Clinical characteristics of pruritus in chronic idiopathic urticaria

BACKGROUND: Although pruritus is a predominant symptom of chronic idiopathic urticaria (CIU) its clinical characteristics have not been explored. OBJECTIVES: To characterize the clinical pattern and sensory and affective dimensions of the itch experience, utilizing a comprehensive itch questionnaire. METHODS: A structured questionnaire based on the McGill pain questionnaire was used in 100 patients suffering from CIU randomly recruited from a tertiary referral centre. RESULTS: All 100 patients recruited with CIU completed the questionnaire. In 68 patients pruritus appeared on a daily basis. Most patients experienced their pruritus at night and in the evening (n = 83), and 62 reported difficulty in falling asleep. Pruritus involved all body areas, but mostly the arms (n = 86), back (n = 78) and legs (n = 75). Accompanying symptoms were a sensation of heat in 45 patients and sweating in 15. Most patients (n = 98) were prescribed antihistamines (mainly sedating), of whom 34 experienced long-term relief. The sensation of itch was reported to be stinging (n = 27), tickling (n = 25) and burning (n = 23). Seventy-six patients found their pruritus bothersome, 66 annoying and 14 complained of depression. The itch intensity at its peak was more than double that felt after a mosquito bite. The worst itch scores of those who felt depressed were significantly higher than of those who did not (P = 0.018). There was a positive correlation between the sensory and affective scores during worst itch (P < 0.001). CONCLUSIONS: This study describes the itch experienced in CIU, highlighting sensory and affective dimensions. The itch questionnaire was found to be a valuable tool for evaluating pruritus in CIU and its unique features.     

Clinical characteristics of generalized idiopathic pruritus in patients from a tertiary referral center in Singapore

BACKGROUND: Generalized idiopathic pruritus is a rarely studied heterogeneous condition, where patients with non-inflamed, non-pathologic skin complain of widespread pruritus. METHODS: We had administered a detailed pruritus questionnaire, based on the short form of the McGill pain questionnaire, on 75 patients with this condition. RESULTS: All 75 patients recruited with generalized idiopathic pruritus completed the questionnaire. In 92% of the patients, pruritus appeared on a daily basis. Most patients experienced pruritus at night (56%) and in the evening (61%) and 69% had difficulty falling asleep. Pruritus mainly involved the legs (79%), arms (76%) and back (68%). Accompanying symptoms were heat sensation (17%) and pain (13%). 80% had been prescribed antihistamines, of whom 56% obtained short-term relief. The sensation of itch has been reported to be crawling (33%), tickling (20%), stinging (19%) and burning (19%). Patients also reported that the itch was unbearable (73%), bothersome (72%), annoying (67%) and worrisome (45%). The worst-state VAS scores were significantly higher in patients who reported agitation (P = 0.006), difficulty in concentration (P= 0.010) and anxiety (P= 0.033). CONCLUSION: This study describes the sensory and affective dimensions of generalized idiopathic pruritus, and this questionnaire has been found to be a useful tool for evaluating pruritus in this condition.     

Pathophysiology of pruritus in atopic dermatitis: an overview

Pruritus is an essential feature of atopic dermatitis (AD) and the diagnosis of active AD cannot be made without the history of itching. Because of the high impact on life quality, most of the patients measure the severity of eczema by the intensity of pruritus rather than appearance of skin lesions. However, although pruritus is a cardinal symptom of AD, its mechanism and association with the cutaneous nervous system is not completely understood. Recently, a considerable progress has been achieved in clarifying the complex pathophysiology of pruritus in AD. As a cutaneous sensory perception, itch requires excitation of neuropeptide-containing free nerve endings of unmyelinated nociceptor fibers. It is well known that histamine and acetylcholine provoke itch by direct binding to 'itch receptors' and several mediators such as neuropeptides, proteases or cytokines indirectly via histamine release. Interestingly, some variations of these complex mechanisms could be demonstrated in patients with AD. This review highlights the recent knowledge of different mechanisms which may be involved in regulating pruritus in patients with AD potentially leading to new therapeutic applications for the treatment of itch in AD.     

