The characteristics of nocturnal scratching in adults with atopic dermatitis

The Circadian Rhythm of Itching among 241 Adults with Atopic Dermatitis: A Cross-sectional Study

The pattern of itching in patients with atopic dermatitis has not been systematically studied. Therefore, this study aimed to assess the pattern of itching in adults with atopic dermatitis using questionnaires to assess for a circadian rhythm of itching in participating patients at a single institution (n = 241). A self-report questionnaire was used to assess circadian rhythm and intensity of itching in patients. In addition, the patients' disease severity (Eczema Area and Severity Index [EASI]) and quality of life (Dermatology Life Quality Index [DLQI]) were assessed. Itching occurred most frequently (74.69%) and with the greatest severity (62.66%) between 20:00 and 00:00, and the least number of patients (25.31%) experienced itching between 04:00 and 08:00. The DLQI and EASI scores both correlated with the average and maximum itch intensity (r = 0.582, r = 0.533, respectively; r = 0.539, r = 0.517, respectively; p < 0.001). The DLQI and EASI scores were associated with average itch intensity (B = 0.179, B = 0.204, respectively; 95% CI: 0.112 to 0.246, 95% CI: 0.096 to 0.313, respectively; p < 0.001), and the EASI score was associated with males and family history (B = 0.285, B = 0.287, respectively; 95% CI: 0.094 to 0.476, 95% CI: 0.096 to 0.478, respectively; p = 0.003). Adult patients with atopic dermatitis exhibited a circadian rhythm of itching; these study results could positively impact treatment approaches.

Polysomnographic characteristics of sleep in adults with and without physician-diagnosed atopic dermatitis: results from the Study of Health in Pomerania

PURPOSE

To analyze sleep characteristics as measured with polysomnography (PSG) in adults from the general population with and without physician-diagnosed atopic dermatitis (AD).

METHODS

We analyzed data from participants from the German population-based Study of Health in Pomerania (SHIP) TREND-0. AD was diagnosed in a standardized skin examination. The following polysomnographic parameters were measured: total sleep duration (min), sleep latency (min), wake after sleep onset (WASO; min), rapid eye movement (REM) latency (min), sleep efficiency (%), total number of wakefulness and movement episodes, stages of sleep (%), and apnea-hypopnea index (AHI). Additionally, the subjective sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). We compared sleep characteristics of participants with and without AD.

RESULTS

Among 1187 participants, 47 (4.0%) had AD. We found no differences between participants with and without AD in any of the analyzed PSG parameters except for the total number of wakefulness and movement episodes and the percentage of REM sleep. Participants with AD had a higher number of wakefulness and movement episodes, and a lower proportion of REM sleep compared to those without AD. Regarding subjective sleep parameters, no significant differences were found between participants with and without AD.

CONCLUSION

Our data do not provide evidence for poor sleep quality in individuals with AD. Major limitations of the study include the unavailability of data on AD severity and the small number of participants with AD. Larger-scaled longitudinal studies considering disease severity and specific AD symptoms with an effect on sleep are required.

The circadian metabolome of atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by dry, pruritic skin. Several studies have described nocturnal increases in itching behavior, suggesting a role for the circadian rhythm in modulating symptom severity. However, the circadian rhythm of metabolites in the skin and serum of patients with AD is yet to be described.

OBJECTIVE

We sought to assess circadian patterns of skin and serum metabolism in patients with AD.

METHODS

Twelve patients with moderate to severe AD and 5 healthy volunteers were monitored for 28 hours in a controlled environment. Serum was collected every 2 hours and tape strips every 4 hours from both lesional and nonlesional skin in participants with AD and location-, sex-, and age-matched healthy skin of controls. We then performed an untargeted metabolomics analysis, examining the circadian peaks of metabolism in patients with AD.

RESULTS

Distinct metabolic profiles were observed in AD versus control samples. When accounting for time of collection, the greatest differences in serum metabolic pathways were observed in arachidonic acid, steroid biosynthesis, and terpenoid backbone biosynthesis. We identified 42 circadian peaks in AD or control serum and 17 in the skin. Pathway enrichment and serum-skin metabolite correlation varied throughout the day. Differences were most evident in the late morning and immediately after sleep onset.

CONCLUSIONS

Although limited by a small sample size and observational design, our findings suggest that accounting for sample collection time could improve biomarker detection studies in AD and highlight that metabolic changes may be associated with nocturnal differences in symptom severity.

A Sensorised Glove to Detect Scratching for Patients with Atopic Dermatitis

In this work, a lightweight compliant glove that detects scratching using data from microtubular stretchable sensors on each finger and an inertial measurement unit (IMU) on the palm through a machine learning model is presented: the SensorIsed Glove for Monitoring Atopic Dermatitis (SIGMA). SIGMA provides the user and clinicians with a quantifiable way of assaying scratch as a proxy to itch. With the quantitative information detailing scratching frequency and duration, the clinicians would be able to better classify the severity of itch and scratching caused by atopic dermatitis (AD) more objectively to optimise treatment for the patients, as opposed to the current subjective methods of assessments that are currently in use in hospitals and research settings. The validation data demonstrated an accuracy of 83% of the scratch prediction algorithm, while a separate 30 min validation trial had an accuracy of 99% in a controlled environment. In a pilot study with children (n = 6), SIGMA accurately detected 94.4% of scratching when the glove was donned. We believe that this simple device will empower dermatologists to more effectively measure and quantify itching and scratching in AD, and guide personalised treatment decisions.

Nocturnal Scratching and Quality of Sleep in Children with Atopic Dermatitis

Itching due to atopic dermatitis causes sleep disorders in children, but its pathology is unknown. The aim of this study is to investigate nocturnal scratching as an indirect index of itching during sleep and its relationship with depth of sleep in children with atopic dermatitis. Nocturnal scratching was measured in a total of 20 children with atopic dermatitis, using a smartwatch installed with the application Itch Tracker. Depth of sleep was analysed using polysomnography. The severity of atopic dermatitis was scored using Eczema Area and Severity Index (EASI) and Patient-Oriented Eczema Measure (POEM). The number and time of nocturnal scratching measured by Itch Tracker had a significantly positive correlation with EASI scores, whereas POEM scores were not correlated with EASI scores. Mean sleep efficiency was 90.0% and scratching episodes (n = 67) started mainly during the awake stage or light sleep stages. In the scratching episodes that started during sleep stages (n = 34), the sleep stage changed to a lighter one or to the awake stage in 35.5% of episodes. Itch Tracker is applicable to measure nocturnal scratching in children. Nocturnal scratching can deteriorate quality of sleep by changing the sleep stage to a lighter one or to the awake stage.

