Pruritus as a leading symptom: clinical characteristics and quality of life in German and Ugandan patients

Xanthotoxol relieves itch in mice via suppressing spinal GRP/GRPR signaling

Although pruritus, commonly known as itch, is a common and debilitating symptom associated with various skin conditions, there is a lack of effective therapies available. Xanthotoxol (XAN), a biologically active linear furocoumarin, shows potential in the treatment of various neurological disorders. In this study, we discovered that administering XAN either through intraperitoneal or intrathecal injections effectively reduced scratching behavior induced by compound 48/80 or chloroquine. Importantly, XAN also substantially alleviates chronic itch in dry skin and allergic contact dermatitis mice. Substantial progress has highlighted the crucial role of gastrin-releasing peptide (GRP)-gastrin-releasing peptide receptor (GRPR) signaling in the dorsal spinal cord in transmitting various types of itch. Our behavior tests revealed that XAN significantly alleviated scratching behaviors induced by intrathecal administration of GRP or GRPR agonist bombesin. Furthermore, XAN reduced the activation of neurons in the spinal cord caused by intrathecal administration of GRP in mice. Moreover, XAN attenuates the activation of spinal GRPR-positive neurons in itchy mice. These findings suggest that XAN mitigates itch in mice by suppressing spinal GRP/GRPR signaling, thereby establishing XAN as a promising therapeutic option for treating pruritus.

Prevalence and Characteristics of Itch and Pain in Patients Suffering from Chronic Hand Eczema

BACKGROUND

Hand eczema (HE) is a frequent chronic inflammatory dermatosis. Itch and pain are considered two of the most common and burdensome symptoms of the disease. Yet, the data related to these symptoms are still limited. The aim of this study was to evaluate characteristics of itch and pain in adults suffering from HE.

METHODS

The study group comprised 100 adult HE patients. An original questionnaire designed by the authors was used to survey the patients. It included questions regarding demographic characteristics such as the duration of the disease, exacerbation count, past diagnostics and treatment, as well as atopic predispositions. Additionally, the itch and pain intensity (numerical rating scale-NRS) during '3 days prior to the study' and the 'entire disease' period was implemented. The clinical assessment of the disease severity was performed according to two specific measurement instruments: Investigator Global Assessment for Chronic Hand Eczema (IGA-CHE) scale and Hand Eczema Severity Index (HECSI). To assess patient quality of life (QoL), the DLQI tool was used and to determine the level of stigmatization and for its impact on patients' life the 6-Item Stigmatization Scale (6-ISS) was employed.

RESULTS

Within the period of 3 days prior to the examination, itch was reported by 81.0% of patients (n = 81), whereas 53.0% (n = 53) of them experienced pain. Both symptoms were reported more frequently in females (itch: p = 0.022; pain: p = 0.033). When sexes were compared, females reached higher scores in both IGA-CHE and HECSI. Itch and pain intensity correlated positively with disease severity. The intensity of itch and pain significantly influences HE patients' QoL. A positive correlation between the 6-ISS score and the intensity of itch in the 'last 3 days' period was revealed (r = 0.221; p = 0.027).

CONCLUSIONS

Itch and pain are common symptoms in HE patients, significantly contributing to the feeling of stigmatization. Providing characteristics of itch and pain may improve HE management. Symptom-decreasing treatment would definitely have a positive influence on patients' well-being.

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

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

Apigenin: A Therapeutic Agent for Treatment of Skin Inflammatory Diseases and Cancer

The skin is the main barrier between the body and the environment, protecting it from external oxidative stress induced by ultraviolet rays. It also prevents the entrance of infectious agents such as viruses, external antigens, allergens, and bacteria into our bodies. An overreaction to these agents causes severe skin diseases, including atopic dermatitis, pruritus, psoriasis, skin cancer, and vitiligo. Members of the flavonoid family include apigenin, quercetin, luteolin, and kaempferol. Of these, apigenin has been used as a dietary supplement due to its various biological activities and has been shown to reduce skin inflammation by downregulating various inflammatory markers and molecular targets. In this review, we deal with current knowledge about inflammatory reactions in the skin and the molecular mechanisms by which apigenin reduces skin inflammation.

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

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

Mapping research evidence on quality of life in children with atopic dermatitis in sub-Saharan Africa: a scoping review protocol

BACKGROUND

Atopic dermatitis (AD) is a chronic, debilitating disease affecting children worldwide. Several studies have shown the disease to be a significant problem which leads to a diminished quality of life (QoL) for the affected children, but systematic evaluation of such studies in Africa is yet to be reported. Therefore, this scoping review aims to map research evidence on children with AD and their QoL in sub-Saharan Africa (SSA).

METHODS

The scoping review will follow the Arksey and O'Mally methodological framework. The electronic databases to be searched will include PubMed, EBSCOhost (Academic Search Complete, CINAHL, PsycINFO, and Health Sources), and Scopus and Google Scholar, for published literature between 2010 and 2021. The search strategy for the databases will include keywords, Medical Subject Headings terms, and Boolean operators. The reference list of the included sources of evidence and the WHO website will also be consulted for evidence relating to QoL of children with AD in SSA. Two independent reviewers will undertake abstract and full-text article screening with the guidance of eligibility criteria. This review will include studies conducted in SSA, and publications focusing on QoL and associated factors of AD in children. Data will be extracted from the included studies and analyzed qualitatively; NVIVO software V.11 will be used, and the emerging themes reported narratively. The mixed-method appraisal tool (MMAT) will be employed for quality appraisal of included studies.

