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Itch is a common symptom, but there is limited evidence on the prevalence of itch in children. The aim of this study was to assess the prevalence of itch in schoolchildren. A questionnaire was developed by experts in the field and based on a literature search. The questionnaire was applied in a pilot study of 25 consecutively selected paediatric patients and their parents. It confirmed the high content validity of the questionnaire, and the questionnaire was comparable to hospital records regarding chronic itch (n = 19, mean consistency 89.47%). The questionnaire was distributed among German schoolchildren in 9/12 randomly selected primary schools in Kiel, Germany. Of 1,722 invited students, 443 schoolchildren aged 6-10 years participated, and 26.2% (n = 116) reported itch. The prevalence of acute itch was 20.0% (n = 87), and 14.7% (n = 65) reported chronic itch. Reduced sleep and mood were often related to chronic itch. This study demonstrated that itch is a common symptom in German schoolchildren. [ABSTRACT FROM AUTHOR]

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

Human hands are complex structures essential for a variety of functions in everyday life. This study prospectively investigated the clinical features of hand pruritus and the resulting functional impairment and disease-related burden in 395 patients with chronic pruritus (210 females, median age 59 years). Moderate to very severe hand pruritus was reported by 91.2% of patients, while 79% perceived additional sensory symptoms, such as burning, pain or tingling. A long duration of pruritus occurred in most cases (> 6 months: 71.4%). A considerable proportion of patients showed moderate to severe impairment in the use of their hands (40.2%), performance of daily activities (65.0%) and quality of life (45.2%). Disease severity and burden is particularly high when both the palms and the backs of the hands are affected, and when pain is present simultaneously. Pruritus located on the hands is impairing and burdensome due to the functional relevance of the hands in everyday life. [ABSTRACT FROM AUTHOR]

Chronic pruritus of unknown origin is established when no underlying origin for pruritus can be determined. This retrospective cohort study aimed to determine the clinical profile and disease-related burden of chronic pruritus of unknown origin. A total of 263 patients (female/male: 154/109, median age 55 years) were included. Moderate to severe itch intensities were recorded (median average itch: 5.5/10, n = 200; median worst itch: 7.5/10, n = 199). In most cases pruritus lasted longer than 1 year (77.6%), occurred daily (68.2%), occurred in attacks (72.8%), and was often accompanied by dysaesthesias, such as burning, tingling and stinging. Quality of life was moderately impaired, while 22.2% and 12.4% of patients showed pathological anxiety and depression scores. Scratch lesions were associated with higher intensities of itch and greater impairment of quality of life, while women were more burdened by the disease than men. Chronic pruritus of unknown origin may occur at any age and the majority of patients endure severe itch with substantial disease-related burden. [ABSTRACT FROM AUTHOR]

Chronic pruritus is a frequent global condition. The pathophysiology, underlying aetiology, clinical manifestation, associated burden and response to therapy of chronic pruritus varies from patient to patient, making clinical research and management of this condition challenging. There are still several unmet needs, such as the need to standardize translational research protocols, diagnostic and therapeutic procedures and to enhance the knowledge of the humanistic and economic burden associated with chronic pruritus. Basic and clinical research is of the utmost importance to target these matters. Clinical research has the potential to identify new relevant mechanisms in affected patients, which may lead to identification of novel therapy targets. This article discusses in depth current shortcomings in the daily care of patients with chronic pruritus and the challenges clinical researchers and physicians treating chronic pruritus face in addressing these matters. [ABSTRACT FROM AUTHOR]

Chronic pruritus is a bothersome symptom in psoriasis vulgaris and can profoundly reduce quality of life (QoL). In this exploratory analysis of the PSORITUS study, the impact of pruritus on QoL in 130 subjects with moderate-to-severe psoriasis was assessed using the ItchyQoL questionnaire. The majority of patients (n = 127) had to scratch their itchy skin regularly, which led to painful skin and frustration (mean ± standard deviation; SD ItchyQoL scores; 4.50 ± 0.56; 3.80 ± 1.09 and 4.20 ± 0.87, respectively). Changes in either temperature or season led to worsening of itching in most of the patients (n = 126; mean ± SD ItchyQoL score; 3.80 ± 1.02). Many patients felt ashamed (n = 125) or embarrassed (n = 127) due to their itchy skin (mean ± SD ItchyQoL scores; 3.90 ± 1.26 and 3.40 ± 1.19, respectively). The results demonstrated the ItchyQoL questionnaire as a validated tool responsive to treatment for detailed insights into chronic pruritus in patients with psoriasis. [ABSTRACT FROM AUTHOR]