Monitoring Sleep and Scratch Improves Quality of Life in Patients with Atopic Dermatitis

Atopic dermatitis itch may cause sleep disturbance and impair quality of life. For patients finding topical therapy difficult to continue, it is important to control itch and reduce scratching. This study developed algorithms to measure nocturnal sleep and scratch, using an actigraph device worn on the back of the hand, and assessed smartphone application feedback to improve adherence with therapy. In the first trial, actigraph measurements in 5 participants who wore the device were highly correlated with measurements by a sleep-monitoring device beneath the mattress. Total actigraph-measured scratching duration for each hour of sleep was highly correlated with measurements by a person rating infrared video-recording of the sleepers. In the second trial, 40 patients with atopic dermatitis were randomly allocated into an intervention group that used the actigraph and smartphone application, and a control group that did not. Both groups were instructed to use the same moisturizer. Dermatology Life Quality Index scores decreased significantly from baseline and were lower than those in the control group at week 8. It is suggested that the device and associated smartphone application reinforced therapy adherence, moisturizer use, and contributed to improved quality of life in patients with atopic dermatitis.

Defining digital measurement of scratching during sleep, or “Nocturnal Scratch”: A review of the literature (Preprint)

BACKGROUND

Digital sensing solutions represent a convenient, objective, relatively inexpensive method that could be leveraged for assessing symptoms of various health conditions. Recent progress in the capabilities of digital sensing products has targeted the measurement of scratching during sleep, traditionally referred to as nocturnal scratching, in patients with atopic dermatitis or other skin conditions. Many solutions measuring nocturnal scratch have been developed; however, a lack of efforts toward standardization of the measure's definition and contextualization of scratching during sleep hampers the ability to compare different technologies for this purpose.

OBJECTIVE

We aimed to address this gap and bring forth unified measurement definitions for nocturnal scratch.

METHODS

We performed a narrative literature review of definitions of scratching in patients with skin inflammation and a targeted literature review of sleep in the context of the period during which such scratching occurred. Both searches were limited to English language studies in humans. The extracted data were synthesized into themes based on study characteristics: scratch as a behavior, other characterization of the scratching movement, and measurement parameters for both scratch and sleep. We then developed ontologies for the digital measurement of sleep scratching.

RESULTS

In all, 29 studies defined inflammation-related scratching between 1996 and 2021. When cross-referenced with the results of search terms describing the sleep period, only 2 of these scratch-related papers also described sleep-related variables. From these search results, we developed an evidence-based and patient-centric definition of nocturnal scratch: an action of rhythmic and repetitive skin contact movement performed during a delimited time period of intended and actual sleep that is not restricted to any specific time of the day or night. Based on the measurement properties identified in the searches, we developed ontologies of relevant concepts that can be used as a starting point to develop standardized outcome measures of scratching during sleep in patients with inflammatory skin conditions.

CONCLUSIONS

This work is intended to serve as a foundation for the future development of unified and well-described digital health technologies measuring nocturnal scratching and should enable better communication and sharing of results between various stakeholders taking part in research in atopic dermatitis and other inflammatory skin conditions.

Which objective itch-assessment tools are applicable to patients with advanced cognitive impairments? A scoping review

BACKGROUND

Itching is an irritating and uncomfortable sensation that has a profound effect on patients' physical and mental health. It is a major under-recognised problem in older patients who cannot express their pain due to advanced cognitive impairment. Therefore, objective itch-assessment tools that do not rely on patients' reports of itching may be of value for this patient group.

OBJECTIVE

To summarise the characteristics of validated objective itch-assessment tools for patients with advanced cognitive impairment.

METHODS

This scoping review was conducted according to the PRISMA extension for scoping reviews checklist. The PubMed, CINAHL and Cochrane Library databases were searched, via database-specific search strategies, for articles published in English between January 1, 1990 and March 11, 2020. Based on the eligibility criteria, two authors independently screened the articles for inclusion. Thereafter, the lead author performed data extraction and analysis.

RESULTS

Three validated scratch-monitoring using accelerometers and a sound sensor and one validated scratch-mark assessment have been reported. The Actiwatch Plus, ActiTrac^® , body-conducted sound sensor and Scoring Atopic Dermatitis index for scratching (SCORAD-scratch) had positive criterion validity outcomes. The Actiwatch Plus, ActiTrac^® and body-conducted sound sensor were significantly correlated with scratch behaviour (r = 0.91, p < 0.001; r = 0.71, p = 0.042; r = 0.99, and p-value not shown, respectively). The SCORAD-scratch was significantly correlated with subjective itch-assessment scores (r = 0.78-0.80, p = <0.0001-0.010).

CONCLUSIONS

This scoping review summarises the characteristics of validated objective itch-assessment tools to investigate which of these are applicable to older patients with advanced cognitive impairments. Although there are limitations and further verification is required, the ActiTrac^® , Actiwatch Plus and body-conducted sound sensor may be useful for measuring scratch movements and itching.

IMPLICATIONS FOR PRACTICE

Nurses and patients' families may better understand the characteristics and validity of each objective itch-assessment tool and select the optimal tool for patients with advanced cognitive impairment who cannot express their discomfort caused due to itching.

Use of technology for the objective evaluation of scratching behavior: A systematic review

Introduction

Pruritus is a common symptom across various dermatologic conditions, with a negative impact on quality of life. Devices to quantify itch objectively primarily use scratch as a proxy. This review compares and evaluates the performance of technologies aimed at objectively measuring scratch behavior.

Methods

Articles identified from literature searches performed in October 2020 were reviewed and those that did not report a primary statistical performance measure (eg, sensitivity, specificity) were excluded. The articles were independently reviewed by 2 authors.

Results

The literature search resulted in 6231 articles, of which 24 met eligibility criteria. Studies were categorized by technology, with actigraphy being the most studied (n = 21). Wrist actigraphy's performance is poorer in pruritic patients and inherently limited in finger-dominant scratch detection. It has moderate correlations with objective measures (Eczema and Area Severity Index/Investigator's Global Assessment: r_s(ρ) = 0.70-0.76), but correlations with subjective measures are poor (r² = 0.06, r_s(ρ) = 0.18-0.40 for itch measured using a visual analog scale). This may be due to varied subjective perception of itch or actigraphy's underestimation of scratch.

Conclusion

Actigraphy's large variability in performance and limited understanding of its specificity for scratch merits larger studies looking at validation of data analysis algorithms and device performance, particularly within target patient populations.

Nocturnal pruritus and sleep disturbance associated with dermatologic disorders in adult patients

Nocturnal pruritus (NP) is a relatively common reason for dermatologic consultation. Its pathophysiology is partially understood. Skin conditions such as atopic dermatitis, psoriasis, urticaria, and prurigo nodularis are well-described causes of NP. The most distressing sequela of NP is sleep deficit, which can lead to physical and mental disturbances (e.g., daytime somnolence and fatigue) and negative emotional states that profoundly affect quality of life. However, this aspect of NP is often overlooked by dermatologists. It is essential to assess sleep quality in such patients and adopt appropriate measures to arrest the problem at an early stage. We conducted an evidence-based literature review to highlight the pathogenetic mechanisms of NP, identify dermatologic etiologies, and explore methods that have been used to assess the quality of sleep. Furthermore, we performed a systematic review of studies on sleep disturbance relevant to NP in patients with dermatologic conditions. Finally, we discuss the evidence on treatment options for NP and indicate therapies that may target both NP and sleep disturbance.