DISCUSSION

We look forward to the findings of several studies that describe the QoL and associated factors among children with AD and that report on the use of different diagnostic criteria, severity scaling and QoL measuring scale tools used to ascertain the presence of AD, scale the severity of AD, and the impact of AD on QoL among children. This will help to improve clinical practice and the QoL of children with AD in SSA. The study findings will be disseminated through publication in a peer-reviewed journal, peer presentations, and presentations at relevant conferences.

CONCLUSION

This study will add new knowledge on the QoL in children with AD in the SSA context. The study has the potential to inform research and clinical practice to impact the QoL of children with AD in SSA.

Relationships of pain-causing substances with dry skin and effects of zaltoprofen on alleviation of symptoms in arthritis model mice

Skin dryness is a symptom of rheumatoid arthritis (RA). However, the mechanisms through which dry skin is induced in RA are unclear. Accordingly, in this study, we characterized substances related to pruritus and pain and then evaluated whether oral administration of zaltoprofen (ZLT) alleviated the symptom of dry skin induced by RA in model mice. DBA/1JJmsSlc collagen-induced arthritis model mice were treated with ZLT, and transepidermal water loss (TEWL), capacitance, and inflammation-, pruritus-, and pain-related markers were assessed. Our findings demonstrated that arthritis model mice treated with ZLT exhibited suppression of increases in TEWL and decreases in capacitance. Furthermore, ZLT also blocked the increase in mast cell numbers, substance P expression, and cyclo-oxygenase-2 expression in the skin and prevented enhancement of plasma levels of thymic stromal lymphopoietin, tumor necrosis factor-α, interleukin-6, histamine, and bradykinin. No changes in plasma levels of corticosterone or reactive oxygen species or skin levels of glucocorticoid receptor were observed in ZLT-treated arthritis model mice. Overall, these findings suggested that patients with RA may benefit from biopharmacy to alleviate joint symptoms and nonsteroidal anti-inflammatory drugs for pain relief and alleviation of skin symptoms.

Psychosocial Burden of Itch among Renal Transplant Recipients

Itch is the most common symptom of chronic dermatoses. Moreover, itch may be associated with systemic disorders. Chronic kidney disease—associated itch (CKD-aI) may affect up to 20% of renal transplant recipients (RTR). The aim of the study was to assess psychosocial burden of itch in RTR. The study was performed on a group of 129 RTR, out of which 54 (41.9%) experienced itch in the previous 3 days. A specially designed questionnaire assessing anxiety, depression, stigmatization, and quality of life was used. Results: Patients suffering from itch in the previous 3 days achieved significantly higher scores in GAD-7 (p < 0.001), BDI (p < 0.001), HADS total score (p < 0.001), HADS Depression (p = 0.004), and HADS Anxiety (p < 0.001). Severity of itch correlated positively with HADS, stigmatization scale, and GAD-7. Itch in RTR was associated with higher incidence of depression assessed with BDI (OR 3.7). Moreover, higher prevalence of anxiety was found among patients suffering from CKD-aI, assessed with HADS A and GAD-7 (OR 2.7 and OR 4.8, respectively) The results of our study clearly demonstrate that itch among RTR is a significant burden. Higher prevalence of depression and anxiety in this groups indicate the necessity of addressing itch relief as a part of holistic approach to patients after renal transplantation.

Acupuncture for the Treatment of Itch: Peripheral and Central Mechanisms

Despite the widespread clinical use of acupuncture in the treatment of pruritus caused by psoriasis, urticaria, uremic, and other diseases, insights into the mechanism of action of acupuncture are still emerging. For the above reasons, a beneficial effect of acupuncture on pruritus was not recommended or reported in recent clinical practice guidelines. Acupuncture is a kind of physical stimulation, which has the characteristics of multi-channel and multi-target effects. The biomechanical stimulation signal of acupuncture needling can be transformed into bioelectric and chemical signals; interfere with kinds of cells and nerve fibers in the skin and muscle; alter signaling pathways and transcriptional activity of cells, mediators, and receptors; and result in inhibition of peripheral and central transmission of pruritus. Available mechanistic data give insights into the biological regulation potency of acupuncture for pruritus and provide a basis for more in-depth and comprehensive mechanism research.

Phototherapy for Generalized Pruritus of Unknown Origin: Single-Center Experience

OBJECTIVE

Phototherapy is a well-established therapy in dermatology. However, there is limited evidence regarding phototherapy for the treatment of generalized pruritus of unknown origin (GPUO). The objective of this study was to assess the efficacy and safety of narrowband ultraviolet B (NB-UVB) phototherapy in patients with GPUO.

METHODS

Researchers conducted a retrospective review of the treatment outcomes of patients with GPUO who were treated with NB-UVB between 2004 and 2019 at their facility.

