Chronic pruritus: evaluation of patient needs and treatment goals with a special regard to differences according to pruritus classification and sex

Clinical aspects and management of chronic itch

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

Predictive factors of quality of life in chronic pruritus patients: A cross-sectional study

Background

Chronic pruritus severely impacts the quality of life (QoL) of patients. Due to its multifactorial nature, the presence of factors that can predict itch-specific QoL needs comprehensive exploration.

Objective

To determine the sociodemographic and itch-related factors that predict itch-specific QoL among patients suffering from chronic pruritus.

Methods

We conducted a cross-sectional study on a cohort of patients with chronic pruritus at our itch clinic in Miami, Florida from 2016 to 2022 and explored predictors of itch-specific QoL using simple and multivariable linear regression models.

Results

Sociodemographic factors that had a negative impact on itch-specific QoL included female sex and multiracial ethnicity. The main itch-related factors that were associated with a negative impact on itch-specific QoL included pruritus in the upper extremity and buttocks/genital regions and associated factors such as pain, cold sensation, sweating, and stress.

Limitations

Single-center study at a tertiary care center with a primarily non-Hispanic White population and use of self-administered questionnaires.

Conclusions

A variety of factors help predict the itch-specific QoL in patients with chronic pruritus. Understanding these factors can help clinicians evaluate and treat patients suffering from chronic itch.

Cost-effectiveness and Quality of Specialized and Routine Care in a German Cohort of Patients with Chronic Pruritus

Chronic pruritus is a prevalent interdisciplinary symptom with a strong influence on health-related quality of life. Patients need extensive diagnostics and long-term treatment. This retrospective and prospective cohort study compared routine and university-based specialized care in terms of cost-effectiveness and patient benefit. Direct medical and non-medical costs and patient-reported outcomes (PRO; pruritus intensity, quality of life, treatment needs and benefits) were assessed. Data analyses were conducted using descriptive methods and non-parametric statistical tests. A total of 300 adult patients (54.3% female) participated in the study. Six months after the treatment start in a specialized German pruritus care unit, the total costs were significantly reduced (mean total costs 686 € vs 433 € per patient per half year (total cohort); p <  0.001; mean out-of-pocket costs 198 € vs 124 € per half year (total cohort), p <  0.001). Pruritus intensity (numerical rating  scale 5.3 vs 3.7, p < 0.001), quality of life (Dermatology Life Quality Index 8.9 vs 5.7, p < 0.001) and patient benefit (Patient Benefit Index Pruritus 1.2 vs 2.1, p < 0.001) improved significantly (total  cohort). The results of this study show, that treatment of chronic pruritus patients in a specialized itch centre leads to an improvement in patient  benefit and reduces the economic burden at the same time.

[Relevance of demographic and psychological factors in pruritus]

BACKGROUND

Pruritus is a frequent phenomenon in patients in dermatology. The severity of pruritus often cannot be explained by the severity of the underlying disease or chronification processes alone. Especially then, demographic and psychological variables should also be considered as moderators of the intensity of pruritus.

PURPOSE

Are there associations between sex, age, emotional and cognitive factors and pruritus intensity in patients with chronic pruritus (CP) and skin-healthy control subjects?

MATERIAL AND METHODS

Recently published studies on the abovenamed moderators of pruritus were searched for in PubMed, collated and the results are summarized.

RESULTS

It was found that women reported a higher intensity of pruritus than men. In addition, negative emotions such as fear, disgust, and anger are positively associated with pruritus in patients with CP. There are also associations between cognitive factors, such as attention, catastrophizing, and pruritus.

CONCLUSION

The associations between both demographic and psychological factors and pruritus should be considered in the diagnostics and treatment of pruritus. A psychological intervention as a complementary treatment should be considered whenever patients report associations between psychological experiences and pruritus and/or automatic or extensive scratching.

Skin Lesions, Skin Care, and Characteristics of Pruritus in Patients Undergoing Haemodialysis

INTRODUCTION

Pruritus has been shown to be a common and burdensome complaint in the general population. In some diseases, there is an even higher rate and intensity of pruritus such as in chronic kidney diseases. In particular, patients requiring dialysis commonly suffer from pruritus with proportions between 22.0 and 90.0%. Few data on the characteristics and burden of such pruritus have been published. Therefore, the aim of this study was to investigate the extent and profiles of pruritus in such patients related to skin lesions and care.