Sleep Disturbances and Atopic Dermatitis: Relationships, Methods for Assessment, and Therapies

Atopic dermatitis is one of the most common chronic inflammatory skin conditions and is associated with sleep disturbances in 47% to 80% of children and 33% to 90% of adults. Herein, we review the literature on sleep disturbances experienced by patients with atopic dermatitis, as well as the mechanisms that may underlie this. We present subjective and objective methods for measuring sleep quantity and quality and discuss strategies for management. Unfortunately, the literature on this topic remains sparse, with most studies evaluating sleep as a secondary outcome using subjective measures. The development of portable, at-home methods for more objective measures offers new opportunities to better evaluate sleep disturbances in atopic dermatitis research studies and in clinical practice.

Machine Learning in Dermatology: Current Applications, Opportunities, and Limitations

Machine learning (ML) has the potential to improve the dermatologist's practice from diagnosis to personalized treatment. Recent advancements in access to large datasets (e.g., electronic medical records, image databases, omics), faster computing, and cheaper data storage have encouraged the development of ML algorithms with human-like intelligence in dermatology. This article is an overview of the basics of ML, current applications of ML, and potential limitations and considerations for further development of ML. We have identified five current areas of applications for ML in dermatology: (1) disease classification using clinical images; (2) disease classification using dermatopathology images; (3) assessment of skin diseases using mobile applications and personal monitoring devices; (4) facilitating large-scale epidemiology research; and (5) precision medicine. The purpose of this review is to provide a guide for dermatologists to help demystify the fundamentals of ML and its wide range of applications in order to better evaluate its potential opportunities and challenges.

Emerging Methods to Objectively Assess Pruritus in Atopic Dermatitis

INTRODUCTION

Atopic dermatitis (AD) is an inflammatory skin disease with a chronic, relapsing course. Clinical features of AD vary by age, duration, and severity but can include papules, vesicles, erythema, exudate, xerosis, scaling, and lichenification. However, the most defining and universal symptom of AD is pruritus. Pruritus or itch, defined as an unpleasant urge to scratch, is problematic for many reasons, particularly its negative impact on quality of life. Despite the profoundly negative impact of pruritus on patients with AD, clinicians and researchers lack standardized and validated methods to objectively measure pruritus. The purpose of this review is to discuss emerging methods to assess pruritus in AD by describing objective patient-centered tools developed or enhanced over the last decade that can be utilized by clinicians and researchers alike.

METHODS

This review is based on a literature search in Medline, Embase, and Web of Science databases. The search was performed in February 2019. The keywords were used "pruritus," "itch," "atopic dermatitis," "eczema," "measurements," "tools," "instruments," "accelerometer," "wrist actigraphy," "smartwatch," "transducer," "vibration," "brain mapping," "magnetic resonance imaging," and "positron emission tomography." Only articles written in English were included, and no restrictions were set on study type. To focus on emerging methods, prioritization was given to results from the last decade (2009-2019).

RESULTS

The search yielded 49 results in PubMed, 134 results in Embase, and 85 results in Web of Science. Each result was independently reviewed in a standardized manner by two of the authors (M.S., K.L.), and disagreements between reviewers were resolved by consensus. Relevant findings were categorized into the following sections: video surveillance, acoustic surveillance, wrist actigraphy, smart devices, vibration transducers, and neurological imaging. Examples are provided along with descriptions of how each technology works, instances of use in research or clinical practice, and as applicable, reports of validation studies and correlation with other methods.

CONCLUSION

The variety of new and improved methods to evaluate pruritus in AD is welcomed by clinicians, researchers, and patients alike. Future directions include next-generation smart devices as well as exploring new territories, such as identifying biomarkers that correlate to itch and machine-learning programs to identify itch processing in the brain. As these efforts continue, it will be essential to remain patient-centered by developing techniques that minimize discomfort, respect privacy, and provide accurate data that can be used to better manage itch in AD.

Brain allopregnanolone induces marked scratching behaviour in diet-induced atopic dermatitis mouse model

Allopregnanolone (ALLO) is a neurosteroid produced in the brain, but so far, no study has explored its link with itching. Herein, we used a diet-induced atopic dermatitis mouse model to examine whether exogenously administered and endogenously produced ALLO contribute to inducing scratching. Systemic administration of ALLO elicited robust scratching in the atopic dermatitis model, while it did not affect spontaneous and pruritogen-induced scratching in normal mice. ALLO caused scratching when administered intracisternally, but not when administered intrathecally or intradermally, suggesting the involvement of supraspinal mechanisms. Pharmacological analyses suggested that both γ-aminobutyric acid type A receptor activation and serotonin type 3 receptor inhibition were involved in ALLO-induced scratching. We next examined whether endogenously produced ALLO is involved in ethanol-induced scratching in atopic dermatitis mice, because ethanol administration increases ALLO in rodent brain. Acute ethanol administration increased brain ALLO levels, which coincided with increased scratching. Pre-treatment with finasteride, a synthetic ALLO inhibitor, suppressed ethanol-induced scratching and ALLO production in the brain. Collectively, our results demonstrated for the first time that ALLO administration caused marked scratching in atopic dermatitis mice, and ethanol-induced scratching may be mediated through endogenously produced brain ALLO.

Actigraphy-measured nocturnal wrist movements and assessment of sleep quality in patients with bullous pemphigoid: a pilot case-control study

BACKGROUND

Bullous pemphigoid (BP) is a distressing autoimmune bullous disease strongly associated with severe pruritus; however, data concerning pruritus in BP are still scarce. No clinical research evaluating the effect of BP on sleep quality has been conducted.

AIM

To evaluate the intensity of pruritus measured by nocturnal wrist movements (NWMs) and the sleep quality in patients with BP using actigraphy in comparison with nonpruritic healthy controls (HCs) with subsequent correlations with an itch visual analogue scale (VAS) as a subjective measure, disease severity [Bullous Pemphigoid Disease Area Index (BPDAI), urticaria/erythema, erosions/blisters] and serum total IgE level.

METHODS

In total, 31 patients with newly diagnosed BP (mean ± SD age 75.4 ± 12.3 years) and 40 nonpruritic HCs (age 73.5 ± 11.7 years) were recruited. All participants wore a sleep monitor (ActiSleep+) on the dominant wrist.

RESULTS

For patients with BP, median VAS score was 5.5 and median BPDAI was 43 (urticaria/erythema BPDAI was 16, erosions/blisters BPDAI was 29). Scratching, defined as bouts of NWMs, was significantly (P < 0.001) more intensive in patients with BP than in controls. Characteristic of BP was that scratching bouts corresponded with the slowest wrist movements. There were no correlations with VAS, BPDAI or total IgE level. Compared with HCs, patients with BP presented significant (P < 0.001) sleep disturbances, as determined by sleep efficiency, waking after sleep onset and average duration of awakening, and these were strongly correlated with urticaria/erythema BPDAI.