RESULTS

Investigators included 67 patients diagnosed with GPUO treated with NB-UVB. Complete remission was achieved in more than 70% of the patients. No serious adverse events were documented.

CONCLUSIONS

For patients with GPUO, NB-UVB may be a safe and effective treatment option.

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

Background

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

Aim

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

Design

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

Setting and Patients

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

Results

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

Conclusion and Patient Contribution

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

Approach to the Patient with Chronic Pruritus

Chronic pruritus (itch lasting ≥6 weeks) is a bothersome chief complaint that may present in a broad variety of diseases. Most itch-causing diagnoses fit into 1 of 5 categories (inflammatory, secondary to systemic disease, neuropathic, chronic pruritus of undetermined origin, and psychogenic itch) and this broad differential can be narrowed using key findings in the history and physical. In this article, we discuss which key findings are most pertinent for narrowing this differential and guiding further workup and treatment, as well as how to treat many itchy conditions.

Development and preliminary validation of the patient-reported Chronic Itch Burden Scale assessing health-related quality of life in chronic pruritus

BACKGROUND

Chronic pruritus (CP) significantly affects patients' health-related quality of life (HRQoL). Very few self-reported HRQoL questionnaires exploring CP have been developed according to international guidelines, thus limiting their use in preauthorization trials.

OBJECTIVES

To develop a self-reported HRQoL questionnaire in patients with CP owing to psoriasis, atopic dermatitis, seborrhoeic dermatitis of the scalp or idiopathic dermatitis, and to explore the preliminary psychometric properties of the questionnaire.

METHODS

The study was performed in France. A conceptual framework was developed based on a structured literature review and expert insight, and was improved using three focus groups involving 19 participants. A 50-item questionnaire was created and tested with 21 participants using cognitive debriefings; 11 items were removed. A cross-sectional study including 251 participants was performed to explore the preliminary psychometric properties of the 39-item questionnaire. Dimensionality was explored using principal component analysis. Cronbach's alpha and correlation coefficients (interitem, item-total score and item-dimension score) were measured. The number of items was reduced through expert consensus.

RESULTS

In the 39-item version, three main dimensions were identified (Cronbach's alpha = 0·94) and all correlation coefficients were > 0·34. Upon review, 13 items were deleted owing to poor quality and six items were deleted by the team, generating a 20-item version. The questionnaire's factorial structure was best reflected with a two-dimension solution, i.e. (i) social and emotional repercussions and (ii) relation to others, fear of judgement.

CONCLUSIONS

The Chronic Itch Burden Scale patient-reported questionnaire explores broad aspects of HRQoL that are relevant for patients with various skin diseases. Its good cross-sectional validity makes it useful for trials and practitioners.

Longitudinal association between polypharmacy and development of pruritus: a Nationwide Cohort Study in a Japanese Population

BACKGROUND

Although polypharmacy is known to cause side-effects due to drug-drug interactions, dermatological symptoms triggered by polypharmacy are not fully addressed.

OBJECTIVE

To investigate whether polypharmacy is associated with the risk of pruritus.

METHOD

A cohort study was performed to examine cross-sectional and longitudinal relationships between polypharmacy and pruritus in a general population. Data were collected from the Norm Study conducted in 2016 and 2017, which is a nationwide survey based on a self-administered questionnaire with Japanese representative participants aged 16-84 years. Presence of polypharmacy which was defined as concurrent use of ≥5 prescribed drugs. Primary outcomes were the presence of severe pruritus at baseline for the cross-sectional analysis and the development of severe pruritus after one year for the longitudinal analysis. Multivariable modified Poisson regression analyses were performed to estimate risk ratios (RRs) and 95% confidence intervals (95%CIs) with adjustment for potential confounders (age, gender, smoking habits, drinking habits, depressive symptoms, moderate activities based on IPAQ score and presence of 11 comorbid conditions including skin disease).

RESULTS

The study included 3126 participants (mean age, 48.7 years); nearly half (49.8%) were male. In all, 332 participants (10.3%) had polypharmacy in the cross-sectional analysis. Participants with polypharmacy were more likely to present with severe pruritus at baseline than those who were not using drugs (adjusted RR = 1.52 [95%CI 1.15-2.01, P = 0.003]). The longitudinal analysis (n = 1803) was limited to those without severe pruritus at baseline; participants with polypharmacy at baseline were more likely to develop severe pruritus after a one-year follow-up period than those not using drugs (adjusted RR = 1.46 [95%CI 1.14-1.87, P = 0.002]).

CONCLUSION

Polypharmacy was associated with the presence of pruritus at baseline and may predict the future risk of developing pruritus.

Clinical characteristics of itch in cutaneous lupus erythematosus: A prospective, multicenter, multinational, cross-sectional study

OBJECTIVE

Pruritus is an important symptom frequently accompanying various inflammatory skin conditions and some recent data indicated that it may be associated with autoimmune connective tissue diseases. The aim of this study was to assess the frequency and clinical presentation of itch in CLE.