Few studies have validated standard measurement instruments for evaluation of chronic pruritus. The Chronic Pruritus Tools Questionnaire PRURITOOLS assembles a set of instruments for the assessment of pruritus, such as the visual analogue scale (horizontal 100-mm line), numerical rating scale (0-10), verbal rating scale, and information on pruritus quality and improvement during therapy. This study, with 40 subjects, analysed PRURITOOLS regarding convergent validity and test-retest reliability (60 min), followed by a feasibility questionnaire. Test-retest reliability for PRURITOOLS items was excellent (intraclass correlation coefficient 0.84-1). Strong to very strong correlations between the pruritus intensity scales indicated convergent validity. The feasibility questionnaire showed an overall acceptance of PRURITOOLS, and the majority of subjects (82.5%) considered it an appropriate questionnaire to measure pruritus. In conclusion, PRURITOOLS offers validated tools for rapid pruritus assessment in routine care or endpoints of clinical trials. [ABSTRACT FROM AUTHOR]

Chronic pruritus (CP) is often accompanied by paresthetic sensations like warmth, burning and stinging. The aim of this study was to analyze, whether divergent sensations are linked to structural and functional skin alterations in clinically diagnosed CP patients. Clinical responses to capsaicin, histamine, and to thermal and mechanical stimulation, intraepidermal nerve fiber density, and epidermal expression of transient receptor potential (TRP)-channels were investigated in healthy controls, and in CP patients, reporting either warmth (CP-W) or neuropathic sensations (CP-N). In CP-W, pinprick hyperalgesia and increased sensitivity to capsaicin were aligned with increased epidermal TRPV1 expression, while smaller histamine axon reflex erythema matched with significantly reduced intraepidermal nerve fiber density. CP-N showed earlier onset of sensations after capsaicin stimulation, significantly increased warmth detection threshold, and higher epidermal expression of TRPV4 compared to healthy controls. The present study contributes to the neurobiological understanding of the divergence of sensory sensations in CP, indicating new treatment targets. [ABSTRACT FROM AUTHOR]

The aim of this multicentre, randomized, double-blind, placebo-controlled, cross-over, phase-II study was to determine the antipruritic effect of aprepitant vs. placebo in 58 patients with anti-histamine-refractory chronic pruritus in chronic nodular prurigo. Patients were randomized to receive either first oral aprepitant 80 mg/day or placebo for 4 weeks. Following a 2-week wash-out phase, the patients were crossedover to receive the other treatment for 4 weeks. Primary efficacy criterion was the intra-individual difference between mean itch intensity (visual analogue scale) at baseline compared with the end of treatment period. Prurigo lesions, pruritus course, quality of life, patient benefits, and safety were secondary parameters. No significant differences were found between aprepitant treatment and placebo for any of the parameters investigated. Under the experimental conditions of the study, aprepitant, 80 mg daily for 4 weeks, did not have an antipruritic effect in patients with chronic prurigo. [ABSTRACT FROM AUTHOR]

Chronic pruritus can be a diagnostic sign of an underlying disease. In the intracutaneous histamine test, histamine (one of the best-known inducers of pruritus) may cause different reaction patterns depending on the underlying disease. The aim of this study was to determine if an intracutaneous injection of histamine can differentiate between the causes of chronic pruritus and thus be used as a diagnostic test in chronic pruritus of unknown aetiology. A total of 140 subjects with chronic pruritus with various dermatological, systemic or neurological diseases were included. The intracutaneous histamine test was performed once on each subject. Erythema, wheal and pruritus intensity were measured and analysed. Significantly greater wheal size was observed in patients with systemic or multifactorial causes. In general, there was a significant correlation between age and wheal size. Also, noticeable differences were found between males and females regarding pruritus and wheal size. In summary, the exact type of chronic pruritus could not be clearly determined based on the results of the intracutaneous histamine test. However, the results provide valuable insights into specific reaction patterns to experimental histamine-induced itch, e.g. sex-specific differences in the neurophysiology of pruritus, which should be considered in future studies. [ABSTRACT FROM AUTHOR]