CONCLUSION

Nocturnal wrist movements measured by actigraphy are more intensive in patients with BP than in nonpruritic HCs, and characteristically slow movements. Actigraphy method showed very low sleep quality in patients with BP, thus severity of BP has a negative impact on sleep.

Barbiturates enhance itch-associated scratching in atopic dermatitis mice: A possible clue to understanding nocturnal pruritus in atopic dermatitis

In chronic pruritic diseases such as atopic dermatitis, pruritus is exacerbated during nocturnal sleep; however, the underlying mechanism remains unclear. We previously demonstrated that acute administration of the sedative-hypnotics ethanol markedly enhanced itch-associated spontaneous scratching in a diet-induced mouse model of atopic dermatitis. In the present study, to expand our previous finding and provide a general mechanism for the central modulation of chronic itch, we examined whether other hypnotic drugs, such as barbiturates and benzodiazepines, also enhance scratching, and further investigated the underlying mechanism. Barbiturates markedly enhanced spontaneous scratching in the atopic dermatitis model but not controls. However, unexpectedly, benzodiazepines only slightly increased scratching, and the selective γ-aminobutyric acid type A (GABA_A) receptor agonist, muscimol, had no effect. Local injection studies have demonstrated that barbiturates act at the supraspinal level to enhance scratching. Barbiturate-induced scratching was inhibited not only by GABA_A receptor antagonists but also by an L-type voltage-dependent calcium channel (L-VDCC) agonist and an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) glutamate receptor agonist. An intracisternally injected AMPA receptor antagonist alone or in combination with an L-VDCC antagonist sufficiently enhanced scratching. Barbiturate-induced scratching enhancement was observed in another atopic dermatitis model, NC/Nga, but not in histamine-induced acute itch model in normal healthy mice. Overall, our results suggest that a synergistic effect among AMPA receptor inhibition, GABA_A receptor activation, and L-VDCC inhibition in the brain mediates barbiturate-induced scratching in atopic dermatitis mice. This observation may provide a novel clue to understanding a supraspinal itch mechanism in chronic diseases such as atopic dermatitis.

Monitoring of atopic dermatitis using leaky coaxial cable

In our daily life, inadvertent scratching may increase the severity of skin diseases (such as atopic dermatitis etc.). However, people rarely pay attention to this matter, so the known measurement behaviour of the movement is also very little. Nevertheless, the behaviour and frequency of scratching represent the degree of itching, and the analysis of scratching frequency is helpful to the doctor's clinical dosage. In this Letter, a novel system is proposed to monitor the scratching motion of a sleeping human body at night. The core device of the system is just a leaky coaxial cable (LCX) and a router. Commonly, LCX is used in the blind field or semi-blindfield in wireless communication. The new idea is that the leaky cable is placed on the bed, and then the state information of physical layer of wireless communication channels is acquired to identify the scratching motion and other small body movements in the human sleep process. The results show that it can be used to detect the movement and its duration. Channel state information (CSI) packet is collected by card installed in the computer based on the 802.11n protocol. The characterisation of the scratch motion in the collected CSI is unique, so it can be distinguished from the wireless channel amplitude variation trend.

Frequency and Management of Sleep Disturbance in Adults with Atopic Dermatitis: A Systematic Review

Introduction

Intense nocturnal pruritus as well as the complex pathophysiology of atopic dermatitis (AD) can severely affect sleep and become a major factor in negatively impacting quality of life in adults. However, much of the literature on sleep disturbance in AD patients is on the pediatric population, and it is not well studied in adults. Furthermore, limited studies are available to guide effective management of sleep disturbance in AD in general. We review the literature to present the studies that have investigated the relationship between AD and its effect on sleep in adults and provide an approach for clinicians caring for this population.

Methods

A systematic literature search was conducted through the PubMed and EMBASE databases using the search terms “atopic dermatitis” OR “eczema” AND “sleep.” The articles generated by the search and their references were reviewed.

Results

A high prevalence of sleep disturbance is experienced by adults with AD. The likelihood of sleep disturbance is much higher in patients with AD compared to those without AD. Sleep disturbance appears to worsen with AD severity. Pruritus and scratching appear to be large contributors to sleep disturbance in adult patients with AD.

Conclusion

It is important that clinicians evaluate the severity of AD and ask general questions about itching, sleep, impact on daily activities, and persistence of disease during each patient visit and follow-up with the complaint of sleep disturbance. Management of sleep disturbance in AD should focus on adequate disease control of AD as well as possible medical interventions to help improve sleep. The pathophysiology of sleep disturbance in AD is extremely complex, and further research is needed to better understand the interplay of the immune system, circadian rhythm, and environmental factors implicated in both AD and sleep.

Detection of Nocturnal Scratching Movements in Patients with Atopic Dermatitis Using Accelerometers and Recurrent Neural Networks

Atopic dermatitis is a chronic inflammatory skin condition affecting both children and adults and is associated with pruritus. A method for objectively quantifying nocturnal scratching events could aid in the development of therapies for atopic dermatitis and other pruritic disorders. High-resolution wrist actigraphy (three-dimensional accelerometer sensors sampled at 20 Hz) is a noninvasive method to record movement. This paper presents an algorithm to detect nocturnal scratching events based on actigraphy data. The twofold process consists of segmenting the data into "no motion," "single handed motion," and "both handed motion" followed by discriminating motion segments into scratching and other motion using a bidirectional recurrent neural network classifier. The performance was compared against manually scored infrared video data collected from 24 subjects (6 healthy controls and 18 atopic dermatitis patients) demonstrating an score of 0.68 and a rank correlation of 0.945. The algorithm clearly outperformed a published reference method based on wrist actigraphy ( score of 0.09 and a rank correlation of 0.466). The results suggest that scratching movements can be discriminated from other nocturnal movements accurately.

Thermoregulation, scratch, itch and sleep deficits in children with eczema

Successful sleep onset and maintenance is associated with a reduction in core temperature, facilitated by heat loss at the distal periphery. Problems with initiating and maintaining sleep in children with eczema may relate to impaired thermoregulatory mechanisms, which also contribute to itching and scratching. Our hypothesis was that nocturnal distal skin temperature in eczematous children would be lower than controls, and would also be related to poor sleep quality. We compared overnight polysomnography and distal (finger) and proximal (clavicle) skin temperature in 18 children with eczema and 15 controls (6-16 years). Children with eczema had longer periods of nocturnal wakefulness (mean [SD] = 88.8 [25.8] vs. 44.3 [35.6] min) and lower distal temperatures (34.1 [0.6] °C vs. 34.7 [0.4] °C) than controls, whereas proximal temperature and the distal-proximal gradient were not significantly different. In children with eczema, a higher distal temperature was associated with indicators of poor sleep quality, whereas lower distal temperature was related to more scratching events during sleep. In conclusion, our findings indicate complex interrelationships among eczema, thermoregulation and sleep, and further, that deficits in thermoregulatory mechanisms may contribute to sleep disturbances in children with eczema.