METHODS

A multinational, prospective, cross-sectional study was performed to assess the prevalence, intensity and clinical characteristic of pruritus in various subtypes of CLE. A total of 153 patients with active CLE lesions were included. Their age ranged between 17 and 82 years (mean 49.8 ± 15.4 years), and 115 patients (75.2%) were women. The disease activity and damage were assessed according to the Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI). Pruritus severity was assessed with Numeric Rating Scale (NRS) and the 12-Item Pruritus Severity Scale. Dermatology Life Quality Index and EQ-5D questionnaire were used to measure quality of life.

RESULTS

Pruritus was present in 116 (76.8%) of patients of whom half had NRS scoring equal or above 4 points indicating moderate or severe pruritus. Most commonly itch was localized on the scalp, face (excluding ears and nose) and arms (40.5%, 36.2%, 31.9%, respectively). Sensations connected with pruritus were most frequently described as burning, tingling and like ants crawling feeling, but 31.9% patients described it as "pure itch". More than half of patients reported that pruritus was present every day, and it was most frequent during the evenings. The pruritus scoring and the CLASI activity score were significantly correlated (r = 0.42, p = 0.0001), while no correlation was found with the CLASI damage score (p = 0.16). Both the maximum and average itch intensity were correlated with systemic lupus erythematosus (SLE) activity measured with the Systemic Lupus Erythematosus Disease Activity Index.

CONCLUSIONS

Pruritus is a common, but frequently overlooked symptom of CLE. Its intensity correlates with the activity of CLE, but not with the skin damage. In more than a half of patients it occurs on a daily basis. The correlation between the intensity of pruritus and the activity of the skin lesions and the systemic involvement indicate that pruritus could be an individual indicator of both SLE and CLE activity.

Refinement and validation of the ItchyQoL using classical test theory and item response theory resulted in a reduction of the response categories from a 5-point to a 3-point scale

BACKGROUND

The ItchyQoL is an itch-specific patient-reported outcome measure used to assess quality of life in patients with chronic pruritus (CP).

OBJECTIVES

We aimed to assess and extend the psychometric properties of the ItchyQoL using classical test theory (CTT) and item response theory (IRT).

METHODS

Item characteristic curves were analysed to investigate whether the response categories were functioning optimally. Confirmatory factor analyses were carried out on the ItchyQoL prior to and after rescoring of the response categories. We conducted a Rasch analysis for the ItchyQoL with revised response options and assessed the mean fit residuals in addition to the assumptions of unidimensionality and local independence.

RESULTS

In total, 551 patients with CP from nine European countries completed the 22 items of the ItchyQoL. IRT analysis supported the revision of response options from five points to three. This revision was supported by excellent structural validity using CTT. The overall fit to the Rasch model was adequate. Unidimensionality was supported by the ItchyQoL overall scale and by the single subscales; however, local independence was violated in eight cases.

CONCLUSIONS

We suggest a revision of the response categories of the ItchyQoL from a 5-point to a 3-point scale. When this revision was applied, the ItchyQoL showed excellent structural validity according to CTT and IRT/Rasch. The calculation of an overall ItchyQoL sum score is allowed.

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

Background

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

Objective

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

Methods

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

Results

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

Limitations

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

Conclusion

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

Methyl Paraben May Increase Risk of Pruritus in African Americans Whereas Triclosan Is Inversely Associated With Pruritus and Eczema

BACKGROUND

Phenols and parabens (P&Ps) are commonly found in skin care products. However, P&Ps' role in pruritus and eczema has not been studied.

OBJECTIVE

The aim of the study was to investigate the association between P&Ps, and pruritus and eczema.

METHODS

This is a cross-sectional population-based study of 2202 participants. We examined the association between urinary phenols (triclosan, bisphenol A, benzophenone-3) and parabens (methyl and propyl parabens) and itchy rash/eczema using the 2005-2006 National Health and Nutrition Examination Survey database. Phenols and parabens were divided into quartiles (Qs) with the first Q as the reference. We calculated odds ratios and 95% confidence intervals, adjusting for multiple variables.

RESULTS

Urinary triclosan was inversely associated with itchy rash (P trend = 0.048). In a subpopulation analysis by race/ethnicity, urinary methyl paraben was positively associated with itchy rash in African Americans (fourth Q vs first Q: odds ratio, 12.60; 95% confidence interval, 1.03-154.06; P trend = 0.02). Triclosan was inversely associated with eczema in whites (P trend = 0.04).

CONCLUSIONS

Methyl paraben exposure may increase the risk of itchy rash in African Americans, whereas triclosan may decrease the risk of itchy rash and eczema. The potential effect of triclosan and methyl paraben in pruritus and eczema warrants further study.

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

BACKGROUND

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

OBJECTIVES

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

METHODS

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

RESULTS

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

DISCUSSION

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

Psychosocial stress of dermatology inpatients and their relatives - Comparison of patients with and without cancer

BACKGROUND

In the clinical treatment pathways of certified oncological centers, psychotherapeutic services are mandatory. Although patients with somatic, non-oncological illnesses show an equally high prevalence of psychosocial stress, these guidelines do not exist for the general hospital sector. Are these patients really less burdened and is psychological support only needed in individual cases? The example of dermatological patients will be used to show whether the need for psychosocial care and the desire for support vary between individuals with and without malignant disease.

