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

From Compression to Itch: Exploring the Link Between Nerve Compression and Neuropathic Pruritus

Neuropathic itch is a type of chronic pruritus resulting from neural dysfunction along the afferent pathway. It is often accompanied by abnormal sensations such as paresthesia, hyperesthesia, or hypoesthesia. This condition, which may involve motor or autonomic neural damage, significantly impacts patients' quality of life, causing severe itch and associated comorbidities such as depression, disrupted sleep, and social strain. Neuropathic itch accounts for 8% of chronic pruritus cases, though this may be underestimated. This comprehensive review focuses on nerve impingement as the primary pathophysiological mechanism for various forms of neuropathic itch including brachioradial pruritus (BRP), notalgia paresthetica (NP), and anogenital itch. BRP, often seen in middle-aged white women, manifests as pruritus in the dorsolateral forearms typically exacerbated by ultraviolet (UV) exposure and related to cervical spine pathology. NP, prevalent in middle-aged women, presents as pruritus in the upper back due to thoracic spine nerve compression. Anogenital pruritus, affecting 1-5% of adults, is often linked to lumbosacral spine issues after ruling out dermatologic conditions such as lichen sclerosus or lichen simplex chronicus. The pathophysiology of neuropathic itch involves both peripheral and central mechanisms, with nerve damage being a key factor. Diagnosis requires a thorough history, physical examination, and potentially imaging studies. Topical agents such as menthol, capsaicin, and lidocaine are used for mild cases, while systemic medications such as gabapentin, pregabalin, and antidepressants are prescribed for moderate to severe cases; however, no US Food and Drug Administration (FDA)-approved therapies currently exist specifically for neuropathic itch. Understanding the underlying neural dysfunction and appropriate therapeutic strategies is crucial for managing neuropathic itch effectively.

Relationship between pruritus and sleep in participants with primary biliary cholangitis in the Phase 2b GLIMMER trial

BACKGROUND

Cholestatic pruritus and fatigue are debilitating conditions associated with primary biliary cholangitis (PBC) and can significantly impact patients' quality of life. Pruritus in PBC often worsens at night and patients frequently report sleep disturbance, which contributes to cognitive symptoms and fatigue. Linerixibat is an ileal bile acid transporter inhibitor in clinical development for the treatment of pruritus associated with PBC and was recently assessed versus placebo in the Phase 2b GLIMMER trial. This post-hoc analysis assesses the relationship between pruritus severity and sleep disturbance in participants of GLIMMER regardless of treatment group.

METHODS

GLIMMER (NCT02966834), a multicenter, double-blind, randomized, placebo-controlled trial, recruited 147 patients with PBC and moderate-to-severe pruritus. Following 4 weeks single-blind placebo, patients (randomized 3:1) received linerixibat or placebo for 12 weeks (to Week 16). Participants graded their itch (twice daily) and its interference with sleep (once daily) in an electronic diary using a 0-10 numerical rating scale (NRS). Weekly and monthly itch scores were calculated as the mean of the worst daily itch score over the respective time period. At study visits, participants completed the 5-D itch scale and the PBC-40 quality of life questionnaire, both of which contain an item specific to itch-related sleep disturbance. The impact of pruritus on sleep was assessed post hoc through correlations between the changes in NRS, 5-D itch, and PBC-40.

RESULTS

Strong correlations were found between change from baseline in weekly itch and sleep NRS scores (r = 0.88 [95% confidence interval (CI): 0.83; 0.91]) at the end of treatment (Week 16), as well as in monthly itch and sleep NRS scores (r = 0.84 [95% CI: 0.80; 0.87]). Patients with improved weekly pruritus score severity category demonstrated reduced perceived sleep interference on average. Itch responders (≥2-point improvement in weekly itch score from baseline) displayed larger improvements in weekly sleep NRS score, 5-D itch, and PBC-40 sleep items, than itch non-responders (<2-point improvement).

CONCLUSIONS

A strong correlation exists between changes in pruritus severity and sleep interference in patients with PBC; pruritus reduction could generate concomitant improvement in sleep.

