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Recruiting NCT07122973

Topographical Distribution of Itch and Pain Receptors

No phase Interventional Pain Itch

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: Histamine, Cowhage, Capsaicin 8% Patch, Demo patch.
Who it may be relevant to
Registry conditions: Pain, Itch. Basic parameters: 18 years — 60 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
Denmark
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

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Official title

Pain and Itch Neuromodulation: Effects of Offset Analgesia, Placebo, and Nocebo and Topographical Distribution of Itch and Pain Receptors

Overview

The experiment consists of three experimental sessions conducted on three consecutive days. In all experimental sessions, the participant will fill in a series of questionnaires about how you perceive itch and pain, and about some traits of your personality, such as depression, anxiety and stress. In the first session, we will mark six test areas in your face (three on each side on jaw, cheek, and temple, respectively). Thent a series of measure-ments in each test area will be conducted:measurement of the blood flow in the skin and sensitivity tests to pressure, pinprick and stroke with a brush. In the second session, histamine will be applied in one side of the face. On the other side, cowhage spicules will be applied. After 10 minutes, all the tests will be conducted again. The third session will be identical to the second. However, instead of histamine and spicules, patches containing capsaicin will be applied. In the other side, we will apply patches with placebo (i.e., a non-active patch). After 20 minutes all the tests will be conducted again.

Interventions

  • Other Histamine
    To deliver histamine, standard allergy skin prick test (SPT) lancets are applied
  • Other Cowhage
    The spicules will be manually inserted. Approximately 30-35 spicules are gently rubbed into a 1 cm diameter skin area on the forearm/face
  • Other Capsaicin 8% Patch
    Capsaicin patches (dosage form: transdermal patch 8% Qutenza, Astellas) will be applied on 3 squared areas in the face.
  • Other Demo patch
    Placebo patch (demo patch, containing the same formulation as the active treatment with the exception of capsaicin) will be applied on 3 squared areas in the face.

Primary outcome measures

  • Measuring pain by computerized Visual Analog Scale Scoring [Time frame: Baseline]
  • Measuring itch by computerized Visual Analog Scale Scoring [Time frame: Baseline]
  • Measuring pain by computerized Visual Analog Scale Scoring [Time frame: Immediately after the intervention]
  • Measuring itch by computerized Visual Analog Scale Scoring [Time frame: Immediately after the intervention]
Secondary outcome measures (12)
  • Superficial blood perfusion [Time frame: Baseline]
  • Superficial blood perfusion [Time frame: Immediately after the intervention]
  • Alloknesis [Time frame: Baseline]
  • Alloknesis [Time frame: Immediately after the intervention]
  • Mechanically evoked itch (MEI) [Time frame: Baseline]
  • Mechanically evoked itch (MEI) [Time frame: Immediately after the intervention]
  • Mechanical Pain Thresholds (MPT) [Time frame: Baseline]
  • Mechanical Pain Thresholds (MPT) [Time frame: Immediately after the intervention]
  • Mechanical Pain Sensitivity (MPS) [Time frame: Baseline]
  • Mechanical Pain Sensitivity (MPS) [Time frame: Immediately after the intervention]
  • Cold Detection Thresholds (CDT) [Time frame: Baseline]
  • Cold Detection Thresholds (CDT) [Time frame: Immediately after the intervention]

Eligibility criteria

Inclusion criteria

  • Healthy men and women
  • 18-60 years
  • Speak and understand English

Exclusion criteria

  • Pregnancy or lactation
  • Drug addiction defined as any use of cannabis, opioids, or other drugs
  • Previous or current history of neurological, immunological, musculoskeletal, cardiac disorder or psychiatric diagnoses that may affect the results (e.g., neuropathy, muscular pain in the upper extremities, anxiety, depression, schizophrenia, etc.)
  • Moles, wounds, scars, or tattoos in the area to be treated or tested
  • Current use of medications that may affect the trial such as antihistamines and pain killers
  • Skin diseases
  • Consumption of alcohol or painkillers 24 hours before the study days and between these
  • Acute or chronic pain and itch
  • Participation in other trials within 1 week of study entry (4 weeks in the case of pharmaceutical studies)
  • Contraindications to capsaicin, including intolerance to chili or burns or wounds at the application site
  • The subject is assessed as unable to engage in the necessary cooperation required by the study

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation
N/A
Model
Single group
Masking
Open label
Primary purpose
Basic science

Study locations

Denmark · 1 center
  • Aalborg University — Gistrup

Identifiers

NCT: NCT07122973 · N-20250017 Project 4

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