PATIENTS AND METHODS

Using the Hornheider screening instrument and distress thermometer, 216 dermatological inpatients assessed their psychosocial stress and that of a close relative. In addition, they were asked about their desire for support and preferred support provider.

RESULTS

i) Patients without skin cancer were more frequently and more severely distressed than cancer patients. ii) Patients of both groups assessed their relatives to be approximately equally distressed. Compared with their own distress, cancer patients assessed their relatives as more frequently and on average more severely distressed. More than 50 % of all patients regarded their own disease as the cause of their relatives' distress. iii) The desire for support in both groups was about 18 %. iv) Doctors and psychologists were usually named as potential contact persons.

CONCLUSIONS

The expansion of psychosocial support services for non-tumor patients and their relatives seems necessary. The establishment of appropriate screening methods should be considered. Further studies in other clinical areas are required.

Burden and socioeconomics of asthma, allergic rhinitis, atopic dermatitis and food allergy

INTRODUCTION

Asthma, allergic rhinitis, atopic dermatitis, and food allergy affect approximately 20% of the global population. Few studies describe the burden of the totality of these diseases and only a handful studies provide a comprehensive overview of the socioeconomic impact of these diseases.

AREAS COVERED

For this narrative review, we searched Pubmed using selected keywords and inspected relevant references using a snowballing process. We provide an overview of the socioeconomic burden of allergic diseases (in particular, asthma, allergic rhinitis, atopic dermatitis, and food allergy). The focus of this review is on their epidemiology (incidence, prevalence), burden (disability-adjusted life years, quality of life), and direct and indirect costs (absenteeism and presenteeism). We have put special emphasis on differences between countries.

EXPERT COMMENTARY

Both the prevalence and the burden of allergic diseases are considerable with prevalence varying between 1% and 20%. We identified a plethora of studies on asthma, but studies were generally difficult to compare due to the heterogeneity in measures used. There were only few studies on the burden of food allergy; therefore, more studies on this allergy are required. For future studies, we recommend standardizing epidemiologic, socioeconomic impact, and quality of life measures of allergic diseases.

Effects of Stress on Itch

PURPOSE

Psychological stress and ensuing modulation of the immune and nervous systems can have a significant impact on itch. Stress can exacerbate itch and vice versa, resulting in a vicious cycle that can greatly impair a patient's quality of life. This review summarizes the association between stress and itch, elucidates the mechanism by which these two phenomena influence one another, and explores treatment modalities that aim to reduce stress-induced itch.

METHODS

A complete search of the PubMed and Google Scholar databases was completed and literature pertinent to this review was compiled.

FINDINGS

Both acute and chronic stress can significantly affect itch in healthy individuals and in those diagnosed with itchy skin diseases as well as systemic diseases, thus resulting in a vicious cycle in which stress exacerbates itch and vice versa. The mechanisms by which stress induces or aggravates itch include both central and peripheral activation of the hypothalamic-pituitary-adrenal axis and sympathetic nervous system. Activation of these systems, in turn, affects the mast cells, keratinocytes, and nerves that secrete neuropeptides, such as substance P, nerve growth factor, acetylcholine, histamine, and itchy cytokines. A dysfunctional parasympathetic response is thought to be involved in the chronic stress/itch response. Brain structures associated with emotion, such as the limbic system and periaqueductal gray, which work on the descending facilitation of itch, play a significant role in stress-induced itch.

IMPLICATIONS

As specific brain structures are associated with stress, drug treatments targeting these areas (ie, γ-aminobutyric acid-ergic drugs, serotonin and norepinephrine reuptake inhibitors) may help to modulate itch. Stress can also be combatted using nonpharmacologic treatments such as cognitive-behavioral therapies and stress-relieving holistic approaches (eg, yoga, acupuncture).

Itching as the onset of pain (part 1)

PAIN is a psychophysiological reaction of an organism that occurs with severe irritation of the sensitive nerve endings embedded in organs and tissues. And also pain is the body’s protective reaction. It is signaling about a discomfort and triggers an appropriate response by the body to eliminate the cause of the pain. Pain is one of the earliest symptoms of some diseases [84]. ITCHING – an unpleasant sensation of irritation, heartburn and tingling in any area of the skin caused by various factors (exposure to chemicals, bacteria, parasites). This feeling is often manifested by the urgent need to rub or scratch some areas of the skin (or mucous membrane) [85]. When considering the pathogenesis of these concepts, a sufficiently large resemblance to the realization of mechanisms of origin, or a certain identity thereof is revealed. The question naturally arises whether itching is an early manifestation of pain, especially in those groups of diseases that are not characterized by pain. Pathology of the hematopoietic system is not accompanied by a symptom such as pain. But for conditions such as iron overload, iron deficiency or polycythemia, itching is a clear symptom. The unknown etiology of chronic itching of the skin is indicative of histological examination of the skin in order to exclude skin lymphoma. One of the least understood mechanisms of itching is itching associated with malignant solid tumors. What pain that itching is a subjective sensation that can have an acute or chronic course, a clear intensity and a very significant impact on quality of life, especially in the case of comorbidity. In addition, the question arises whether itching is an early manifestation of pain, especially in those groups of diseases that are not characterized by pain. How can a doctor manage itching effectively to prevent complications? To these and other questions, we have attempted to systematize the manifestations of itching in pathologies of organs and systems that are not traditionally accompanied by pain.