Investigation of the Impact of Atopic Dermatitis (AD) on Stress, Depression, Anxiety, and Suicidal Ideation: A Systematic Review and Meta-Analysis

Skin inflammation, known as atopic dermatitis (AD), is often accompanied by various psychological disorders. The objective of this meta-analysis was to assess the impact of AD on stress, depression, anxiety, and suicidal ideation. A comprehensive search was conducted using nine databases. The risk of bias was evaluated using the Newcastle-Ottawa Scale (NOS). ORs were generated to analyze the results. Thirty-one articles met the requirements for inclusion, with 25 deemed of good quality and six of fair quality. A positive association was observed between AD and stress (OR = 1.546; 95% CI: 1.445-1.653; p = 0.000), depression (OR = 1.140; 95% CI: 1.127-1.153; p = 0.000), anxiety (OR = 1.080; 95% CI: 1.063-1.097; p = 0.000), and suicidal ideation (OR = 1.158; 95% CI: 1.144-1.172; p = 0.000). Interestingly, a significant publication bias was found in the outcomes related to depression and anxiety. This analysis suggests that AD significantly impacts the psychological well-being of patients. Stress, depression, anxiety, and suicidal ideation are among the mental health issues commonly associated with AD. Therefore, clinicians should consider mental health evaluations for patients with AD.

The skin-brain connection and pleasant touch as supportive care for psychocutaneous disorders

Psychodermatology is a subdiscipline of dermatology at the intersection of dermatology, psychiatry, and psychology. In dermatology clinical practice, patients may present with skin disease that affects their mental health, or skin disorders induced or worsened by psychological/psychiatric problems so there is a need for specialised education of dermatologists, as well as multidisciplinary teams, to achieve better management of these patients. Understanding the interaction between the central nervous system and the skin underlying psychocutaneous disorders could help identify alternative therapies that may improve patient well-being. The concept of pleasurable touch has received increasing attention following the discovery of C-tactile (CT) fibres. While afferent C-fibre stimulation is usually associated with pain, temperature, or itch, CT-fibres are stimulated optimally by a stimulus not in the nociceptor range but by a gentle, low-force stroking. As this affective touch may counteract unpleasurable sensations, such as pain and itch, and elicit positive feelings, the potential benefits of gentle touch and massage are interesting for dermatological, especially psychocutaneous, disorders. Here we provide an overview of the skin-brain connection to help understand the benefits of touch and massage, as illustrated with studies on atopic dermatitis and burns, as an adjunct to dermatological treatment for improving patient well-being and optimising treatment outcomes.

Association of pruritus with sleep in patients with psoriasis and chronic spontaneous urticaria: A cross-sectional study

Background

Pruritus is a frequent complaint associated with various inflammatory dermatoses. Sleep is often disturbed because of pruritus but the impact of severity and diurnal pattern of pruritus has not been studied so far.

Objectives

To estimate the prevalence of nocturnal itch (NI) and its association with itch severity, sleep disturbance and quality of life (QoL) compared with non-NI in chronic plaque psoriasis (CPP) and chronic spontaneous urticaria (CSU).

Methods

We performed a cross-sectional study in patients aged ≥18 years with CPP or CSU for at least 6 weeks. A comprehensive in-house questionnaire designed for study formed the basis for categorizing patients into NI and non-NI. Validated instruments like visual analog scale, pruritus grading system, General Sleep Disturbance Scale, and Dermatology life quality index were used to assess itch severity, sleep, and QoL.

Results

A total of 255 patients (CPP: 131; CSU: 124) were included in this study. Prevalence of NI was 43.5% (95% confidence interval: 34.9%-52.4%) in CPP and 29% (95% confidence interval: 21.2%-37.9%) in CSU. NI was strongly associated with higher pruritus grading system scores in CSU and CPP (regression coefficient = 1.5, P =0.004 and regression coefficient = 1.3, P =0.004, respectively), with impaired sleep (OR = 2.97, P = 0.025) in CPP and with itch-affected sleep in CSU. Itch severity was associated with impaired sleep; however, the association was modified by the presence of NI in CSU patients.

Conclusion

Nocturnal itch is prevalent in chronic dermatoses and significant for sleep deficit and impaired QoL. Early screening and management of sleep disturbance among patients presenting with nocturnal itch should be routinely undertaken.

