). The intensity of pruritus correlated significantly (p = 0.014) with the tryptase levels, an associated not yet shown for other mast cell-related parameters.

CONCLUSIONS

Mast cells or even tryptase itself may be involved in the pathogenesis of pruritus of hemodialysis patients.