Pruritus: more scratch than itch

Effectiveness of Postburn Pruritus Treatment and Improvement of Insomnia-A Randomized Trial

Postburn pruritus is difficult to assess and treat. Antihistamines used in its treatment provide little relief. Identification of the itch neuronal pathway has inspired new alternatives, including gabapentin, for its management. The study compared the effectiveness of cetirizine, gabapentin, and a combination of gabapentin and cetirizine in treating postburn pruritus. Burn patients were randomly assigned to treatment with Cetirizine (n = 23), Gabapentin (n = 23), or Cetirizine plus Gabapentin (n = 23). A baseline assessment of the intensity or the severity of pruritus was evaluated, after which treatment commenced with standard doses of the 3 study regimens. Quality of sleep was assessed at baseline (day 0) and repeated on day 3, day 7, and day 14. Approximately 97% of participants presented with moderate or severe itch; 69% with acute itch; and the majority (94.2%) experienced pruritus between the first and fourth weeks. Gabapentin reduced itch by 92.9% in 14 days compared to cetirizine's 61.8%. The combined effect of cetirizine and gabapentin was comparable using gabapentin alone. When the itch became protracted over 6 weeks, the effectiveness of cetirizine in controlling itch worsened. It reduced itch intensity by only 37.7%, whilst gabapentin did so at 89.4%. Itch intensity correlated positively with insomnia, and controlling itch intensity improved sleep. Gabapentin was more effective for the treatment of postburn pruritus than cetirizine. Controlling itch intensity improved sleep. In acute and moderate itch, low-dose gabapentin could be added if cetirizine is the drug intended for its treatment.

Validation of the Dutch version of the itching cognitions questionnaire

The purpose of this study was to examine the reliability and validity of the Dutch itching cognitions questionnaire (ICQ). This by origin German questionnaire, the Juckreiz Kognitons Fragebogen consists of two subscales: catastrophizing and helpless coping and problem-focused coping, and measures itch-related coping. The results were compared with the German and Japanese validation studies. The Dutch ICQ was completed by 171 patients with chronic pruritic skin diseases. Reliability was evaluated by determining internal consistency, mean inter-item correlation, and item-total correlation. Cronbach's alpha was .90 (catastrophizing and helpless coping) and .81 (problem-focused coping). The mean inter-item correlations for the subscales were .48 (catastrophizing and helpless coping) and .30 (problem-focused coping). The item-total correlations range from .57 to .76 (catastrophizing and helpless coping) and from .32 to .57 (problem-focused coping). Confirmatory factor analysis indicated a good fit of the model and support construct validity. Concurrent validity was determined by examining correlations of the ICQ with intensity of itching and scratching, depression, and anxiety. The correlations of the subscale catastrophizing and helpless coping with intensity of itching and intensity of scratching are .28 (p < .01) and .32 (p < .01), respectively. The correlation between the subscale problem-focused coping and intensity of itching is .23 (p < .01). No significant correlation exists between problem-focused coping and intensity of scratching. Correlations between both subscales and anxiety and depression vary from .33 to .58 (p < .01). It was concluded that the Dutch version of the ICQ is a reliable and valid instrument.

Are subjective accounts of itch to be relied on? The lack of relation between visual analogue itch scores and actigraphic measures of scratch

There is a widespread belief that subjective accounts of disease are key components of measures of disease severity and quality of life. In the present study we have set out to test this hypothesis using visual analogue scales (VAS) for itch, as a subjective measure, and actigraphy as an objective measure. One-hundred and seventeen itchy children and adults (and 25 controls) were studied for clusters of nights (total number 1,654) and actigraphy scores and VAS itch taken daily. Fifty-six percent of the night-to-night variation in actigraphy scores occurred between different individuals, while 44% was intra-subject. Neither age nor sex (children's or adults') predicted actigraphy scores, and the only significant predictor of actigraphy score was disease type (p = 0.001, r² = 0.51). In a multivariate model VAS itch score was not a significant determinant of actigraphy scores for either children or adults (p = 0.26). In order to see if there was a relation between VAS itch and actigraphy within the same patients (rather than between patients), 20 eczema patients wore the actigraph and scored VAS itch nightly for 42 nights. Little relationship was found between the actigraphy score and the VAS itch. Empirical autocorrelation analysis of VAS itch and actigraphy score reveal a clear autocorrelation for subjective VAS scores that was not found for the objective actigraphy score. Our data suggest a dissociation between scratch and perceived or recalled itch. One explanation is that VAS itch scores suffer from considerable anchoring, and context bias, and that their use in measures of disease severity is problematic.