The NK1 receptor antagonist serlopitant for treatment of chronic pruritus

Introduction: Pruritus is a common symptom associated with several potential underlying causes, including both dermatologic and systemic diseases; it can also occur without an identifiable cause. Current treatment options are limited and most patients experience impaired quality of life. Serlopitant is a neurokinin 1 (NK₁) receptor antagonist under development for the treatment of pruritus associated with various dermatologic conditions and chronic pruritus of unknown origin. Areas covered: This review describes the epidemiology and unmet needs of patients with chronic pruritus, focusing specifically on patients with prurigo nodularis, psoriatic itch, and chronic pruritus of unknown origin; the rationale for targeting the NK₁ receptor for treatment of chronic pruritus; and the clinical development of serlopitant, including efficacy and safety data from completed phase II studies. Expert opinion: There is an unmet need for novel, safe, and effective therapies to treat chronic pruritus. Serlopitant has shown promising efficacy, safety, and tolerability across different patient populations, including adolescents and elderly patients. In contrast to less convenient administration options, serlopitant is a once-daily oral tablet, which is expected to facilitate compliance.

Presence and characteristics of senile pruritus among Danish elderly living in nursing homes

Aim:

To explore the pattern of occurrence and characteristics of senile pruritus among elderly living in nursing homes in the Northern region of Denmark.

Materials & methods:

A Danish questionnaire was developed and distributed to six nursing homes from which 46 residents participated.

Results:

The prevalence of chronic itch was 28.9%. Evening–night and autumn–winter with an average daily itch of 30 min were reported. Itch interfered with night sleep and daily activities. Scratching was common with 61.5% accompanying scratch marks. Half of participants reported Xerosis. Cream, cold compress and cold shower were found to be the most effective remedies for itch relief.

Conclusion:

The present study revealed a high prevalence of chronic pruritus including cases of senile pruritus that needs further exploration for treatment or preventive strategies.

Senile pruritus is chronic itch of unknown origin among the elderly. The occurrence and characteristics among Danish nursing home residents was not known. We developed a Danish questionnaire and distributed it to 6 nursing homes, where 46 residents participated. We found a high prevalence of chronic itch (28.9%). Disturbing itch was reported in evening–night and autumn–winter. Itch interfered with night sleep and daily activities. Scratching was common with scratch marks. Showering precipitated itch, while cold shower was a reliever. Further studies are required to enhance the knowledge about senile pruritus and prevention or treatment strategies for elderly living in nursing homes.

Understanding the Burden of Atopic Dermatitis in Africa and the Middle East

Atopic dermatitis (AD) is a common inflammatory skin disease characterized by intensely pruritic lesions. The prevalence of atopic dermatitis is increasing in developing regions, including Africa and the Middle East. However, these regions are underrepresented in the dermatology literature, and a better understanding of the growing burden of atopic dermatitis in Africa and the Middle East is necessary. Herein, we summarize current knowledge on atopic dermatitis epidemiology, disease burden, and treatment options in Africa and the Middle East, highlighting the unmet needs of patients in these regions. With these needs in mind, we provide clinical recommendations for appropriate management of atopic dermatitis in Africa and the Middle East. FUNDING: Pfizer Inc. Plain language summary available for this article.

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

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

Pruritus in patients with solid tumors: an overlooked supportive care need

PURPOSE

Pruritus is a common symptom in cutaneous malignancies, but its impact on patients with solid tumors is unclear. We explored the impact and management of pruritus in patients with solid tumors, using patient-reported outcomes (PRO) data from a real-world registry.

METHODS

From 2006 to 2011, patients seen in the Duke Cancer Institute reported their symptoms via the Patient Care Monitor v2.0, a validated PRO tool that includes a 0-10-point question about pruritus severity. From > 25,000 encounters, 203 patients reported severe pruritus (> 6/10) on at least one visit and 506 total visits were abstracted where patients reported either moderate or severe pruritus (> 3/10). From this cohort, we abstracted demographics, diagnosis, stage, cancer therapy, anti-pruritic therapy, and clinicians' responses.

RESULTS

Mean age was 59.8 (SD 13.3), 134 (66%) were female, 125 (62%) were Caucasian, and 65 (32%) were African American. Breast cancer was the most common tumor (36.5%), followed by lung cancer (23.2%). Mean pruritus severity score was 6.8 (SD 1.8) for patients on chemotherapy, 6.9 (SD 1.8) for patients on targeted therapy alone or in combination, and 7.1(SD 1.8) for patients off treatment. Overall, 67% of patients reported at least two episodes of moderate-severe pruritus (mean # of visits 4.2 (SD 2.7)). Despite frequent report of severe and persistent pruritus, this was mentioned in just 28% of clinician notes and an intervention was recommended/prescribed in only 7% of visits.

CONCLUSIONS

Pruritus is an under-addressed symptom in patients with solid tumors. Additional research is needed to understand the burden of pruritus in affected populations.