Impaired sleep due to nocturnal pruritus is a common symptom in patients with chronic pruritus. How ever, there is no standardized, simplified instrument for assessing sleep-related problems in patients with chronic pruritus. After a literature search, we conducted 50 interviews with patients with chronic pruritus and tested 12 items most frequently used in routine sleep questionnaires. Afterwards, 2 sleep assessment questionnaires (Pittsburgh Sleep Quality Index; Regensburg Insomnia Scale) were selected for use in 88 patients with chronic pruritus with sleep impairment due to pruritus. They were completed twice; once before optimizing their individual pruritus therapy and once again after 4 weeks. During the latter survey, 21 patients reported that pruritus no longer negatively affected their sleep. These patients also achieved a significant improvement in their sleeping behaviour in the Regensburg Insomnia Scale. Therefore, the Regensburg Insomnia Scale appears to be well-suited to assessing sleep impairment in patients with chronic pruritus. [ABSTRACT FROM AUTHOR]

Prurigo nodularis (PN) is a subtype of chronic prurigo presenting single to multiple symmetrically distributed, hyperkeratotic and intensively itching papules and nodules. PN evolves along with chronic pruritus in the context of diverse dermatological, systemic, neurological or psychiatric conditions. Permanent scratching is possibly a major trigger of PN, although its exact pathophysiology remains unclear. Current state-of-the-art therapy for PN consists of topical steroids, capsaicin, calcineurin inhibitors, ultraviolet (UV) therapy, systemic administration of gabapentinoids, µ-opioid receptor antagonists, antidepressants or immunosuppressants. Novel treatment concepts, such as inhibitors of neurokinin-1, opioid and interleukin-31 receptors, have been developed and are currently being clinically tested. [ABSTRACT FROM AUTHOR]

The central processing of itch is not completely understood. This is the first study to use functional magnetic resonance imaging (fMRI) to examine the central modulation by distraction of experimentally induced itch. A total of 33 healthy volunteers were examined with fMRI. Periods of itch induction without distraction and itch with distraction by a Stroop task (psychological test, where the participants have to decide if the colour of the writing corresponds to the written word, for example if "red" is written in red or not) were counterbalanced during the scanning to examine task-specific changes in blood oxygenation level dependent-signal. The intensity of the subjects' itch sensation, desire to scratch and pain sensation were evaluated. Distraction by a Stroop task did not reduce itch intensity or urge to scratch. However, the Stroop task led to significantly higher activation of the left brainstem when it followed the "pure" itch sensation. Itch and pain seem to have similar inhibition pathways, particularly concerning brainstem activation during distraction. But as itch sensation, in contrast to pain, could not be sufficiently reduced by distraction, both entities might have different modulation systems. [ABSTRACT FROM AUTHOR]

Performing a reliable assessment of chronic pruritus remains a challenge. Electronic diaries are often used, but many of the scales have not been validated. ItchApp© was developed for Android smartphones in order to address this lack. A total of 40 subjects with chronic pruritus completed questionnaires both on paper and with ItchApp© (verbal rating scale, numerical rating scale, dynamic pruritus score) in order to validate the software application. Strong correlations were found for test–retest reliability (intraclass correlation coefficient: 0.865-0.977) and convergent validity (Spearman's r: 0.442-0.924). A feasibility questionnaire for ItchApp© revealed a high level of user friendliness and compliance. This was confirmed in a randomized controlled trial with 68 subjects, for which the clinically important difference in the numerical rating scale values for ItchApp© was calculated (2.61 points). In summary, ItchApp© is a recently developed eDiary that can provide experts with a reliable evaluation of patients with chronic pruritus. It will be made available for future clinical trials. [ABSTRACT FROM AUTHOR]

Currently valid itch intensity scales, such as the visual analogue scale (VAS), are indispensable, but they can be influenced by the patient's overall health status. The aim of this study was to evaluate the reliability and validity of the Dynamic Pruritus Score (DPS), a new instrument comparing reduction in current pruritus with a defined earlier time-point. Eighty-one randomly selected adults (50 females, mean age 53.9 years) recorded their pruritus at visit 1 and repeatedly at visit 2 on the DPS, VAS, numerical rating scale, and on health status questionnaires (EuroQol; EQ-5D), skin-related quality of life (Dermatology Life Quality Index; DLQI), anxiety and depression (Hospital Anxiety and Depression Scale; HADS) and patient benefit (Patient Benefit Index; PBI). Intraclass correlation showed high reliability for both DPS and VAS (r > 0.9, p < 0.001), while the DPS has shown higher concurrent validity (rDPS to PBI = 0.570; p < 0.001). The DPS can then be considered an alternative instrument to the VAS for assessment of pruritus in adults. Further research is needed to confirm these results with a more representative sample size. [ABSTRACT FROM AUTHOR]