Itch in the community: associations with psychosocial factors among adults

BACKGROUND

Itch is a major symptom in dermatology but is little explored epidemiologically. Objective To describe the prevalence and the severity of itch, and to explore its relation to psychosocial factors.

METHODS

The design was cross-sectional and population-based. A total of 40 880 adults in Oslo were invited to answer a questionnaire.

RESULTS

Twenty-seven per cent report itch. Individuals reporting itch were younger, the majority were female, were non-Norwegian, had lower income, were more distressed, had experienced more negative life events and had poorer social support. Individuals with poor support who had experienced more negative life events reported more itch than individuals with good support (15. 6% compared to 10. 9%). The strong association with psychosocial factors was confirmed in a logistic regression.

CONCLUSION

There is a strong association between itch and psychosocial factors in the general population.

Pathophysiology of nocturnal scratching in childhood atopic dermatitis: the role of brain-derived neurotrophic factor and substance P

BACKGROUND

Childhood atopic dermatitis (AD) is a distressing disease associated with pruritus and sleep disturbance. The pathophysiology of pruritus is complex and various neuropeptides may be involved.

OBJECTIVE

To evaluate whether or not brain-derived neurotrophic factor (BDNF) and substance P are associated with disease severity, quality of life and nocturnal scratching in AD.

METHODS

Patients with AD aged under 18 years were recruited. Disease severity was assessed with the SCORing Atopic Dermatitis (SCORAD) index, and quality of life with the Children's Dermatology Life Quality Index (CDLQI). Concentrations of plasma BDNF, substance P, AD-associated chemokines [cutaneous T-cell attracting cytokine (CTACK), thymus and activation regulated chemokine (TARC)], serum total IgE and eosinophil counts were measured in these patients. All children were instructed to wear the DigiTrac monitor on their dominant wrist while sleeping. The monitor was programmed to record limb motion between 22.00 and 08.00 h the following morning.

RESULTS

Twenty-eight children with AD [mean (SD) age 11.1 (3.3) years] were recruited. The mean (SD) SCORAD was 48.1 (21.5) and CDLQI was 8.7 (5.4) in the patients with AD. Their mean (SD) plasma concentrations of BDNF, substance P, CTACK and TARC were 1798 (935), 94 (42), 1424 (719) and 824 (1000) pg mL(-1), respectively. BDNF was significantly correlated with SCORAD (r = 0.478, P = 0.010) and CDLQI (r = 0.522, P = 0.004), whereas substance P showed significant correlation only with CDLQI (r = 0.441, P = 0.019). BDNF and substance P were also significantly correlated with the average (r = 0.905, P < 0.001 and r = 0.925, P < 0.001) and frequency-specific (r = 0.826, P < 0.001 and r = 0.870, P < 0.001) nocturnal wrist activities measured by DigiTrac. However, there was no correlation between BDNF or substance P and the subjective symptoms of pruritus or sleep-loss scores as reported by the parents in the SCORAD. In contrast, serum total IgE levels showed significant correlations with the subjective symptoms of pruritus (r = 0.576, P = 0.001) and sleep loss (r = 0.419, P = 0.027).

CONCLUSIONS

Serum levels of BDNF and substance P correlate with the clinical score and quality of life score in patients with AD. The strong correlations with nocturnal wrist movements suggest that they may be the pathogenic factors of the annoying symptoms of scratching.

Effectiveness of the nursing programme 'Coping with itch': a randomized controlled study in adults with chronic pruritic skin disease

BACKGROUND

The nursing programme 'Coping with Itch' aims at reducing itch and at helping patients with chronic pruritic skin diseases cope with itch. The programme consists of educational and cognitive behavioural interventions. Dermatology nurses carry out the programme, which supplements standard medical treatment given by a dermatologist, in individual sessions at a nurse clinic organized by the dermatology outpatient department.

OBJECTIVES

To evaluate the effectiveness of the nursing programme 'Coping with Itch' in patients with chronic pruritic skin diseases.