The association of patient and burn characteristics with itching and pain severity

INTRODUCTION

Itch after burn injury causes significant distress to patients and can hamper functional recovery. Itching can persist on a time scale ranging from several weeks to even years after injury. In this study, we sought to determine predictors of itching after burn injury.

METHODS

We compared itch and pain severity among patients included in a burn registry at a level 1 trauma center. Both itch and pain severity was based on a 5-point scale. ANOVA, chi-squared, and multivariate analyses were performed to determine predictors of itch and pain severity.

RESULTS

Of the 1159 patients enrolled in the registry, 58% were male and 42% female, with a median age (IQR) of 27 (8-47) years. Most patients were diagnosed with 2nd degree superficial (41%) or deep (43%) burns. Upper extremities were the most common location of burn injury (59%), followed by lower extremities (31%), trunk (22%), and face/neck (20%). More than half (53%) of enrolled patients reported itching, ranging from minimal (19%) to severe (7%) itching. Multivariate analyses revealed age, sex (female), extent of burn injuries, and location (face/neck) to be predictors of itch after burn. Predictors of pain after burn were slightly different: age, extent of burn, and depth of burn.

CONCLUSION

Pain and itch after burn injuries are predicted by slightly different variables, presumably secondary to different underlying mechanisms. We conclude that age, sex (female), extent of burn injuries (total body surface area %), and injuries to the face/neck predict itching of greater severity. Patients with burn injuries that match these parameters would require greater care and closer follow up to reduce itching after healing.

Cross-European validation of the ItchyQoL in pruritic dermatoses

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

S2k Guidelines for the diagnosis and treatment of chronic pruritus - update - short version

Associated with a host of different diseases, pruritus is a cardinal symptom that poses an interdisciplinary diagnostic and therapeutic challenge. Over time, that symptom may progress independently of the initial cause, thus losing its function as a warning sign and turning into a clinically relevant disease of its own. In Germany, approximately 13.5 % of the general population are affected by chronic pruritus, with an incidence of 7 %. All forms of chronic pruritus require targeted treatment consisting of (a) diagnosis and management of the underlying disease, (b) dermatological treatment of primary or secondary (for example, dry skin, scratch lesions) symptoms, (c) symptomatic antipruritic treatment, and (d) psychological/psychotherapeutic treatment in case of an underlying or associated psychological or psychosomatic condition. Medical care of patients with chronic pruritus should therefore include an interdisciplinary approach, in particular with respect to diagnosis and therapy of the underlying disease as well as in terms of the management of treatment and adverse events. The objective of the present interdisciplinary guidelines is to define and standardize diagnostic and therapeutic procedures in patients with chronic pruritus. This is a short version of the current S2 guidelines on chronic pruritus. The long version may be found at www.awmf.org.

Does transcutaneous electrical nerve stimulation have an antipruritic effect in lichen planus? A randomized clinical trial

BACKGROUND

Lichen planus (LP) is a moderately prevalent inflammatory disorder that affects the skin and the oral mucosa, leading to a characteristic appearance and causing severe itching.

AIM

To assess the potency of transcutaneous electrical nerve stimulation (TENS) as an antipruritic line of treatment in patients with LP.

METHODS

We enrolled 30 patients with LP who had a history of recurrent relapses of confined pruritus forcing them to scratch or rub the affected area intensively. Patients were treated with TENS three times per week for 4 weeks. Severity of itching was estimated by visual analogue scale (VAS) and Dermatology Life Quality Index (DLQI).

RESULTS

There was a statistically significant decline in mean VAS score at weeks 2 and 4 of treatment compared with baseline (P < 0.05, with 74% of participants having an improvement of > 50%. Significant improvement in itching intensity also resulted in better quality of life, as there was also a significant reduction in median DLQI at weeks 2 and 4 of therapy compared with baseline (P < 0.05), with 65% of patients having an improvement of > 50% in median DLQI score.

CONCLUSION

TENS may be an alternative safe treatment for LP-induced itching.

Itch and psyche: psychiatric aspects of pruritus

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

The Influence of Reactive Oxygen Species and Glucocorticoids on Dry Skin in a Mouse Model of Arthritis

BACKGROUND

Dry skin induced by rheumatoid arthritis (RA) causes itching, which negatively influences a patient's quality of life. We previously reported that mast cells are related to dry skin in arthritic mice. However, the mechanism of mast cell activation is unclear. In this study, we examined the mechanism underlying the formation of dry skin induced by mast cells in arthritis that involves thymic stromal lymphopoietin (TSLP), neutrophils, reactive oxygen species (ROS), and glucocorticoids.

METHODS

Mice with DBA/1JJmsSlc collagen-induced arthritis were treated with inhibitors or neutralizing antibodies. We measured transepidermal water loss (TEWL) to examine the modulating signal of mast cells.

RESULTS

TEWL, the number of mast cells, and the plasma levels of TSLP, ROS, and corticosterone in the arthritic mice were increased when compared with the control mice. However, the mice treated with TSLP- and neutrophil-neutralizing antibodies and ROS and glucocorticoid receptor inhibitors (N-acetyl-L-cysteine [NAC] and RU-486, respectively) experienced an improvement. The ameliorating effect was most remarkable following treatment with NAC + RU-486.

