Psychogenic and Neurogenic Components in Patients With Psychogenic or Neuropathic Pruritus

Study Overview
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Brief Summary
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Scientific research on pruritus is in intensive development, with significant advances in understanding its pathophysiology. The causes of pruritus are very huge; they can be classified into different categories; we can find dermatological causes, systemic causes, neuropathic or neurological causes, psychogenic or even idiopathic causes. The diagnosis of psychogenic pruritus is often over stated, when no cause is found; therefore, it is important to see what is really relieving from psychic so as not to over-diagnose and adopt a therapy more in line with the real problem of the patient. In daily practice, it seems to have a tendency to separate psychogenic and neurogenic etiologies in the diagnosis of neuropathic or psychogenic pruritus. In the case of patients with psychogenic pruritus and neuropathic pruritus, no study has attempted to study the respective part of psychogenic and neurogenic components. Consequently, it would therefore be interesting to assess the areas of superposition and distinction of neuropathic and psychogenic pruritus. The aim of this pilot study is to assess the psychogenic and neurogenic components of psychogenic pruritus and neuropathic pruritus in order to improve understanding of the mechanism and therefore their management. The main objective of this study is to highlight the differences and the potential common characteristics between psychogenic and neuropathic pruritus in order to improve the differential diagnosis between these two pathologies. The secondary objective of this study is to describe the psychogenic and neurogenic characteristics of psychogenic and neuropathic pruritus.

Detailed Description
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PruriNeuro : Non-interventional single-center prospective study organized and practiced on humans for the development of medical knowledge, in which the data are obtained by validated questionnaires. The duration of participation is estimated at 1 hour. Questionnaires used : Critères diagnostiques du prurit psychogène (Diagnosis criteria of functional itch disorder or psychogenic pruritus, from the French psychodermatology group) NP5 questionnaire Questionnaire de Brest HADS TAS-20 DN4i

Official Title
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Psychogenic and Neurogenic Components in Patients With Psychogenic or Neuropathic Pruritus : PRURINEURO, a Pilot Study

Conditions
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Pruritus, Psychogenic Skin Disease, Neuropathic Pain, Itch

Intervention / Treatment
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* Other: Questionnaires


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Major (> 18 years old) Diagnosis of psychogenic pruritus or neuropathic pruritus made in consultation, in day hospital or in hospital, within the dermatology department at the CHRU de Brest Able to understand and agree to sign the information and non-opposition notice No opposition of the patient Exclusion Criteria: Patient under legal protection (guardianship, curatorship) Minor (<18 years old) Acute or chronic condition which could limit the patient's ability to the study's participation Inability to understand and sign the information and non-opposition notice Refusal to give no opposition

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with Psychogenic pruritus<br> | Other: Questionnaires<br>* Evaluation of the Psychogenic and Neurogenic Components using questionnaires<br>|
| Patients with Neuropathic Pruritus<br> | Other: Questionnaires<br>* Evaluation of the Psychogenic and Neurogenic Components using questionnaires<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Questionnaire de Brest | Qualitative assessment of pruritus, specifying the chronology, location, intensity, characteristics and effect on daily activities of the itching induced by pruritus | at the enrollment | 
| HADS (Hospital Anxiety and Depression Scale) | Total score for Depression or Anxiety 0-7 = Normal 8-10 = Borderline abnormal (borderline case) 11-21 = Abnormal (case) | at the enrollment | 
| NP5 | A score of two criteria out of five is optimal to discriminate Neuropathic pruritus (NP) from Non-NP | at the enrollment | 
| TAS-20 | The TAS-20 is a self-report scale that is comprised of 20 items. Items are rated using a 5-point Likert scale whereby 1 = strongly disagree and 5 = strongly agree. There are 5 items that are negatively keyed (items 4, 5, 10, 18 and 19). The total alexithymia score is the sum of responses to all 20 items, while the score for each subscale factor is the sum of the responses to that subscale. The TAS-20 uses cutoff scoring: equal to or less than 51 = non-alexithymia, equal to or greater than 61 = alexithymia. Scores of 52 to 60 = possible alexithymia. | at the enrollment | 
| DN4i | score equal to or greater than 3 : in favor of neuropathic pruritus | at the enrollment | 
| Diagnosis criteria of functional itch disorder or psychogenic pruritus, from the French psychodermatology group | three compulsory criteria; Three additional criteria from seven items should also be present | at the enrollment | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Psychogenic Pruritus, Neuropathic Pruritus, Psychogenic Component, Neurogenic Component