Patients with chronic pruritus may develop scratchinduced lesions with elevated borders and central necrosis. This so-called umbilicated type of prurigo (UP) is rare and is assumed to develop preferentially in the context of metabolic diseases. The aim of this study was to characterize UP in its clinical and histological dimension. Demographic and clinical data were collected from 23 patients with UP. Intensive light microscopical analysis of biopsied lesions was performed. Statistical comparison with previous results for prurigo nodularis (PN) showed that UP is clearly a subtype of PN. In addition, clinical and microscopic features of epidermal perforation identical to those in acquired reactive perforating dermatosis (ARPD) were observed. Hence, we suggest that ARPD is identical to UP and is therefore a subtype of PN. We assume that reduced wound healing capacities due to underlying systemic disorders, particularly diabetes mellitus and uraemia, underlie the pathomechanism of development of umbilicated skin lesions with a perforating aspect. [ABSTRACT FROM AUTHOR]

This study was a prospective, parallel-group, randomized, double-blind, vehicle-controlled, multi-centre clinical trial to compare the efficacy of topical sertaconazole 2% cream with vehicle in reducing chronic pruritus in subjects with atopic dermatitis, and to assess its safety and local tolerability. A total of 70 subjects applied either of the 2 treatments twice daily for a period of 4 weeks on affected, itchy skin areas. Treatment efficacy was evaluated primarily considering the item itch intensity on a 5-point verbal rating scale. Insomnia, state of atopic dermatitis (Scoring Atopic Dermatitis; SCORAD), quality of life and therapy benefit were also assessed. No significant difference between active treatment and vehicle was found at any of the time-points for any of the investigated parameters. Under the experimental conditions of the study, sertaconazole 2% cream did not exert anti-pruritic effects that were better than vehicle in subjects with atopic dermatitis who had chronic pruritus. [ABSTRACT FROM AUTHOR]

Pruritus is a frequent sensation in dermatoses, but its prevalence in patients in dermatological practices has not been fully studied. The aim of this cross-sectional study is to investigate its prevalence and characteristics in all patients attending a dermatology practice in Germany over a period of one week (n = 334; 52.7% female; median age 45.0 years). The point prevalence of pruritus in this study population was 36.2% (87.6% of whom had chronic pruritus). It inhibited the everyday life of 73.6% of all patients, with 77.7% reporting a frequently to permanently experienced moderate intensity. (5.2 ± 2.3 on the numerical rating scale). Of the patients, 52.1% had previously consulted their general practitioner, and 62% had visited the dermatologist due to pruritus. This study shows that pruritus is a highly prevalent, clinically and economically relevant symptom in dermatological practices. The majority of patients suffering from chronic pruritus are severely burdened and medically underserved. Dermatologists should be aware that pruritus also occurs frequently in patients who do not primarily present due to their symptoms. [ABSTRACT FROM AUTHOR]

Sensitive skin is a frequent complaint in the general population, in patients, and among subjects suffering from itch. The International Forum for the Study of Itch (IFSI) decided to initiate a special interest group (SIG) on sensitive skin. Using the Delphi method, sensitive skin was defined as "A syndrome defined by the occurrence of unpleasant sensations (stinging, burning, pain, pruritus, and tingling sensations) in response to stimuli that normally should not provoke such sensations. These unpleasant sensations cannot be explained by lesions attributable to any skin disease. The skin can appear normal or be accompanied by erythema. Sensitive skin can affect all body locations, especially the face". This paper summarizes the background, unresolved aspects of sensitive skin and the process of developing this definition. [ABSTRACT FROM AUTHOR]

Chronic pruritus is a common symptom and there is an urgent need to test new anti-pruritic substances in highquality clinical trials. However, no widely accepted standardized and validated method for objectively measuring pruritus is yet available. A special interest group of the International Forum for the Study of Itch has been established to assess scoring methods and questionnaires for use in clinical trials. This paper presents our current recommendations. The set of measures we recommend includes pruritus intensity scales, instruments for assessment of scratch lesions, chronic pruritus course, quality of life and patient benefitsen. [ABSTRACT FROM AUTHOR]