METHODS

A randomized controlled study was carried out. Patients with chronic pruritic skin diseases were randomly assigned to the intervention group or the control group. The intervention group received standard care from a dermatologist and nursing care according to the programme 'Coping with Itch' for a mean of 2.9 visits. The control group received usual care from a dermatologist. Data collection took place at baseline, at 3 months (t1) and at 9 months (t2) after baseline. Most visits to the nurse clinic took place during the first 3 months of the study. Main outcome measures were the frequency and intensity of itching and scratching, itch-related coping, and skin-related and general psychosocial morbidity. Secondary outcome measures were the number of visits to the dermatologist and the use of medication and ointments. Mann-Whitney tests and analyses of covariance were used to analyse differences between the two groups.

RESULTS

Data on 29 patients in the intervention group and 36 patients in the control group were used in the analyses. A trend to significance (P = 0.07) was shown in the difference between the two groups in the frequency of itching and scratching at t1. A significant difference (P = 0.04) was shown between the two groups in catastrophizing and helpless itch-related coping at t1. No significant differences were revealed at t2 between the groups. Patients in the intervention group visited the dermatologist significantly less frequently during the intervention period than did control group patients.

CONCLUSIONS

The nursing programme 'Coping with Itch' led to a reduction in the frequency of itching and scratching and to a reduction of catastrophizing and helpless coping in patients with chronic pruritic skin diseases during the period immediately following the intervention. We suggest further follow-up visits to the itch clinic to extend these results over a longer period.

The nursing programme ?Coping with itch?: a promising intervention for patients with chronic pruritic skin diseases

AIMS AND OBJECTIVE

To examine the feasibility of the nursing programme 'Coping with Itch' and the effect of the programme on the frequency and intensity of itching and scratching, itch-related coping, skin-related psychosocial morbidity and quality of life.

BACKGROUND

Itch is a major symptom of many chronic skin diseases and has a considerable impact on the quality of life. Therefore, the nursing programme 'Coping with Itch' has been developed and implemented at the outpatient departments of dermatology of one university and one general hospital in the Netherlands. The programme is intended to reduce itch and to help the patient cope with his or her itch.

DESIGN AND METHODS

The feasibility of the programme has been determined by interviewing the nurses who carried out the programme, dermatologists and one medical social worker and by counting the number of visits and specific interventions. The effect of the nursing care programme 'Coping with Itch' was evaluated in 32 patients with pruritic skin diseases. Paired t-tests were used to determine its effect after three and nine months.

RESULTS

The nursing programme 'Coping with Itch' proved to be practically feasible. It leads to a significant reduction of the frequency and intensity of itching and scratching, to a significant reduction of catastrophizing and helpless coping and to a significant reduction of skin-related psychosocial morbidity in the short term. These results stabilized at nine months. No changes were found in the quality of life.

CONCLUSION

The nursing programme 'Coping with Itch' is a promising intervention for patients with chronic pruritic skin diseases.

Phospholipase Cbeta 3 mediates the scratching response activated by the histamine H1 receptor on C-fiber nociceptive neurons

Phospholipase Cbeta (PLCbeta) isozymes represent a family of molecules that link G protein-coupled receptors (GPCRs) to an intracellular signaling network. Here, we investigated the function of PLCbeta isozymes in sensory neurons by using mutant mice deficient for specific PLCbeta family members. Expression analysis indicated that PLCbeta3, one of the four isoforms, is predominantly expressed in a subpopulation of C-fiber nociceptors. A subset of these neurons expressed the histamine H1 receptor. Ca(2+) imaging studies revealed that PLCbeta3 specifically mediates histamine-induced calcium responses through the histamine H1 receptor in cultured sensory neurons. In line with this, we found that PLCbeta3(-/-) mice showed significant defects in scratching behavior induced by histamine; histamine-trifluoromethyl-toluidine (HTMT), a selective H1 agonist; and compound 48/80, a mast cell activator. These results demonstrate that PLCbeta3 is required to mediate "itch" sensation in response to histamine acting on the histamine H1 receptor in C-fiber nociceptive neurons.

Prevalence and predictors of psychosocial morbidity in patients with chronic pruritic skin diseases

BACKGROUND

Itch is a major symptom of many skin diseases and causes patients considerable distress, adversely affecting quality of life. Feelings of helplessness and lack of control can influence the perceived itch and psychosocial complaints.