Mechanism of Sleep Disturbance in Children with Atopic Dermatitis and the Role of the Circadian Rhythm and Melatonin

Sleep disturbance is common in children with atopic dermatitis (AD). It is a major factor leading to impaired quality of life in these patients and could have negative effects on neurocognitive function and behavior. However, the pathophysiology of sleep disturbance in children with AD is poorly understood, and there is no consensus on how to manage sleep problems in these patients. Pruritus and scratching could lead to sleep disruption but is unlikely the sole etiology. The circadian rhythm of cytokines, the immune system, and skin physiology such as transcutaneous water loss and skin blood flow might also play a role. Recent studies have suggested that melatonin could also be involved due to its multiple effects on sleep, immunomodulation, and anti-oxidant ability. Environmental factors should also be considered. In this review, we summarize the current understanding of the pathophysiology of sleep disturbance in children with AD, and discuss possible therapeutic implications.

Assessment of pruritus in patients with psoriasis and atopic dermatitis: subjective and objective tools

Pruritus is a major symptom of skin disease. The quest to identify a valid and reliable method to assess this important symptom has led to the development of a myriad of measurement tools. Some clinical trials using subjective measurements of itch intensity have reported itch intensity levels in psoriasis that are close to severity levels found in atopic dermatitis. Although it is possible that we have previously underestimated the severity of pruritus in psoriasis, these unexpected findings prompted us to review and evaluate these subjective methodologies. We provide an overview of the current tools available to measure itch severity, including subjective rating scales and questionnaires and objective measures of scratch activity through videotape observation and wrist actigraphy. We discuss the advantages and limitations of these methods and encourage consideration of a novel objective method of evaluation.

Diurnal and twenty-four hour patterning of human diseases: acute and chronic common and uncommon medical conditions

The symptom intensity and mortality of human diseases, conditions, and syndromes exhibit diurnal or 24 h patterning, e.g., skin: atopic dermatitis, urticaria, psoriasis, and palmar hyperhidrosis; gastrointestinal: esophageal reflux, peptic ulcer (including perforation and hemorrhage), cyclic vomiting syndrome, biliary colic, hepatic variceal hemorrhage, and proctalgia fugax; infection: susceptibility, fever, and mortality; neural: frontal, parietal, temporal, and occipital lobe seizures, Parkinson's and Alzheimer's disease, hereditary progressive dystonia, and pain (cancer, post-surgical, diabetic neuropathic and foot ulcer, tooth caries, burning mouth and temporomandibular syndromes, fibromyalgia, sciatica, intervertebral vacuum phenomenon, multiple sclerosis muscle spasm, and migraine, tension, cluster, hypnic, and paroxysmal hemicranial headache); renal: colic and nocturnal enuresis and polyuria; ocular: bulbar conjunctival redness, keratoconjunctivitis sicca, intraocular pressure and anterior ischemic optic neuropathy, and recurrent corneal erosion syndrome; psychiatric/behavioral: major and seasonal affective depressive disorders, bipolar disorder, parasuicide and suicide, dementia-associated agitation, and addictive alcohol, tobacco, and heroin cravings and withdrawal phenomena; plus autoimmune and musculoskeletal: rheumatoid arthritis, osteoarthritis, axial spondylarthritis, gout, Sjögren's syndrome, and systemic lupus erythematosus. Knowledge of these and other 24 h patterns of human pathophysiology informs research of their underlying circadian and other endogenous mechanisms, external temporal triggers, and more effective patient care entailing clinical chronopreventive and chronotherapeutic strategies.

The excimer lamp induces cutaneous nerve degeneration and reduces scratching in a dry-skin mouse model

Epidermal hyperinnervation, which is thought to underlie intractable pruritus, has been observed in patients with atopic dermatitis (AD). The epidermal expression of axonal guidance molecules has been reported to regulate epidermal hyperinnervation. Previously, we showed that the excimer lamp has antihyperinnervative effects in nonpruritic dry-skin model mice, although epidermal expression of axonal guidance molecules was unchanged. Therefore, we investigated the antipruritic effects of excimer lamp irradiation and its mechanism of action. A single irradiation of AD model mice significantly inhibited itch-related behavior 1 day later, following improvement in the dermatitis score. In addition, irradiation of nerve fibers formed by cultured dorsal root ganglion neurons increased bleb formation and decreased nerve fiber expression of nicotinamide mononucleotide adenylyl transferase 2, suggesting degenerative changes in these fibers. We also analyzed whether attaching a cutoff excimer filter (COF) to the lamp, thus decreasing cytotoxic wavelengths, altered hyperinnervation and the production of cyclobutane pyrimidine dimer (CPD), a DNA damage marker, in dry-skin model mice. Irradiation with COF decreased CPD production in keratinocytes, as well as having an antihyperinnervative effect, indicating that the antipruritic effects of excimer lamp irradiation with COF are due to induction of epidermal nerve degeneration and reduced DNA damage.

Novel acoustic evaluation system for scratching behavior in itching dermatitis: rapid and accurate analysis for nocturnal scratching of atopic dermatitis patients

Quantitative analysis of itching in patients with itching dermatitis including atopic dermatitis (AD) is indispensable for the evaluation of disease activity and response to therapy. However, the objective evaluation system for itching is limited. We have developed a new objective and quantitative scratching behavior detection system using a wristwatch-type sound detector. The scratch sound detected on the wrist is recorded on a personal computer through a filtering, squaring and smoothing process by specific hardware. Subsequently, the data is automatically processed and judged for the scratching movement using specific software based on the periodicity and energy of the signal. Twenty-four measurements for healthy volunteers and those with AD by this system were evaluated by comparison with a simultaneously recorded video analysis system. The ratio of scratching time in sleeping time evaluated by these two systems was almost identical. The healthy subjects scratched their skin approximately 2 min during 6 h of sleeping time, while the mean scratching time of AD subjects was 24 min in their sleeping time. In contrast to the time-consuming video analysis system, this system takes only several minutes for evaluation of an overnight record. This scratch sound detection system is expected to serve as a new objective evaluation tool for itching dermatitis, namely, AD, and development of anti-itch therapies for dermatitis.

A study of serum concentrations and dermal levels of NGF in atopic dermatitis and healthy subjects

Nerve growth factor (NGF) was reported to be increased in the serum and skin of atopic dermatitis (AD) patients, to the extent that serum nerve growth factor levels were proposed to serve as a marker of disease severity. We studied NGF levels in the serum and dermis using skin microdialysis and attempted to correlate them with disease severity. We also examined if potential differences between morning and evening levels of NGF can explain the phenomenon of nocturnal itch. In addition, neurogenic inflammation and itch were induced using histamine iontophoresis in lesional and non-lesional skin and the effect of experimental itch on dermal NGF concentration was examined. We found that systemic (serum) and eczematous skin levels of NGF in AD are significantly lower in comparison to healthy controls. Serum NGF decreases from morning to late afternoon in both groups. Interestingly, serum NGF levels were correlated to disease severity in the morning in AD, although the NGF concentration in AD were significantly lower than in the healthy group. The local itch and neurogenic inflammation induction via experimental histamine reduced local NGF levels in the eczema and non-lesional skin in atopics, but not in the healthy controls, where it was slightly increased. The higher the clinical severity of the eczema, a significantly less pronounced effect of neurogenic inflammation on the local levels of NGF was found. The availability of measurable NGF might be reduced by a higher expression of NGF receptors. The fluctuations of NGF levels during the day suggest a complex modulation of this neurotrophin, potentially linked to stress or to an altered neurophysiological mechanism.