特应性皮炎瘙痒机制的研究进展

瘙痒是特应性皮炎的一个基本特征。因为瘙痒严重地影响着生活质量，大部分患者判断特应性皮炎的严重程度是通过瘙痒的剧烈程度而不是皮疹的表现。但其发生机制尚不完全清楚。最近，在研究特应性皮炎瘙痒的机制方面已取得很大的进展，既有神经系统的兴奋，又有一些介质的作用。这些进展为特应性皮炎患者瘙痒的研究和治疗提供新的思路。     

Itch intensity evaluated in the German Atopic Dermatitis Intervention Study (GADIS): correlations with quality of life, coping behaviour and SCORAD severity in 823 children

The German Atopic Dermatitis Intervention Study (GADIS), which includes 823 children and adolescents, showed that age-related educational programmes are effective in the long-term management of atopic dermatitis. We investigated whether the itch severity obtained in the scoring of atopic dermatitis (SCORAD) correlates with quality of life and coping behaviour in children and parents. There were significant but low correlations between the severity of atopic dermatitis and the itch intensity. Itch and sleeplessness were significantly correlated. Significant correlations of itch with the coping behaviour and quality of life in parents of children with atopic dermatitis were measured. The coping and itching behaviour of children (8-12 years) and adolescents (13-18 years) had higher significant correlations with the itch compared with the parents' answers. Quality of life in children (8-12 years) and adolescents (13-18 years) showed a significant negative correlation with itch intensity. Quality of life, itch intensity and coping strategies should be considered when treating patients with atopic dermatitis.     

Atopy patch test--reproducibility and elicitation of itch in different application sites

We evaluated the reproducibility of atopy patch test reactions and the quality and quantity of itch in 16 patients with atopic eczema and a history of a positive atopy patch test reaction, comparing three different application sites. The allergen was re-applied simultaneously on both forearms and the back. Intensity and quality of pruritus were evaluated using a visual analogue scale and the Eppendorf itch questionnaire, respectively. The atopy patch test reaction was highly reproducible, occurring in 15/16 (94%) patients. Pruritus was reported by 14/16 (88%) patients. There was no significant difference in either the intensity or quality of itch between the two forearms and the back (p>0.05). The mean peak visual analogue scale itch score was comparable across all three test sites (range 28.3-31.9). Regarding quantification of test reactions, a positive reaction was more frequent on the back (94% versus 69% on the arms) and the peak atopy patch test score was higher on the back compared with the arms (right forearm, p=0.0018 and left forearm, p=0.0683). Allergens should preferably be applied on the back for the atopy patch test. However, the atopy patch test can induce atopic itch irrespective of the application site.     

Itching in the psychiatric ward

Chronic itch is known to have psychogenic elements; however, there is no data on itch prevalence and characteristics among hospitalized psychiatric patients. We investigated the prevalence and types of itching among hospitalized psychiatric patients who met DSM-IV criteria for schizophrenia, affective or other psychiatric disorders. A validated itch questionnaire based on the McGill Pain Questionnaire, which examines the incidence and characteristics of itching, was administered to 111 patients, hospitalized in an Israeli university hospital. Patients with atopic eczema, psoriasis, or systemic diseases that cause pruritus were excluded. Thirty-six patients (32% of those screened) reported itching. Few sought help or used anti-pruritic therapy. Itching should be addressed during psychiatric assessments, in order to provide appropriate treatment.     

Impact of acute stress on itch sensation and scratching behaviour in patients with atopic dermatitis and healthy controls

Patients with atopic dermatitis (eczema) often report that stress is a major factor to worsen their itchy skin. This study investigated the effects of acute stress on itch, urge to scratch, and scratching behavior in subjects with atopic dermatitis compared to healthy controls. Stress was created in a standardized way using the Trier Social Stress Test (TSST), where subjects were asked to perform a public speaking task and mental arithmetic. In a second control visit, instead of being stressed, subjects watched a non-stressful video of landscape scenes. Both subjects with atopic dermatitis and healthy subjects reported feeling stressed after the TSST. Interestingly, atopic dermatitis subjects who were more sensitive to stress also had higher eczema severity. Before and after the TSST or landscape video, cowhage (a plant that causes itch) was applied to the arm of each subject. Patients with atopic dermatitis reported less itch from cowhage and less urge to scratch after they had been stressed by the TSST. However, despite reporting less itch, they actually scratched their limbs significantly more when they were stressed. Healthy individuals did not have any difference in itch, urge to scratch, or scratching behavior in the stressful condition compared to the control landscape video condition. This study shows that acute stress can affect itch and scratching differently in chronic itch patients compared to healthy individuals. Stress led to more scratching in those with atopic dermatitis. Over time, this response to stress could lead to increased skin damage from scratching and therefore worse eczema and itch.     