OBJECTIVES

To determine the prevalence of psychosocial morbidity among patients with pruritic skin diseases, and the influence of itch-related variables, coping strategies, and demographic variables on psychosocial morbidity.

PATIENTS AND METHODS

One hundred and sixty-eight patients with pruritic skin diseases from five hospitals in the Netherlands participated in the study. Skin-related psychosocial morbidity was measured with the Adjustment to Chronic Skin Diseases questionnaire (ACS); general psychosocial morbidity was measured with the Symptom Checklist-90 (SCL-90). The frequency and intensity of itching and scratching was recorded in diaries. Itch-related coping was measured with the Itching Cognitions Questionnaire (ICQ). Multiple regression analyses were used.

RESULTS

Patients with pruritic skin diseases had higher SCL-90 scores than a healthy Dutch population. All patients had psychosocial complaints as measured with the ACS. Thirty-nine per cent of the variance in skin-related psychosocial morbidity was explained by 'catastrophizing and helpless coping'; another 11% was explained by itching and scratching. Age and sex together explained another 10%. The frequency of itching and scratching (11%), 'catastrophizing and helpless coping' (19%) and skin-related psychosocial morbidity (10%) explained the variance in general psychosocial morbidity.

CONCLUSIONS

Patients with a pruritic skin disease have a high level of psychosocial morbidity. Catastrophizing and helpless coping are the most important predictors of psychosocial morbidity, with itching, scratching and demographic variables having a limited influence.

Development of a psychological treatment service for pruritic skin conditions

The role of psychological contributions to common dermatological disease is increasingly recognized. It is often a challenge to find suitable psychological services to complement dermatological treatment. This paper describes the development of a psychological treatment service to reduce scratching behaviour found in common pruritic skin conditions. Our Department of Dermatology together with a consultation-liaison psychiatrist designed a four-session outpatient treatment programme incorporating psychiatric assessment, psychoeducation about the itch-scratch cycle, behavioural analysis, habit reversal techniques and between-session tasks for the patient to complete. This programme is actively modified in consultation with patients and their therapists to suit each patient's individual needs. Formal investigation is required to determine if this psychological treatment adds benefit in overall symptom control beyond dermatological treatment alone.

Itch and motivation to scratch: an investigation of the central and peripheral correlates of allergen- and histamine-induced itch in humans

Intense itch and urge to scratch are the major symptoms of many chronic skin ailments, which are increasingly common. Vicious itch-scratch cycles are readily established and may diminish quality of life for those afflicted. We investigated peripheral and central processing of two types of itch sensation elicited by skin-prick tests of histamine and allergen solutions. Itch-related skin blood flow changes were measured by laser Doppler in 14 subjects responsive to type I allergens and 14 nonatopic subjects. In addition, this study examined central processing of both types of itch using functional magnetic resonance imaging (fMRI). Itch perception and blood flow changes were significantly greater when itch was induced by allergens compared with histamine. Both types of itch correlated significantly with activity in the genual anterior cingulate, striatum, and thalamus. Moreover, itch elicited by allergens activated orbitofrontal, supplementary motor, and posterior parietal areas. Histamine-induced itch also significantly correlated with activation in the insula bilaterally. The identification of limbic and ventral prefrontal activation in two types of itch processing likely reflects the subjects' desire to relieve the itch sensation by scratching, and these regions have been repeatedly associated with motivation processing. A dysfunction of the striato-thalamo-orbitofrontal circuit is believed to underlie the failure to regulate motivational drive in disorders associated with strong urges, e.g., addiction and obsessive compulsive disorder. The patterns of itch-induced activation reported here may help explain why chronic itch sufferers frequently self-harm through uncontrollable itch-scratch cycles.

CDLQI, SCORAD and NESS: are they correlated?

BACKGROUND

Quality of life (QOL) and clinical severity scores are important parameters in the evaluation of distress experienced by children with atopic dermatitis (AD). The SCORing Atopic Dermatitis (SCOARD) is a widely used clinical score for assessing AD symptomatology over the preceding 3 days and the Nottingham Eczema Severity Score (NESS) is another score useful for AD symptoms over the preceding 12 months.

OBJECTIVE

We evaluated if these parameters are correlated with QOL in children with AD.

PATIENTS/METHODS

We assessed quality of life, clinical scores, total IgE and eosinophil count in peripheral blood in AD patients at our paediatric dermatology clinic over a 14-month period.