METHODS

A non-interventional cross-sectional study in 14 centres for haemodialysis across Germany was conducted. The survey explored the prevalence, severity, and resulting burden of pruritus and skin lesions.

RESULTS

In total, 302 patients with uraemia (56.5% male, mean age 66.0 ± 14.4 years, mean duration of dialysis 3.9 ± 4.8 years) were included. Skin lesions appeared since start of dialysis in 50.0% of patients, with xerosis (94.7%) and desquamation (25.8%) being the most frequent and disturbing findings. Pruritus was reported by 60.9% of patients undergoing dialysis with a current mean numerical rating scale of 5.1 ± 2.4 occurring most frequently in the back, legs, and arms. About 89.0% of patients with xerosis and 69.0% with desquamation reported self-medication. However, only 40.0% and 28.0% sought medical help, respectively, indicating a remarkable lack of healthcare.

DISCUSSION

The current data suggest a more intensive focus on the skin symptoms and signs related to uraemia in the patients with dialysis and thus underline claims from a previous German large-scale study. Recommendations for early treatment and prevention of skin lesions in dialysis patients should be developed. Further research should be conducted focusing on recognizing subgroups of patients of particular vulnerability to pruritus and skin lesions, which may facilitate identifying patients at risk in an early moment. Moreover, a more specific tool for screening of skin lesions as well as pruritus may be useful since the existing instruments lack such specificity.

When life is an itch: What harms, helps, and heals from the patients' perspective? Differences and similarities among skin diseases

Itch is the commonest skin-related symptom, associated with a high psychosocial and economic burden. While the main focus of itch research lies on a few chronic skin diseases, only little is known about the perception of itch, itch-aggravating/-relieving factors and treatment preferences in patients with acute and chronic itch of various etiology. In this cross-sectional study, we assessed these aspects in 126 patients (mean age 61.7 ± 18.4 years, 67 females, median itch duration 3.9 years) using a 78-item questionnaire. The diseases were categorized into 11 diagnostic groups for descriptive analysis; the three most frequent groups ("atopic dermatitis," "nonatopic eczema," "inflammatory dermatoses") were statistically compared. Itch was most often perceived as localized 42.9%, burning (40.5%), and worrying (39.7%) with worsening in the evening (49.2%), due to warmth (42.1%) and sweating (26.2%). While itch perception, itch-aggravating factors and treatment preferences differed broadly among patients, the itch-relieving personal strategies were more uniform ("scratching by hand 70.6%, applying topicals 57.9%). Also, 69.8% of patients suffered from itch-related sleep disturbance, consequently affecting their relatives in 30.0%. Subgroup comparisons revealed significant differences regarding itch-aggravating factors (P = .0012) and itch duration (P = .0082). Patients rated the antipruritic effectiveness of phototherapy, "complementary and alternative medicine" and "other tablets" as high, but oral antihistamines, "cortisone tablets" and any topical as only moderately efficacious. The preferred administration of an ideal itch treatment was "creams/ointments" (51.6%) or "tablets" (35.7%), only few patients preferred "injections" or "patches." Consideration of such differences and similarities in itch characteristics and treatment preferences could help to better tailor treatment in itch patients.

Influence of Climate on Google Internet Searches for Pruritus Across 16 German Cities: Retrospective Analysis

BACKGROUND

The burden of pruritus is high, especially among patients with dermatologic diseases. Identifying trends in pruritus burden and people's medical needs is challenging, since not all affected people consult a physician.

OBJECTIVE

The purpose of this study was to investigate pruritus search behavior trends in Germany and identify associations with weather factors.

METHODS

Google AdWords Keyword Planner was used to quantify pruritus-related search queries in 16 German cities from August 2014 to July 2018. All identified keywords were qualitatively categorized and pruritus-related terms were descriptively analyzed. The number of search queries per 100,000 inhabitants of each city was compared to environmental factors such as temperature, humidity, particulate matter 10 micrometers or less in diameter (PM10), and sunshine duration to investigate potential correlations.