Enhanced responses of lumbar superficial dorsal horn neurons to intradermal PAR-2 agonist but not histamine in a mouse hindpaw dry skin itch model

Chronic itch is symptomatic of many skin conditions and systemic diseases. Little is known about pathophysiological alterations in itch-signaling neural pathways associated with chronic itch. We used a mouse model of hindpaw chronic dry skin itch to investigate properties of presumptive itch-signaling neurons. Neurons in the lumbar superficial dorsal horn ipsilateral to hindpaw dry skin treatment exhibited a high level of spontaneous activity that was inhibited by scratching the plantar surface. Most spontaneously active units exhibited further increases in firing rate following intradermal injection of an agonist of the protease-activated receptor PAR-2, or histamine. The large majority of pruritogen-responsive units also responded to capsaicin and allyl isothiocyanate. For neurons ipsilateral to dry skin treatment, responses elicited by the PAR-2 agonist, but not histamine or mechanical stimuli, were significantly larger compared with neurons ipsilateral to vehicle (water) treatment or neurons recorded in naïve (untreated) mice. The spontaneous activity may signal ongoing itch, while enhanced PAR-2 agonist-evoked responses may underlie hyperknesis (enhanced itch), both of which are symptomatic of many chronic itch conditions. The enhancement of neuronal responses evoked by the PAR-2 agonist, but not by histamine or mechanical stimuli, implies that the dry skin condition selectively sensitized PAR-2 agonist-sensitive primary afferent pruriceptors.

Ethanol aggravates itch-related scratching in hairless mice developing atopic dermatitis

In patients with atopic dermatitis, alcoholic beverages can sometimes trigger or enhance itching. We have previously reported that HR-1 hairless mice fed a commercial special diet, HR-AD, but not a normal diet, develop atopic dermatitis-like skin inflammation with prolonged spontaneous scratching, and that skin barrier dysfunction is involved in the basal scratching. In the present study, the effects of ethanol on itch-related scratching were examined in this mouse model. When ethanol (30%, 10 ml/kg) was given orally to HR-AD-fed mice, scratching with long duration was further markedly increased, while oral ethanol administration had little effect on the scratching response in normal diet-fed mice. The scratching response after oral ethanol administration in HR-AD-fed mice (ethanol-induced scratching) was attenuated by antagonism of the mu-opioid receptor or local skin anesthesia, as in human itching. Ethanol-induced scratching was also suppressed by improvement of skin barrier function by an application of petrolatum ointment, while ethanol administration itself did not affect the function. This suggests that ethanol indirectly aggravates the basal scratching. Although antagonism of the transient receptor potential vanilloid-1 did not affect ethanol-induced scratching, blockade of ethanol actions in the central nervous system (CNS), including gamma-aminobutyric acid type A receptor antagonism and N-methyl-d-aspartate receptor activation, inhibited it. Taken together, the present study demonstrates that orally administered ethanol markedly aggravates itch-related scratching in HR-AD-fed mice developing atopic dermatitis, and suggests that the CNS depressant actions of ethanol play an important role in the aggravation.

A novel acoustic evaluation system of scratching in mouse dermatitis: rapid and specific detection of invisibly rapid scratch in an atopic dermatitis model mouse

Scratching is an essential and a skin specific behavior induced by itching, which is a common symptom of atopic dermatitis (AD) and other types of dermatitis. Itching sensation and scratching are closely associated and thus scratching times are currently used for evaluating itching in animal models. However, objective measuring systems of scratching to assess the grade of dermatitis and the effectiveness of anti-pruritic drugs in animal dermatitis models are lacking. To investigate a quantitative evaluation system for itching, we have developed a novel acoustic scratching counting system and compared its accuracy with time-consuming slow-motion video recording system. We have also objectively evaluated the efficacy of an antihistamine using this novel system. Scratching behavior of an AD model mouse (K14 driven IL-18 transgenic mouse) was recorded visually and acoustically. Specific scratching sound produced by mice was recorded and counted using a software we have developed, and the results obtained using our acoustic system were not statistically different from data obtained using slow motion video system. Surprisingly, mice scratched more than 10 times/second, which was invisibly rapid motion and revealed inaccuracy of conventional hand counting system. Results were identical to that of measured by 10 times time costing slow-motion video analysis. The antihistamine is clearly effective for suppression of scratching as demonstrated using this objective and accurate method. This novel motion analysis system will open a window for physiological and pathological analysis for animal models and development of anti-pruritic drugs.

Lesson from performing SCORADs in children with atopic dermatitis: Subjective symptoms do not correlate well with disease extent or intensity

BACKGROUND

Atopic dermatitis (AD) is a distressing disease associated with pruritus and sleep disturbance. It is not known how well these symptoms correlate with the extent and intensity of eczematous involvement. We evaluated whether: (i) the level of sleep loss correlates with pruritus and (ii) the level of pruritus correlates with the extent or severity of AD in children according to the SCORing Atopic Dermatitis (SCORAD) index.

METHOD

Patients with AD younger than 18 years old were recruited from the pediatric dermatology clinic of a university teaching hospital, and AD severity was evaluated by the SCORAD index.

RESULTS

One hundred and eighty-two Chinese children with AD (107 boys and 75 girls) [mean (SD) age of 9.6 (4.2) years] were recruited. Their mean (SD) overall SCORAD was 30.1 (19.2). Sleep loss was strongly correlated with pruritus (r = 0.57, P < 0.001). However, the two subjective symptoms were only weakly correlated with the objective signs (extent and intensity) of AD. The correlations between pruritus and extent and intensity were 0.42 (P < 0.001) and 0.38 (P < 0.001), respectively, and the correlations between sleep loss and extent and intensity were 0.38 (P < 0.001) and 0.34 (P < 0.001), respectively.

CONCLUSION

We speculate that the lack of a better correlation was either because pruritus and sleep loss as reported by parents were imprecise, or that mechanisms other than disease extent or severity are responsible for the pathogenesis of these subjective symptoms.

Nocturnal wrist movements are correlated with objective clinical scores and plasma chemokine levels in children with atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is a distressing disease associated with pruritus and sleep disturbance. Scratching due to pruritus is an important mechanism in the exacerbation of AD but is difficult to document in the home environment.

OBJECTIVES

To evaluate whether nocturnal wrist activities, defined as average acceleration in the early hours of sleep, were correlated with components of the SCORing Atopic Dermatitis (SCORAD) index and various AD-associated chemokine markers.