Chronic pruritus is frequently refractory to currently available treatments. Studies suggest that pruritus may arise from an imbalance of the mu- and kappa-opioid receptor system activity in either the skin or the central nervous system. Stimulation of kappa-opioid receptors by their agonists inhibits pruritus in both animals and humans. The antipruritic effect of kappa-opioid receptors agonists can currently be assumed to be related to their binding to kappa-opioid receptors on keratinocytes and cutaneous and/or central itch neurones. To date, several case reports and 2 controlled trials have demonstrated a beneficial effect of systemic kappa-opioid receptor agonists in the treatment of uraemic pruritus, prurigo nodularis, paraneoplastic and cholestatic pruritus. Nalfurafine hydrochloride (Remitch®), a selective kappa-opioid receptor agonist, is approved for the treatment of chronic pruritus in Japan. The aim of this review is to provide an overview of the promising role of kappa-opioid receptors and their agonist in the pathophysiology and treatment of pruritus. [ABSTRACT FROM AUTHOR]

Notalgia paraesthetica is a neuropathic pruritus on the back. The aim of this retrospective study was to examine patient characteristics in a consecutive cohort from Brazil and Germany. A total of 65 patients (49 women, 16 men; age range 25-80 years, mean 56.2 ±12.7 years; median 57.0 years) were investigated in order to determine the spinal or peripheral origin of notalgia paraesthetica. Protein gene product 9.5-positive intraepidermal nerve fibers were significantly reduced in the pruritic compared with the non-lesional area (p<0.05). In 32.3% of patients, radiological examinations showed a stenosis and in 47.7% a degeneration. A correlation between the radiological findings and the exact dermatomal localization of notalgia paraesthetica was found in 15.7% of the involved areas. The significant reduction in intraepidermal nerve fiber density suggests that damage to the peripheral nerves is a more important aetiological factor than spinal changes in notalgia paraesthetica. [ABSTRACT FROM AUTHOR]

The most commonly used tool for self-report of pruritus intensity is the visual analogue scale (VAS). Similar tools are the numerical rating scale (NRS) and verbal rating scale (VRS). In the present study (initiated by the International Forum for the Study of Itch) assessing reliability of these tools, 471 randomly selected patients with chronic itch (200 males, 271 females, mean age 58.44 years) recorded their pruritus intensity on VAS (100-mm line), NRS (0-10) and VRS (four-point) scales. Re-test reliability was analysed in a subgroup of 250 patients after one hour. Statistical analysis showed a high reliability and concurrent validity (r>0.8; p<0.01) for all tools. Mean values of all scales showed a high correlation. In conclusion, high reliability and concurrent validity was found for VAS, NRS and VRS. On retest, higher correlation and less missing values were observed. A training session before starting a clinical trial is recommended. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the visual analogue scale (VAS) as a method of pruritus assessment. A total of 310 subjects with pruritic dermatoses (148 Caucasian subjects and 162 Asian subjects) were recruited. The patients assessed pruritus intensity using the horizontal and vertical VAS, numeric rating scale (NRS) and verbal rating scale (VRS). All scales showed very good reproducibility (intraclass coefficient (ICC) >0.8). No significant differences were found between the horizontal and vertical VAS (5.3±2.9 vs. 5.3±3.0 points,p=0.34). Using NRS, patients rated their pruritus significantly higher than with VAS (5.7 ±2.6 points, p< 0.01). VRS showed the highest correlation with NRS (R=0.82,/><0.001), fol-lowed by horizontal (R= 0.75,p< 0.001) and vertical VAS (R=0.74,p <0.001). Based on detailed analysis following VAS categories were proposed: 0 = no pruritus, >0-<4 points = mild pruritus, ≥ 4-< 7 points=moderate pruritus, ≥ 7-< 9 points = severe pruritus, and ≥ 9 points=very severe pruritus. In conclusion, the VAS is a valuable method of pruritus measurement. [ABSTRACT FROM AUTHOR]

Chronic pruritus, which is associated with a wide variety of underlying diseases, represents a challenge in diagnostics and treatment in dermatology and general medicine. The cause of pruritus remains unknown in up to 45% of patients. In this study, 718 patients with chronic pruritus were analysed concerning lactase deficiency, demographic data, aetiology, duration and intensity of pruritus. A total of 154 patients were tested positive for lactase deficiency and 38.3% showed a significant anti-pruritic response to a lactose-free diet (minimum 4 weeks). The best results were observed in patients with pruritus of mixed or unknown origin (n = 91; 64% response). Age, sex, localization or duration had no significant influence on the anti-pruritic effect of a lactose-free diet. Lactase deficiency might be an independent causal factor in the elicitation of chronic pruritus. Thus, screening for lactase deficiency represents a rational step in the diagnostic work-up of chronic pruritus. In case of a positive test result, a lactose-free diet offers a low-cost, efficient and specific therapy in patients with chronic pruritus. [ABSTRACT FROM AUTHOR]