Mental health and its influencing factors of maintenance hemodialysis patients: a semi-structured interview study

BACKGROUND

Maintenance hemodialysis (MHD) is a commonly used renal replacement therapy for end-stage renal disease patients. MHD patients have undergone multiple physiological stressors, which may cause physical problems and affect their mental health; however, few qualitative studies have been done on the mental health of MHD patients. Such qualitative research becomes the basis for further quantitative research and is critical to validating its results. Therefore, the current qualitative study used a semi-structured interview format, and aimed to explore the mental health and its influencing factors of MHD patients who are not receiving intervention treatment to determine how best to ameliorate their mental health.

METHODS

Based on the application of Grounded Theory, semi-structured face-to-face interviews were conducted with 35 MHD patients, following consolidated criteria for reporting qualitative studies (COREQ) guidelines. Two indicators (emotional state and well-being) were used to assess MHD patients' mental health. All interviews were recorded, after which two researchers independently performed data analyses using NVivo.

RESULTS

Acceptance of disease, complications, stress and coping styles, and social support were found to be the influencing factors of MHD patients' mental health. High acceptance of disease, healthy coping styles, and high social support were positively correlated with mental health. In contrast, low acceptance of disease, multiple complications, increased stress, and unhealthy coping styles were negatively correlated with mental health.

CONCLUSION

One's acceptance of the disease played a more significant role than other factors in affecting MHD patients' mental health.

Glial Cells and Itch: Possible Targets for Novel Antipruritic Therapies

Glial cells, which are the non-neuronal cells of the nervous system, play essential roles in brain development, homeostasis, and diseases. Glial cells have attracted attention because of their active involvement in many neurological disorders. In recent years, substantial progress has been made in our understanding of the roles of glial cells in the pathogenesis of itch. Mechanistically, central and peripheral glial cells modulate acute and chronic pruritus via different mechanisms. In this review, we present the current knowledge about the involvement of glial cells in the modulation of itch processing and the mechanism of glial cell activation under itch stimuli. Targeting glial cells may provide novel approaches for itch therapy.

Association between Pruritus and Psychosocial Well-being: A Population-based Study among 6,809 Subjects

Pruritus has an extensive impact on functional, social and psychosocial behaviour. The association between pruritus and psychological well-being has mostly been studied among selected patient groups, whereas population-based studies are lacking. The aim of this study was to determine the association between pruritus and insomnia, quality of life, depression and anxiety at the population level in the general population. A cross-sectional population-based study was conducted in 2012 to 2013. Study subjects (n = 6,809) belonging to the Northern Finland Birth Cohort 1966 Study participated in a large follow-up study at the age of 45-47 years. They completed an extensive health questionnaire including questions on pruritus and several previously validated questionnaires regarding symptoms of psychosocial well-being. Pruritus affected 19.9% of the study subjects weekly, being more common in women than in men (p < 0.001). A significant association was found between both localized and generalized pruritus and symptoms of insomnia, depression, anxiety and decreased quality of life. The association was seen even in those with mild psychological symptoms/insomnia, and it affected both sexes. The severity of psychological symptoms increased with increasing frequency of pruritus. In conclusion, pruritus has a multiple effect on psychosocial well-being. Physicians should consider possible psychosocial symptoms in patients with pruritus.

Psychologic interventions in patients with the chronic dermatologic itch in atopic dermatitis and psoriasis: A step forward with family constellations seminars

Chronic itch is a complex psychophysiological sensation, which can severely affect the quality of life in patients with atopic dermatitis and psoriasis. Itch depends on the irritation of receptors in the skin and the processing of sensory information in the central nervous system. Severe itch leads to activation and later on to disruption of the stress response, resulting in disorders of skin repair, functional and microstructural changes in the areas of the central nervous system that are responsible for the perception of itch. Psychosocial stress can be an essential factor, activating neurohumoral mechanisms which lead to increased itch and scratch, exacerbating skin damage. Patients with chronic itch often have sleep disorders, increased irritability, and depletion of the nervous system. They are characterized by disrupting social relationships, high incidence of anxiety, depressive disorders, and suicidal tendencies. Psychological methods of intervention can effectively influence various mechanisms in the pathogenesis of itch and scratch and improve social functioning in patients with chronic dermatological itch. In this mini-review, we discuss family constellation seminars as an effective method of psychological intervention that can reduce the intensity of itch, and improve sleep and performance in patients with atopic dermatitis and psoriasis. This method is insufficiently described in previous reviews of psychological interventions in atopic dermatitis and psoriasis patients. The positive impact of family constellations seminars in patients with chronic dermatological itch may be related to reducing stress by improving understanding of the family situation, appropriate management of family secrets, and enhancing interactions with the social environment.