Treatment of atopic dermatitis with the xenon chloride excimer laser

BACKGROUND: Narrow-band ultraviolet B phototherapy is an effictive and safe treatment for atopic dermatitis. We have previously found that the 308 nm xenon chloride excimer laser was more effective than the narrow-band ultraviolet B light for the treatment of psoriasis, suggesting that ultraviolet B laser might offer advantages over narrow-band ultraviolet B. OBJECTIVE: The purpose of this study was to evaluate the therapeutic efficacy of the 308 nm excimer laser in atopic dermatitis. PATIENTS AND METHODS: Fifteen patients with atopic dermatitis (less than 20% body area involvement) were treated with a xenon chloride excimer laser (XTRAC laser, Photomedex Inc.) twice weekly. The severity of the atopic dermatitis was assessed via (i) a clinical score characterizing the intensity of erythema, infiltration, lichenification and excoriation; (ii) the quality of life, determined by means of a questionnaire; and (iii) a visual linear analogue scale, with which the patients scored the severity of their pruritus. RESULTS: After 1 month of laser therapy, the clinical scores were significantly lower than the initial values. Similar decreases were observed for the quality of life and pruritus scores. No serious or unpleasant side-effects were observed. CONCLUSION: These results suggest that the xenon chloride excimer laser is an effective and well-tolerated treatment for localized atopic dermatitis.     

Sexuelle Selbstreflexion bei Patienten mit Neurodermitis und Psoriasis

Objective

The aim of this study was to evaluate the differences between the Sexual Self-Reflection in patients with atopic dermatitis and psoriasis from a group of healthy controls. Furthermore the influence of coping with the disease and pruritus on the patients’ sexuality was studied

Methods

Patients with atopic dermatitis (n=38), psoriasis (n=31) and healthy controls (n=33) were tested with various psychological questionnaires. The German questionnaire for partnership attributes (PFB), Marburg questionnaire for coping with skin diseases (MHF) and questionnaire for pruritus and cognition (JKF), and sexual self-concept questionnaire (MSSCQ) served as psychometric measures.

Results

Patients with atopic dermatitis showed more fears of sex, with pruritus being the main factor, so that controlling pruritus should also improve sexual experience. Patients with psoriasis and sexual problems showed significantly more social fears and avoidance.

Conclusion

Appropriate psychosomatic care and educational programs including the therapy of social fears, avoidance and pruritus may also improve sexual life in patients with psoriasis or atopic dermatitis.     

Effects of tacrolimus ointment on facial eruption, itch, and scratching in patients with atopic dermatitis

The action of tacrolimus ointment on pruritus in atopic dermatitis is still unclear. In this open study we investigated both the relationship between the severity of eruptions and the degree of itch and scratching in patients with atopic dermatitis and the effects of topical tacrolimus on these symptoms. Seventy adults with moderate to severe atopic dermatitis with facial eruptions that were recalcitrant to topical steroids applied a 0.1% tacrolimus ointment twice per day after discontinuation of topical steroid. The eruption scores and an assessment of the itch and scratching were recorded for 12 weeks. Oral antihistamine was prescribed at least one month before the study and continued unchanged during the study in each patient. The percentage reduction in the score of itch and scratching after two weeks (n=59) was significantly higher than in the score of eruption. Although there was no significant relationship between the severity of the eruptions and the degree of itch and scratching during steroid application, a relationship became significant after four weeks (n=59) of tacrolimus use by a one-factor ANOVA analysis. This suggests that tacrolimus ointment is effective for the itch and scratching in cases where degrees might be discrepant from the severity of eruptions in patients with recalcitrant facial eruptions of AD.     

Improvement of pruritus and quality of life of children with atopic dermatitis and their families after joining support groups

Introduction  Atopic dermatitis places a large burden on patients and their families, with greater risk of emotional disorders and behavioural problems. Preliminary evidence suggests that support groups and educational programs are helpful in reducing stress, disease and pruritus severity and improves quality of life (QoL).
Objectives  To evaluate the intensity of pruritus and the QoL in children with atopic dermatitis and their families after joining support groups.
Material and methods  Subjects were randomly assigned to intervention or control group and completed the Children's Dermatology Life Quality Index (CDLQI) and Family Dermatitis Impact (FDI). Pruritus was evaluated by the Yosipovitch's questionnaire for pruritus. Each patient/family unit was considered as one 'patient'. Participants were divided into two different groups: one with children under 16 years and the second with patients' relatives. Each unit was accompanied during 6 months.
Results  Thirty-two patients and their relatives completed the questionnaires satisfactorily. After intervention, pruritus intensity was similar ( P =  0.42), but the pattern of pruritus improved in the intervention group. Overall QoL for CDLQI instruments improved significantly ( P <  0.01) and, when specific domains were analysed, personal relationships ( P =  0.02) and leisure ( P =  0.04) showed marked enhancement. FDI scores failed to demonstrate differences in the QoL of patients' relatives after treatment.
Conclusion  The improvement on pruritus and QoL showed that atopic dermatitis patients had benefits with the attendance to support groups. We consider that these non-pharmacological approaches can be a very effective accessory tools in the management of recalcitrant forms of the disease.     

