europhysiological and morphological studies on endogenous pruritic inhibition by thermal pain (Diffuse Pruritic Inhibitory Control, DPIC) in chronic pruritus patients and healthy controls

• Conditions: L29.8; Other pruritus

• Registration Number: DRKS00011008
• Lead Sponsor: Kompetenzzentrum chronischer Pruritus (KCP) und Klinik für Hautkrankheiten Universitätsklinikum Münster

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Study Start: 2016-09-09
• Study Completion: 2020-10-15
• Last Update Posted: 19 August 2024

Recruitment & Eligibility

• Status: Complete
• Sex: All
• Target Recruitment: 200

Inclusion Criteria

Patients with chronic pruritus and matched (age and gender) healthy controls

Exclusion Criteria

- maximal pruritus intensity <3 (VAS, 0-10) in the first two minutes after cowhage or histamine application
- skin lesions in the testing site (e.g. erosions, infection)
- neurological or severe psychiatric comorbidities according to the medical history
- skin type = III (Fitzpatrick; Mediterranean and darker skin types are excluded due tot he lack of data in healthy controls)
- allergy against the study substances
- disease that prevents the participation in the study
- use of medication that influences the perception of pruritus up to1 week prior to study start (e.g. antihistamines, pregabaline/gabapentine, opioids)
- use of urea, polidocanol, capsaicin, topical steroids, topical keratolytica, exfoliatives, self-tanners, topical or systemic antihistamines, anticonvulsivants, sedatives up to 1 week prior to study start
- systemic steroids up to 2 weeks prior to study start
- topical or systemic immunmodulators, antidepressants, drugs against migraine up to 1 month prior to study start
- non steroidal or other non-opioid pain killers up to 2 days prior to study start
- use of cosmetics or skin care products on the study day
- pregnant or breastfeeding women

Healthy controls:
- atopy
- pruritus

Study & Design

• Study Type: observational
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Difference of the pruritus inhibition effect (duration and magnitude of pruritus reduction) by noxious heat/cold stimulation between healthy controls and chronic pruritus patients of various origins in different experimental models:<br>A) cowhage (activation of mechano-sensitive C-fibers)<br>B) histamine (activation of mechano-insensitive C-fibers)<br>C) negative control NaCl: study participants receive saline instead of cowhage or histamine<br>

Secondary Outcome Measures

Name	Time	Method
a) Correlation between QST parameters and the pruritus inhibitory effect by thermal pain<br>b) Delta of QST parameters before and after stimulation with Bite Away ®<br>c) Correlation between the intraepidermal nerve fiber density and the magnitude of pruritus inhibition by thermal pain<br>d) Correlation between psychological variables (assessed by standardized questionnaires) and the magnitude of pruritus inhibition by thermal pain<br>