CONCLUSION

This study suggested that inhibiting ROS and glucocorticoids is important to ameliorate dry skin in arthritis, which may provide a novel treatment option for dry skin in RA patients.

Pruritus: Progress toward Pathogenesis and Treatment

Pruritus, the most common cutaneous symptom, is widely seen in many skin complaints. It is an uncomfortable feeling on the skin and sometimes impairs patients' quality of life. At present, the specific mechanism of pruritus still remains unclear. Antihistamines, which are usually used to relieve pruritus, ineffectively work in some patients with itching. Recent evidence has suggested that, apart from histamine, many mediators and signaling pathways are involved in the pathogenesis of pruritus. Various therapeutic options for itching correspondingly have been developed. In this review, we summarize the updated pathogenesis and therapeutic strategies for pruritus.

Validity and reliability of the Urdu version of the 5D itching scale to assess pruritus among patients with chronic kidney disease in Pakistan

Background

Chronic kidney disease (CKD) has become a major public health issue worldwide in the past few years. Pruritus is a common, well-recognized complication often seen in patients with chronic renal failure. For assessment of pruritus, different tools are used but these tools are unable to identify the changes and variations in the severity of pruritus. The aim of our study was to validate the Urdu-version of the Urdu-version of the 5D itch scale among patients suffering from chronic kidney disease in Pakistan.

Method

The 5D itch scale was translated from English into Urdu following translation guidelines for translation. Face and content validity was determined by a panel of experts and piloted. For retest, the Urdu version of the 5D itch scale was administered at baseline and two weeks.

Results

A total of 50 participants with end stage renal disease were recruited, and of these, 64% were males. Exploratory factor analysis revealed that the 5D–IS had 2-factor loadings: “Pattern and activity” and “Distribution” with Kaiser–Mayer–Olkin (KMO) = 0.802, Bartlett’s test of sphericity was significant (df = 28, p < 0.001). At test re-test, Cronbach’s alpha was 0.914, while the intra class correlation was 0.9160 (95% confidence interval 0.941–0.975), which is a highly significant correlation (p < 0.0001).

Conclusion

The Urdu version of the 5D itch scale was found to be a valid and reliable instrument for assessing pruritus and its severity in patients with chronic kidney disease in Pakistan.

Electronic supplementary material

The online version of this article (10.1186/s12882-017-0717-0) contains supplementary material, which is available to authorized users.

Global Burden of Skin Disease: Inequities and Innovations

PURPOSE OF REVIEW

We review the current understanding of the burden of dermatological disease through the lens of the Global Burden of Disease project, evaluate the impact of skin disease on quality of life in a global context, explore socioeconomic implications, and finally summarize interventions towards improving quality of dermatologic care in resource-poor settings.

RECENT FINDINGS

The Global Burden of Disease project has shown that skin diseases continue to be the 4th leading cause of nonfatal disease burden world-wide. However, research efforts and funding do not match with the relative disability of skin diseases. International and national efforts, such as the WHO List of Essential Medicines, are critical towards reducing the socioeconomic burden of skin diseases and increasing access to care. Recent innovations such as teledermatology, point-of-care diagnostic tools, and task-shifting help to provide dermatological care to underserved regions in a cost-effective manner.

SUMMARY

Skin diseases cause significant non-fatal disability worldwide, especially in resource-poor regions. Greater impetus to study the burden of skin disease in low resource settings and policy efforts towards delivering high quality care are essential in improving the burden of skin diseases.

Development of a transformation model to derive general population-based utility: Mapping the pruritus-visual analog scale (VAS) to the EQ-5D utility

RATIONALE, AIMS, AND OBJECTIVES

Although nonpreference-based disease-specific measures are widely used in clinical studies, they cannot generate utilities for economic evaluation. A solution to this problem is to estimate utilities from disease-specific instruments using the mapping function. This study aimed to develop a transformation model for mapping the pruritus-visual analog scale (VAS) to the EuroQol 5-Dimension 3-Level (EQ-5D-3L) utility index in pruritus.

METHODS

A cross-sectional survey was conducted with a sample (n = 268) drawn from the general population of South Korea. Data were randomly divided into 2 groups, one for estimating and the other for validating mapping models. To select the best model, we developed and compared 3 separate models using demographic information and the pruritus-VAS as independent variables. The predictive performance was assessed using the mean absolute deviation and root mean square error in a separate dataset.

RESULTS

Among the 3 models, model 2 using age, age squared, sex, and the pruritus-VAS as independent variables had the best performance based on the goodness of fit and model simplicity, with a log likelihood of 187.13. The 3 models had similar precision errors based on mean absolute deviation and root mean square error in the validation dataset. No statistically significant difference was observed between the mean observed and predicted values in all models.

CONCLUSIONS

In conclusion, model 2 was chosen as the preferred mapping model. Outcomes measured as the pruritus-VAS can be transformed into the EQ-5D-3L utility index using this mapping model, which makes an economic evaluation possible when only pruritus-VAS data are available.