RESULTS

Eighty AD patients (42 males and 38 females; mean [SD] age 11.7 [3.7] years) were recruited. The median (interquartile range, IQR) IgE, eosinophil counts and eosinophil percentage were 2988 (1069-7847) kIU/L; 0.6 (0.4-0.9) x 10(-9)/L; and 9 (6-12)%, respectively. Quality of life as measured with CDLQI (The Children's Dermatology Life Quality Index) generally did not correlate well with both the acute and chronic AD severity scores (objective SCORAD and total CDQLI, rho = 0.17, p > 0.05; total NESS and total CDQLI, rho = 0.29, p < 0.05). Factor analysis further confirmed that the objective indicators (serum total IgE, eosinophil count and objective SCORAD), self-reported scores (NESS and subjective SCORAD) and CDLQI were separate dimensions in the assessment of AD in children.

CONCLUSION

Quality of life, disease severity scores and laboratory atopic markers represent different domains in AD assessment. They do not necessarily correlate well with each other and all three aspects must be individually evaluated to assess the well-being of these patients.

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.

Neuroanatomy and neurophysiology of itch

The specific pathway of "pure," histaminergic itch is traced from the mechano-insensitive nerve fibers in the skin to their central cortical projections. Neuropathic itch created at different levels of this anatomical pathway is reviewed. In this review the present author discusses damage to pruritoceptors in the skin, entrapment syndromes, damage to spinal ganglia, nerve root impingement, injury of the spinal cord, and cerebral damage in the distribution of the middle cerebral artery, capsula interna, or thalamus. Itch in inflamed skin resulting from interactions between nerve transmitters and other mediators of inflammation is described.

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.

Itching for progress

The study of itch remains a neglected field, with a number of barriers limiting satisfactory therapy in the majority of instances. We review recent advances, focusing on the identification of the neural pathways, distinct from pain, that signal itch; methods to measure itch as scratch in humans; and the identification of a role for H4 receptors in mediating itch (in the mouse).

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.

Itch associated with skin disease: advances in pathophysiology and emerging therapies

Itch, also known as pruritus, is the major symptom in skin diseases with a variety of etiologies and pathophysiologies. Significant progress has been achieved in understanding the pathophysiology of itch in the last 5 years. Neurophysiological experiments in humans and animals have revealed that itch is carried by specific C nerve fibers. Recent studies have demonstrated that peripheral mediators other than histamine are involved in induction of itch. Mast cell tryptase seems to be an important mediator in itch by its activation of proteinase activated receptor 2 in the sensory nerves. Opioids have central and peripheral itch producing activity. Neuropeptides, such as substance P, induce itch by their effect on mast cells. Based upon our improved understanding of the neurophysiology of itch a clinical classification of itch has been proposed. The classification highlights differences between peripheral pruritoceptive itch, neuropathic itch (itch related to damage to afferent nerve fibers) and neurogenic itch (itch originating in the central nervous system without any evidence of nerve damage). Emerging therapies based on these findings include topical vanilloid receptor antagonists, topical antihistamines, and topical arachidonic acid inhibitors, as well as inhibitors of non-histamine inflammatory mediators, immunomodulators and strontium salts. Systemic therapies include thalidomide, opioid antagonists, phototherapy with narrow band UVB and experimental treatments with cutaneous field stimulation and vagal nerve stimulation. With the new information it seems we will be able to better help our dermatologic patients who have itch, however we are not closer to identifying a single agent specifically targetable to this symptom.

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.

Efficacy measurement of topical antihistamines: a review

More and more antihistamines are used in gels or ointments for local antipruritic therapy. Among other factors, the efficacy is dependent on the penetration properties of the respective agents and the optimal choice of vehicle substances. To avoid expensive treatment with unsatisfying success, a reliable efficacy measurement would be desirable prior to the admission of new topical antihistamine preparations. Therefore we reviewed the literature for common methods to assess the efficacy of local antihistamines in healthy volunteers. The principle is to apply the test substance to marked test areas and to challenge the skin after a certain time with a standardised amount of histamine, allergens or mast-cell-degranulating substances. For the test evaluation, the areas of wheal, flare and itch are measured and compared between antihistamine-treated and control fields. Challenge models and most of the described evaluation methods are suited for the preliminary efficacy measurement of antihistamines. However, to be able to compare the results, a standardised procedure used by all investigators would be desirable.