METHODS

Patients with AD aged under 18 years were recruited and the severity of eczema was assessed with the SCORAD index. Concentrations of plasma AD-associated chemokines [cutaneous T-cell attracting cytokine (CTACK); macrophage-derived chemokine (MDC); thymus and activation regulated chemokine (TARC)], interleukin (IL)-18, serum total IgE, and eosinophil counts were measured in these patients. Healthy children with noninflammatory and nonitchy skin conditions as well as healthy children of staff volunteers were recruited as controls. All children were instructed to wear the DigiTrac monitor on their dominant wrist before sleeping. The monitor was programmed to record limb motion between 22.00 and 08.00 h the following morning.

RESULTS

Twenty-four Chinese children with AD (mean +/- SD age 12.6 +/- 3.7 years) and 15 normal children (mean +/- SD age 11.9 +/- 3.4 years) were recruited. The median (interquartile range) SCORAD was 54.8 (32.8-70.2). Plasma concentrations in pg mL(-1) of CTACK, MDC, TARC and IL-18 in the patients were 105 (92-172), 1648 (973-4214), 258 (100-850) and 415 (304-539), respectively. When compared with controls, most wrist activities occurred at frequencies between 1 and 3 Hz. These activities were most consistent over the first 3 h of sleeping and correlated significantly with disease severity, extent, intensity, and AD-associated chemokine markers CTACK, MDC and TARC. However, there was no significant correlation between wrist activities and the subjective symptom of pruritus or sleep loss.

CONCLUSIONS

This is the first study to demonstrate that wrist activities, nonintrusively measured by the DigiTrac monitor at home, are closely correlated with the objective clinical scores and levels of peripheral blood chemokine markers for AD but not with the reported symptoms of pruritus or sleep loss. We propose that wrist activities between 1 and 3 Hz for the first 3 h are a good indicator of AD severity in children and should substitute for the pruritus and sleep-loss components of the SCORAD.

Measurement of itch using actigraphy in pediatric and adult populations

We have studied nocturnal movements using wrist-worn accelerometers in 33 adults with a range of pruritic dermatoses, 30 adult control subjects, 25 children with atopic dermatitis, and 17 pediatric control subjects. In all, 26 adults and 20 children were studied on more than one occasion, up to a maximum of 6 occasions. Participants were examined and a range of subjective measures about the extent of skin disease, itch, and quality of sleep were recorded. We show clear differences between patients and control subjects for both age groups studied, with activity medians approximately twice as high in the patients as in the control subjects ( P < .001). Studies on the same person show a considerable night-to-night variation that is unlikely to relate to measurement error, but instead, we believe, reflect genuine differences in nocturnal activity (and perhaps disease severity). Movement through the night did not seem to follow any obvious pattern. The relation between subjective measures, Severity sCORing of Atopic Dermatitis (SCORAD) index scores, and objective recorded activity was imperfect, with much unaccounted for variation. In particular, in adults, but not in children, we found a negative correlation (-0.44, P < .02) between objective movement activity and self-reported quality of sleep. Our results support the use of objective measures of scratch in the assessment of disease activity, and suggest that the relation between subjective and objective measures of disease severity may not be straightforward.

A new analytical system for quantification scratching behaviour in mice

BACKGROUND

Scratching behaviour is an important component of human atopic dermatitis. The duration of scratching determines the extent of skin damage and thus the rash, but quantification of this is difficult. Establishment of a method for measuring the duration of scratching is important in order to make objective assessments of the factors that may cause the itch and also the efficacy of new antipruritic drugs.

OBJECTIVES

A novel method for assessing the duration of scratching in mice was evaluated, based on the time course changes in the distance between the animal's hind limbs and the back of the neck during scratching behaviour.

METHODS

Compound 48/80 was administered intradermally to the back of ICR mice and their scratching behaviour was recorded on digital videotape. The distance between the back and the hind limb was measured continuously using an image analysis system.

RESULTS

Measurement of the frequency and duration when the mouse's hind limb came into contact with the back of the neck provided an accurate method of quantitating scratching behaviour.

CONCLUSIONS

This system provides a new method of quantifying scratching behaviour in a mouse.

The development of an objective method for measuring scratch in children with atopic dermatitis suitable for clinical use

Itch is a major symptom of skin disease and remains poorly studied. We have used limb-worn digital accelerometers, and infrared video of patients as a gold standard, on children with atopic dermatitis and control subjects in their own homes at night. Video analysis shows that nocturnal scratching and restlessness are more complex than we first thought, with many movements that potentially damage the skin not conforming to stereotypical scratch movements. Children with atopic dermatitis spent a mean of 46 minutes less time motionless or sleeping at night than control subjects (468 +/- 3 [SEM] vs 422 +/- 37 [SEM], P<.001). Children with atopic dermatitis showed 2 to 3 times as much scratching or restlessness activity as control subjects, with little overlap between groups (P<.01). Scratching and restlessness were highly correlated with each other (0.94, P<.01). Accelerometer scores were highly correlated with video results (rho>0.02, P<.01, for scratching, restlessness, and sleeping time). Individual limb scores were highly correlated with each other (rho approximately 0.87-0.98), suggesting that little information would be lost if only 1 limb was measured. There was little relation between parental assessment of scratch and objective measured scratch. Accelerometers provide a useful and practical way of assessing scratching at night in the patient's own home and could be used as an objective measure of disease activity both in clinical trials and in everyday clinical practice.

Itch

Itch is a common skin sensation, with substantial effects on behaviour. Neurophysiological research has permitted accurate definition of neural pathways of itch, and has confirmed the distinctiveness of itch pathways in comparison with pain. A clinical classification of itch, based on such improved understanding, describes the difference between peripheral (pruritoceptive) and central (neurogenic or neuropathic) itch. New specific and sensitive investigational methods in people and animals enable us to better understand this bothersome symptom, and have important clinical implications. We describe the clinical classification of itch, new findings on neuropathophysiology of itch, methods for assessment, and improved treatments.

Occurrence of patchy parakeratosis in normal-appearing skin in patients with active atopic dermatitis and in patients with healed atopic dermatitis: a cause of impaired barrier function of the atopic skin

It remains unclear whether an impaired barrier function often seen in areas of normal-appearing skin in patients with active atopic dermatitis (AD) is primary event in nature or secondary to subclinical eczematous change. We then attempted to evaluate the barrier function of normal-appearing skin in both active and healed AD patients, and as well as see whether a subclinical eczematous change exists or not in the normal-appearing skin using a non-invasive method. Transepidermal water loss (TEWL) measurement and exfoliative cytology method for corneal layer were applied in 153 AD patients who have active skin lesions and 29 individuals with completely healed AD for at least 5 years and 40 normal individuals. The TEWL of normal-appearing skin in severe, moderate and mild AD cases was 10.5+/-2.9, 8.3+/-2.4 and 7.3+/-2.1 g/m2 per h, respectively. The TEWL values in severe and moderate cases were significantly higher than the normal controls (6.2+/-1.6 g/m2 per h). However, the TEWL was not deranged in patients with completely healed AD. An exfoliative cytology examination of corneal layer disclosed that patchy parakeratosis appeared in normal-appearing skin in severe, moderate and mild AD cases at a rate of 42, 29 and 19%, respectively. However, no patchy parakeratosis was recognized in patients with completely healed AD. The occurrence of patchy parakeratosis in normal-appearing skin in patients with active AD suggests that an impaired barrier function often seen in normal-appearing skin in AD patients is secondary to subclinical eczematous change in the area.