Repetitive scratching and noxious heat do not inhibit histamine-induced itch in atopic dermatitis

BACKGROUND: Repetitive scratching is the most common behavioural response to itch in atopic dermatitis (AD). Patients with chronic itch often report that very hot showers inhibit itch. We recently reported that scratching and noxious heat stimuli inhibit histamine-induced itch in healthy subjects. However, no psychophysical studies have been performed in AD to assess the effects of repetitive heat pain stimuli and scratching on histamine-induced itch. OBJECTIVES: To examine the effects of repetitive noxious heat and scratching on itch intensity in patients with AD using quantitative sensory testing devices. METHODS: Itch was induced with histamine iontophoresis in 16 patients with AD in both lesional and nonlesional skin as well as in 10 healthy subjects. Repetitive noxious heat and scratching were applied 3 cm distal to the area of histamine iontophoresis. Subjects rated their perceived intensity of histamine-induced itch with a computerized visual analogue scale. RESULTS: Our results demonstrate that repetitive noxious heat and scratching do not inhibit itch intensity in lesional and nonlesional AD skin but do so in healthy skin. Of note, both these stimuli increase itch intensity in lesional AD skin. CONCLUSIONS: Our results strongly suggest that scratching and noxious thermal stimuli have a different effect upon histamine-induced itch perception in patients with AD when compared with healthy controls. This difference may be associated with both peripheral and central sensitization of nerve fibres in AD.     

Electrode design for skin electroporation with minimal nerve stimulation

Itch is one of the major symptoms of various skin diseases. Although specific neuronal pathways for itch were identified both peripherally and centrally, they still fail to explain itchy skin observed in patients with chronic pruritus. In this study, sensitivity to itchy and painful stimuli in patients with atopic dermatitis was investigated. Histamine-prick evoked enormous itch in their lesional skin, while less itch in their non-lesional skin than healthy subjects. Flare reaction was not significantly different between their non-lesional and lesional skin, rather smaller than healthy subjects. Mechanical (pin-pricks), electrical, heat and chemical (injection of pH3 solution) stimuli evoked intense itch in their lesional skin and partly also in their non-lesional skin, while only pain in healthy subjects. Itch was also, but not intensely, evoked in healthy subjects by injection of pH3 solution after sufficient histamine stimuli. These results confirm the presence of itchy skin with hyperkinesis (excessive itch by itchy stimuli) and allokinesis (itch by non-itchy stimuli) in patients with atopic dermatitis, which is so intense that painful stimuli cannot suppress but evoke itch, and suggest that neuronal sensitization is involved in their itch not only peripherally but also centrally.     

Neuronal sensitization for histamine-induced itch in lesional skin of patients with atopic dermatitis

OBJECTIVE: Lowered threshold of neurons (ie, neuronal sensitization) in atopic dermatitis was investigated by testing sensitivity to histamine. DESIGN: Comparative study. SETTING: A dermatological clinic and a research laboratory. PARTICIPANTS: Eighteen patients with atopic dermatitis (AD) and 6 patients with chronic plaque-type psoriasis as well as 14 healthy control subjects. INTERVENTIONS: Histamine prick was performed in lesional and nonlesional skin of patients and in control subjects. MAIN OUTCOME MEASURES: Axon reflex flare and wheal were measured planimetrically, and the itch intensity was rated on a numerical scale (0-10). RESULTS: In nonlesional skin of patients with AD, itch intensity and axon reflex flare were both significantly smaller compared with controls (mean +/- SEM maximum itch, 1.5 +/- 0.3 vs 3.1 +/- 0.2 [P<.05]; mean +/- SEM diameter, 12.3 +/- 2.0 vs 25.3 +/- 2.5 mm [P<.01]). In lesional skin of patients with AD, on the contrary, massive itch was provoked (maximum itch, 4.4 +/- 0.3), although flare was relatively small (diameter, 16.1 +/- 3.4 mm). Itch ratings in patients with psoriasis were low both in lesional and nonlesional skin (maximum itch, 1.3 +/- 0.6 and 1.0 +/- 0.4, respectively). CONCLUSION: As the area of axon reflex flare is an indirect measure of activity in primary afferent neurons, our results suggest a decreased activation of peripheral pruriceptors in patients with AD. The massively increased itch in lesional skin of patients with AD might therefore be based on sensitization for itch in the spinal cord rather than in primary afferent neurons. This sensitization does not appear to be simply based on skin inflammation because histamine-induced itch was not augmented in lesional skin of psoriasis.