Pruritus is an unpleasant sensation that leads to scratching. In addition to several diseases, the administration of drugs may induce pruritus. It is estimated that pruritus accounts for approximately 5% of all skin adverse reactions after drug intake. However, to date there has been no systematic review of the natural course and possible underlying mechanisms of drug-induced pruritus. For example, no clear distinction has been made between acute or chronic (lasting more than 6 weeks) forms of pruritus. This review presents a systematic categorization of the different forms of drug-induced pruritus, with special emphasis on a therapeutic approach to this side-effect. [ABSTRACT FROM AUTHOR]

Chronic pruritus is difficult to treat and requires the evaluation of new therapeutic modalities. We initiated an open-labelled, two-arm prospective, proof-of-concept study applying two selective serotonin re-uptake inhibitors on a long-term basis. Paroxetine and fluvoxamine were tested in a total of 72 pruritic patients (27 men, 45 women, age range 28-88 years, mean age 59.2 years). The reduction in pruritus was evaluated by analysis of visual analogue scores and determination of the maximal antipruritic effect (maximal percentual reduction in pruritus). Forty-nine of 72 patients (68.0%) experienced a weak (n=9), good (n= 16) or very good (n =24) antipruritic effect. Statistical analysis proved the efficacy of paroxetine and fluvoxamine with no significant difference. The best response was observed in patients with pruritus due to atopic dermatitis, systemic lymphoma and solid carcinoma. Chronic scratch lesions healed completely in 14/31 patients and partially in 17/31 patients. Adverse drug effects were observed in 70.8% of patients, resulting in discontinuation of treatment in 18 patients. These results support previous reports of high antipruritic potency of selective serotonin re-uptake inhibitors, which are a good alternative treatment modality in chronic pruritus. This should be confirmed in future double-blind studies. [ABSTRACT FROM AUTHOR]

Chronic pruritus is a symptom of many diseases, with studies pending investigating its prevalence or incidence. The aim of this study was to describe the characteristics of the underlying diseases in a large number of patients. A total of 263 patients (110 men, 153 women; age range 8-95 years; mean 55.9 years) were included in the study. The following data were collected from patients presenting over a 3-year period: gender, age, history, skin lesions, laboratory, histological and radiological investigations. An underlying dermatosis was identified in 41.8% of patients, a systemic disease including unidentified neoplasms in 13.3% and a neurological disorder in 0.4%. No disease was found in 44.5% of patients. Among the patients in whom no disease was found, 55.6% of the, mainly elderly, patients had an accumulation of many co-factors, suggesting an own subgroup with multifactorial origin for the pruritus. The distribution and type of secondary scratch lesions gave no clue as to the underlying disease. In conclusion, patients with chronic pruritus present a inhomgeneous collective with different underlying diseases, including malignancy, necessitating thorough investigation. [ABSTRACT FROM AUTHOR]

Chronic itch is a common and distressing symptom that arises from a variety of skin conditions and systemic diseases. Despite this, there is no clinically based classification of pruritic diseases to assist in the diagnosis and cost-effective medical care of patients with pruritus. The proposed classification focuses on clinical signs and distinguishes between diseases with and without primary or secondary skin lesions. Three groups of conditions are proposed: pruritus on diseased (inflamed) skin (group I), pruritus on non-diseased (non-inflamed) skin (group II), and pruritus presenting with severe chronic secondary scratch lesions, such as prurigo nodularis (group lII). The next part classifies the underlying diseases according to different categories: dermatological diseases, systemic diseases including diseases of pregnancy and drug-induced pruritus, neurological and psychiatric diseases. In some patients more than one cause may account for pruritus (category "mixed") while in others no underlying disease can be identified (category "others"). This is the first version of a clinical classification worked out by the members of the international Forum for the Study of itch. it is intended to serve as a diagnostic route for better evaluation of patients with chronic pruritus and aims to improve patients' care. [ABSTRACT FROM AUTHOR]