Itch characteristics in Chinese patients with atopic dermatitis using a new questionnaire for the assessment of pruritus

BACKGROUND

Although pruritus is the predominant and commonest feature of atopic dermatitis, its clinical characteristics have not been explored.

OBJECTIVE

To characterize the clinical pattern and sensory and affective dimensions of the itch experience utilizing a comprehensive itch questionnaire.

METHODS

A structured itch questionnaire based on the McGill pain questionnaire was given to 102 Chinese patients with known atopic dermatitis.

RESULTS

There were 100 patients with atopic dermatitis who fully filled the questionnaire. In 87% of the patients pruritus appeared on a daily basis. It had a prolonged duration (mean duration 10.7 7.3 years). It involved all body areas mostly in the lower limbs (83%), flexures (76%), upper limbs (71%) and neck (65%). Itch intensity during its peak was nearly twice higher than the itch of a mosquito bite. Itching was most frequent at night (65%), and 84% of patients reported of difficulty falling asleep. Daily life activities which increased the severity of itch were sweat in 96%, dryness in 71%, stress in 71% and physical effort in 73%. The major factors which were found to reduce the intensity of pruritus included: bathing with cold water in 55% and cold ambient environment in 56%. Associated symptoms were heat sensation (51%), sweating (40%) and pain in the pruritic area (45%). The various anti-pruritic therapies had limited long-term effect. The pruritus was bothersome (52%) and a major distress to the patient. The affective score correlated to itch intensity during its peak (r = 0.4, P < 0.001).

CONCLUSIONS

The study provided a detailed description of pruritus in atopic dermatitis with new data on affective and sensory dimensions and associated symptoms. The questionnaire was found to be a useful tool in characterization of itch.

Double-blind placebo-controlled house dust mite control measures in adult patients with atopic dermatitis

BACKGROUND

Avoidance of allergens has been shown to be of benefit in patients with atopic asthma sensitized to indoor allergens. In atopic dermatitis, there is so far little information about the effect of house dust mite elimination strategies.

OBJECTIVES

We therefore performed a randomized controlled study of house dust mite control in patients with this disease.

METHODS

Twenty adult patients with moderate to severe atopic dermatitis were included. Inclusion criteria were a positive RAST to house dust mite antigen (CAP class > 3) and a concentration of > 2 microg g(-1) of the house dust mite antigen Der p1 in the patient's mattress dust. Patients were randomized to either the active treatment group (allergen-impermeable mattress encasing, acaricide spray containing tannic acid and benzylbenzoate) or a control group (allergen-permeable encasing, spray containing water and traces of ethanol). Severity of disease was estimated every 2 months by an established score (SCORAD), and eosinophil cationic protein (ECP) in the serum was determined by enzyme-linked immunosorbent assay. Furthermore, the use of topical steroids was quantified. Patients assessed daytime pruritus and pruritus-induced sleeplessness weekly on a visual analogue scale. The study lasted 1 year.

RESULTS

At the end of the study, the active treatment group showed a statistically significant reduction in Der p1 exposure as compared with the control group. However, when comparing the change from the start to the end of the study, there was no statistically significant difference between active treatment and control groups as measured by the SCORAD score and by ECP levels in the serum. Some patients in the active treatment group reported less pruritus-induced sleeplessness, but there was no statistically significant difference between the two treatment groups.

CONCLUSIONS

For adult patients with atopic dermatitis it was shown that 1 year of house dust mite avoidance reduced the allergen exposure, but an improvement of overall disease activity was not demonstrated.

Use of a wrist activity monitor for the measurement of nocturnal scratching in patients with atopic dermatitis

BACKGROUND

The amount of nocturnal scratching can be an indirect correlate of itch in pruritic dermatoses. We have previously used an infrared video camera to measure nocturnal scratching in atopic dermatitis (AD). Although this is a reliable method of measuring nocturnal scratching, it is not suitable for routine monitoring in clinical use.

OBJECTIVES

To find a simplified way of monitoring itch.

METHODS

We tried using a wrist activity monitor (ActiTrac) for the measurement of nocturnal scratching in patients with AD. ActiTrac is a wristwatch-shaped device that contains a piezoceramic sensor to measure and record limb movement over a pre-set time interval. The acceleration signal produced by motion of the hands is stored and downloaded into a personal computer. The average value of acceleration (AVA, 10(-3) g min(-1)) was calculated and compared with total scratching time as a percentage of total recording time (TST%) measured with the use of an infrared video camera in 63 recordings of 21 patients with AD. For 261 recordings in 29 patients with AD, the AVA was measured and correlated with disease severity, and compared with the AVA of five non-itchy controls.

RESULTS

There was a significant correlation between the AVA and TST% (r = 0.91, P < 0.001), and a regression equation of y = 0.44x - 2.5 was obtained. The AVA correlated well with the severity of AD and definitely differed from the results observed in normal controls. The AVA (mean +/- SD) was 44.4 +/- 19.1 for 115 recordings in patients with severe AD, 23.2 +/- 10.9 for 89 recordings in patients with moderate AD, 8.9 +/- 6.0 for 57 recordings in patients with mild AD and 4.1 +/- 1.9 for 25 recordings in five normal controls. The units used here are arbitrary units min-1 with a range of 0--250, which corresponds to 0-75 x 10(-6) g min(-1).

CONCLUSIONS

A wrist activity monitor is able to measure nocturnal scratching. However, further methods of analysis should be sought to select scratching activity exclusively.

Characterization of itch-associated responses of NC mice with mite-induced chronic dermatitis

To clarify the behavioral and pathological features of spontaneous scratching of NC mice with mite-induced chronic dermatitis, we investigated the spontaneous and pruritogen-evoked scratching of NC mice. Although the frequency of scratching of NC mouse did not increase under specific pathogen-free environment, it gradually and markedly increased from 3 to 6 weeks after transfer to conventional environment. The onset of increase in spontaneous scratching was similar to that of dermatitis development and the elevation of plasma concentration of immunoglobulin E. At chronic stage (16 weeks after environment change), the frequency of spontaneous scratching was roughly parallel to the degree of dermatitis, but not to the plasma concentration of immunoglobulin E. The spontaneous scratching of NC mice with dermatitis was inhibited by distraction and the opioid antagonist naltrexone, suggesting that the scratching is itch-associated response. An intradermal injection of serotonin, but not histamine and substance P, elicited scratching of the injected site. Methysergide and cyproheptadine inhibited the serotonin-induced scratching but not spontaneous scratching. The results suggest that marked elevation of plasma immunoglobulin E is not always the cause of spontaneous itch-associated response of NC mice with dermatitis. Serotonin, histamine and substance P may not play an important role in spontaneous itch-scratch response at a chronic stage.