RESULTS

We included 1150 pruritus-related keywords, which resulted in 2,851,290 queries. "Pruritus" (n=115,680) and "anal pruritus" (n=102,390) were the most-searched-for keywords. Nearly half of all queries were related to the category localization, with Berlin and Munich having a comparatively high proportion of people that searched for pruritus in the genital and anal areas. People searched more frequently for information on chronic compared to acute pruritus. The most populated cities had the lowest number of queries per 100,000 inhabitants (Berlin, n=13,641; Hamburg, n=18,303; and Munich, n=21,363), while smaller cities (Kiel, n=35,027; and Freiburg, n=39,501) had the highest. Temperature had a greater effect on search query number (beta -7.94, 95% CI -10.74 to -5.15) than did PM10 (beta -5.13, 95% CI -7.04 to -3.22), humidity (beta 4.73, 95% CI 2.70 to 6.75), or sunshine duration (beta 0.66, 95% CI 0.36 to 0.97). The highest relative number of search queries occurred during the winter (ie, December to February).

CONCLUSIONS

By taking into account the study results, Google data analysis helps to examine people's search frequency, behavior, and interest across cities and regions. The results indicated a general increase in search queries during the winter as well as differences across cities located in the same region; for example, there was a decline in search volume in Saarbrucken, while there were increases in Cologne, Frankfurt, and Dortmund. In addition, the detected correlation between search volume and weather data seems to be valuable in predicting an increase in pruritus burden, since a significant association with rising humidity and sunshine duration, as well as declining temperature and PM10, was found. Accordingly, this is an unconventional and inexpensive method to identify search behavior trends and respective inhabitants' needs.

Sex differences in the pharmacology of itch therapies-a narrative review

BACKGROUND

Chronic itch is the most common skin-related condition, associated with a high psychosocial and economic burden. In recent years, increasing evidence of sex differences in the perception, clinical presentation and treatment requirements of itch points towards potential benefits when using sex-adapted therapies. It is well-known that body composition, absorption, metabolism, elimination and adverse drug reactions (ADRs) differ between sexes, but only little is known about the impact of sex in the pharmacology of itch treatments, which could help to rationalise sex-adapted treatment strategies.

AIM

To evaluate and review sex effects in the pharmacokinetics and /-dynamics of drugs used to treat itch.

METHODS

In this narrative review we performed a PubMed and MEDLINE (Ovid) search using the terms (itch OR pruritus) AND (gender OR sex) AND (drug OR medication OR pharmacokinetics OR pharmacodynamics). Additional searches were performed for the topical and systemic drugs recommended by the European Guideline on Chronic Pruritus.

RESULTS

We found numerous reports with variable levels of evidence of sex effects with respect to the pharmacokinetics and/or pharmacodynamics of 14 drug classes used for the treatment of itch, including a total of 19 systemic and 3 topical drugs. Women seem to present higher plasma levels of several drugs used in itch treatment, including tri- and tetracyclic antidepressants (e.g. doxepin, amitriptyline, mirtazapine), serotonin reuptake inhibitors (e.g. paroxetine, sertraline, fluoxetine), immunosuppressive drugs (e.g. cyclosporine, mycophenolate mofetil), serotonin receptor antagonists (e.g. ondansetron) and betablockers (e.g. propranolol). Adverse drug reactions (ADRs) were generally more common in women. Being female was reported to be an independent risk factor for QTc-prolongation associated with antihistamines and tetracyclic antidepressants. Additionally, women seem to be more prone to sedative effects of antihistamines, and to suffer from a higher frequency as well as severity of side effects with systemic calcineurin inhibitors, opioid agonists, and opioid antagonists. Women were also sensitised more often to topically applied drugs. Of note, apart from only one experimental study with capsaicin, none of these reports were designed specifically to assess the effect of sex (and gender) in the treatment of itch.

DISCUSSION/CONCLUSION

Our review supports previous reports that sex is of importance in the pharmacokinetics and /-dynamics of several drugs used to treat itch although those drugs were mostly evaluated for non-itch indications. However, the results are limited by methodological limitations evident in most studies such as underrepresentation of women in clinical trials. This emphasises the need to study the impact of sex (and gender) in future itch trials to yield better outcomes and prevent ADRs in both sexes.

Humanistic burden of chronic pruritus in patients with inflammatory dermatoses: Results of the European Academy of Dermatology and Venereology Network on Assessment of Severity and Burden of Pruritus (PruNet) cross-sectional trial

BACKGROUND

Chronic pruritus is a multifactorial, challenging symptom of global relevance.