Automated scratching detection system for black mouse using deep learning

The evaluation of scratching behavior is important in experimental animals because there is significant interest in elucidating mechanisms and developing medications for itching. The scratching behavior is classically quantified by human observation, but it is labor-intensive and has low throughput. We previously established an automated scratching detection method using a convolutional recurrent neural network (CRNN). The established CRNN model was trained by white mice (BALB/c), and it could predict their scratching bouts and duration. However, its performance in black mice (C57BL/6) is insufficient. Here, we established a model for black mice to increase prediction accuracy. Scratching behavior in black mice was elicited by serotonin administration, and their behavior was recorded using a video camera. The videos were carefully observed, and each frame was manually labeled as scratching or other behavior. The CRNN model was trained using the labels and predicted the first-look videos. In addition, posterior filters were set to remove unlikely short predictions. The newly trained CRNN could sufficiently detect scratching behavior in black mice (sensitivity, 98.1%; positive predictive rate, 94.0%). Thus, our established CRNN and posterior filter successfully predicted the scratching behavior in black mice, highlighting that our workflow can be useful, regardless of the mouse strain.

New insight into chronic pruritus' characteristics and association with the demographic characteristics and sleep of community-dwelling older adults in Taiwan

This study aimed to understand the characteristics of chronic pruritus (CP), its correlations with sleep quality and demographic characteristics, and its impacts on sleep of older adults. This study used convenience sampling to recruit adults aged 65 or older and living at home. The prevalence rate of CP in older adults was 25.8%. Most subjects with CP reported mild pruritus on 1-2 anatomical parts, especially the lower extremities. Overall, the five domains of CP were correlated with the seven components of sleep quality (r > .14; p > .05) except for sleep disturbance. The global itchy scores were significantly different between different sexes, educational attainments, and marital statuses (p<.05-.001). CP, sex, and the number of comorbid diseases significantly contributed to global sleep quality (β = .26, -.19, .15, respectively; .000 ≤ p ≤ .011). This study provides new insight into the correlations of CP with marital status and educational attainment.

Validation of the 5-D Itch Scale in Three Ethnic Groups and Exploring Optimal Cutoff Values Using the Itch Numerical Rating Scale

Background

Chronic pruritus is a common and distressing condition that has serious emotional and psychosocial consequences. Due to its subjective nature, self-report questionnaires are widely implemented as cost-effective measures to gauge the severity of chronic pruritus. The current study is aimed at validating the 5-D itch scale in three ethnic groups—Black, Asian, and Hispanic—with the well-validated Itch Numerical Rating Scale (NRS) and Worst Itch NRS (WI-NRS) and developing its cutoff value using receiver operating characteristics (ROC) and inspection of the area under the curve (AUC) across ethnic groups. At the same time, it is aimed at comparing the concurrent prevalence of itch and depression in these populations, who often form ethnic minorities in many countries. The current study addresses the knowledge gap of cultural adaptation of the 5-D pruritus scale for greater usage.

Methods

Community samples of three ethnic groups were recruited from an online platform of Qualtrics and administered the self-report questionnaires of Itch-NRS, 5-D itch scale, and Patient Health Questionnaire-9 (PHQ-9) to measure their pruritus domains, itch intensity, depression screening, and its severity. Informed consent was obtained from all participants. Subgroup analysis was conducted, including concurrent validity and cutoff values compared between each ethnic group. Concurrent prevalence of itch and depression was evaluated using the cutoff value of Itch-NRS and PHQ-9.

Result

A total of 2323 participants were included in the study. A significant positive correlation (p < 0.001) was found between the Itch-NRS, WI-NRS, and 5-D itch scale. The cutoff value of the 5-D itch scale was established for the three ethnic groups using ROC, with a cutoff value of Itch-NRS as a reference.

Conclusions

The 5-D itch scale has demonstrated sound psychometric properties in three ethnic groups and is closely related to Itch-NRS. The analysis of the cutoff value of the 5-D itch scale suggests that different cutoff values should be considered to reduce the inflation of pruritus severity.