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NCT Number: NCT04711044

Investigation of a New Human Model for Itch

This third sub-project aims to evaluate the interaction between the TRPM8 receptor and pruritus by studying the anti-pruritic effect of TPRM8-agonist L-menthol on histaminergic and non-histaminergic itch induced using three different pruritogens: histamine, cowhage and papain.

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Key information

Conditions

Itch Pathological Conditions, Signs and Symptoms Pruritus Signs and Symptoms Skin Diseases Skin Manifestations Skin and Connective Tissue Diseases

Age range

18 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Aalborg University

Aalborg, North Denmark, 9229, Denmark

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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 addictive drugs
  • Previous or current history of neurological, dermatological, immunological musculoskeletal, cardiac disorder or mental illnesses that may affect the results (e.g. neuropathy, muscular pain in the upper extremities, etc.).
  • Lack of ability to cooperate
  • Current use of medications that may affect the trial such as antihistamines, antipsychotics and pain killers, as well as systemic or topical steroids.
  • Skin diseases
  • Moles, scars or tattoos in the area to be treated or tested.
  • Hypersensitivity to papaya and mango fruit, cashew nuts, rubber latex
  • Consumption of alcohol or painkillers 24 hours before the study days and between these
  • Acute or chronic pain
  • Participation in other trials within 1 week of study entry (4 weeks in the case of pharmaceutical trials)

Treatment and study plan

Papain

Other

Papain will be applied using cowhage spicules inactivated by heat

Histamine

Other

To deliver histamine, standard allergy skin prick test (SPT) lancets are applied

Cowhage

Other

Cowhage spicules are 1-2 mm in length and have a diameter of 1-3 μm. The spicules are inserted by gently rubbing 30-35 spicules into a 1 cm diameter skin area.

L-menthol

Other

A 1 mL aliquot is dispensed onto a 2,5 × 2,5 cm cotton pad and placed on a 6 × 6 cm sheet of medical tape.

Primary outcomes

  1. Measuring itch intensity by computerized Visual Analog Scale Scoring

    Time frame: For 15 minutes

    We will ask the subjects to rate the sensation of itch on a 100 mm VAS scale ranging from 0 to 100 where 0 indicates "no itch" and 100 indicates "worst itch imaginable

  2. Measuring pain intensity by computerized Visual Analog Scale Scoring

    Time frame: For 15 minutes

    We will ask the subjects to rate the sensation of pain on a 100 mm VAS scale ranging from 0 to 100 where 0 indicates "no pain" and 100 indicates "worst pain imaginable".

  3. Superficial blood perfusion measurement

    Time frame: After 15 minutes

    Superficial blood perfusion is measured by a Speckle contrast imager

  4. Measuring Alloknesis

    Time frame: 15 minutes

    Alloknesis is measured by using mildly pruritic, non-painful von Frey nylon filaments of a predetermined intensity (generally 5-30 milliNewton of force).

Secondary outcomes

  1. Measurement of Cold Detection Thresholds (CDT)

    Time frame: 15 minutes

    The tests for thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.

  2. Measurement of Cold PainThresholds (CPT)

    Time frame: 15 minutes

    The tests for thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.

  3. Measurement of Heat Pain Thresholds (HPT)

    Time frame: 15 minutes

    The tests for thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.

  4. Measurement of Warm Detection Thresholds (WDT)

    Time frame: 15 minutes

    The tests for thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.

  5. Measurement of Pain to Supra-threshold Heat Stimuli

    Time frame: 15 minutes

    The tests for thermal sensation will all be conducted using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device.

  6. Measurement of Mechanical Pain Thresholds (MPT)

    Time frame: 15 minutes

    This test is conducted using a pin-prick set.

  7. Measurement of Mechanical Pain Sensitivity (MPS)

    Time frame: 15 minutes

    This test is conducted using a pin-prick set.

  8. Touch Pleasantness (TP)

    Time frame: 15 minutes

    Pleasant touch sensation measured using a standardized sensory brush

Sponsors and collaborators

Lead sponsor

Aalborg University

Other

Registry information

Official study title

Characterization of New Human Models of Non-histaminergic Itch and Their Interaction With the TRPM8 Receptor

Important dates

Study start
2021
Primary completion
2021
Study completion
2021
First posted
Jan 15, 2021
Registry last updated
Jul 9, 2021

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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