OBJECTIVE

The European Academy of Dermatology and Venereology Network on Assessment of Severity and Burden of Pruritus (PruNet) investigation aimed to analyze the severity and humanistic burden of chronic pruritus in patients suffering from inflammatory dermatoses across Europe.

METHODS

Prospectively collected routine data on 552 patients (with atopic dermatitis, contact dermatitis, prurigo nodularis, psoriasis vulgaris, lichen planus, or mycosis fungoides [pruritus numeric rating scale score ≥3]) from 9 European centers (in Austria, France, Germany, Italy, Poland, Russia, Spain, Switzerland, and Turkey) were analyzed by univariate and multivariate variance analyses of various itch characteristics and quality of life (as measured by the Dermatology Life Quality Index and the ItchyQoL).

RESULTS

Duration, frequency, and intensity of pruritus (according to a numeric rating scale and visual analog scale) and related impairment of quality of life differed between European centers and dermatologic diagnoses (P < .05). The country in which the center was located had a greater impact on how patients evaluated pruritus intensity and quality of life than diagnosis did (P < .001).

LIMITATIONS

One center per country was included.

CONCLUSION

The humanistic burden of chronic pruritus in patients with inflammatory dermatoses is high. European cross-cultural factors may have a stronger influence than a specific dermatologic diagnosis on how patients rate intensity of pruritus and quality of life.

[Treatment of chronic pruritus-what is new?]

Chronic pruritus is one of the most common and stressful symptoms in medicine. Therapy remains a great challenge because of the lack of approved therapies. In the recent past a greater understanding of the pathogenesis has enabled the results to be translated into new forms of therapy. The various therapies target a wide range of points in the pruritic cascade-from blockade of intracellular and intercellular signaling pathways in the skin to the modulation of neurotransmission. This article provides a summary of current therapeutic options based on the current S2K guideline and gives an overview about recent developments in antipruritic treatments.

Management of chronic pruritus: from the dermatological office to the specialized itch center: a review

Patient care for those affected by chronic pruritus is remarkably complex due to its high prevalence and multifactorial nature. It requires a comprehensive assessment of the patient’s medical history, extensive diagnostic procedures, and long treatment duration, including management of possible accompanying disorders such as sleep disturbances and mental distress. It is important to prioritize patient’s needs when developing a therapeutic treatment plan. Standardized questionnaires and scales should be used to better analyze the patient history, quality of life, symptom intensity, and course of treatment. These can be distributed via digital platforms, allowing for more effective communication between the treating agents and gathering of large volumes of data in central databases. In today’s health care system, it is essential for physicians with itch-related specializations and specialized itch centers to cooperate. It is thus crucial to focus efforts on the further development of specialized treatment centers and training courses for medical practitioners. There are, however, various regulatory and economic barriers to overcome in the modern health care system before patients with chronic pruritus can be offered the best possible care. Accordingly, health care authorities should be made aware of the difficulties associated with the management of chronic pruritus and of the high individual and societal burden it represents.

Ex vivo skin permeation and penetration of nonivamide from and in vivo skin tolerability of film-forming formulations containing porous silica

AIM

The purpose of this study was to evaluate skin permeation and penetration of nonivamide which has been formulated in novel film-forming formulations (FFFs). These formulations aim to prolong the availability of capsaicinoids which are used in long-term treatment of chronic pruritus.

METHODS

An oily solution of nonivamide was loaded into porous silica particles which then were suspended in an aqueous dispersion of a sustained release polymer. Permeation and penetration experiments were performed ex vivo with postauricular porcine skin using modified Franz diffusion cells. The penetrated drug amount was assessed ex vivo by skin surface biopsy followed by cryo-sectioning. Furthermore, in vivo skin irritation experiments were performed to compare the potential skin irritation caused by the FFFs to conventionally used semi-solid formulations.

RESULTS

Permeation rates of nonivamide from FFF through the skin are comparable to that from clinically used immediate release formulations. This elucidates the therapeutic safety profile of the novel FFF. Penetration studies confirmed the prolonged drug availability at the site of action. FFFs were found not to irritate the skin of healthy volunteers.

CONCLUSION

FFFs with sustained nonivamide penetration represent safe and easy-to-use formulations. They therefore may improve the treatment of chronic pruritus with capsaicinoids by enhancing patient compliance through a sustained release regime.