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NCT Number: NCT04858360

Inhibition of Non-histaminergic Pruritus Applied Using 3 Different Pruritogens

With this experiment, we want to use to investigate whether repeated application of EMLA cream as a tool to modulate non-histaminergic itching, which is produced using small needles from the plant mucuna pruriens (it is known that antihistamine does not attenuate this form of itch) and we want to compare the effect of short (1 hour) and prolonged (3 hours) application of EMLA. The sub-project takes place in 3 sessions over a period of 3 consecutive days (24 hours apart). All sessions will be identical.

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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, 9220, 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 drugs
  • Previous or current neurologic, musculoskeletal 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 antihistamine medications or pain killers.
  • Skin diseases
  • Hypersensitivity to papaya and mango fruit, cashew nuts and 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)
  • Known history of anaphylactic shock, or local allergy (contact dermatitis) to lidocaine, prilocaine or other local anaesthetics of the amide type.

Treatment and study plan

Emla 1 hour

Drug

At the start of each session, the middle forearms of the subject will each be divided into two squared areas (4x4 cm). On each arm, the two areas will be located 4 cm apart. Then one area will be pre-treated with cutaneous 2.5% lidocaine/2.5% prilocaine cream (EMLA cream) for 1 hour.

EMLA 3 hours

Drug

At the start of each session, the middle forearms of the subject will each be divided into two squared areas (4x4 cm). On each arm, the two areas will be located 4 cm apart. Then one area will be pre-treated with cutaneous 2.5% lidocaine/2.5% prilocaine cream (EMLA cream) for 3 hours.

Vehicle cream for 1 hour

Other

At the start of each session, the middle forearms of the subject will each be divided into two squared areas (4x4 cm). On each arm, the two areas will be located 4 cm apart. Then two area will be pre-treated with a vehicle cream for 1 h.

Vehicle cream for 3 hours

Other

At the start of each session, the middle forearms of the subject will each be divided into two squared areas (4x4 cm). On each arm, the two areas will be located 4 cm apart. Then two area will be pre-treated with a vehicle cream for 3 h.

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.

Primary outcomes

  1. Measuring itch intensity by computerized Visual Analog Scale Scoring

    Time frame: For 9 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 9 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 1 hour

    Superficial blood perfusion is measured by a Speckle contrast imager

  4. Superficial blood perfusion measurement

    Time frame: After 3 hours

    Superficial blood perfusion is measured by a Speckle contrast imager

  5. Superficial blood perfusion measurement

    Time frame: 10 min after cowhage application

    Superficial blood perfusion is measured by a Speckle contrast imager

  6. Measuring Alloknesis

    Time frame: After 1 hour

    Alloknesis sensation is measured using a standardized sensory brush exerting a force of 200 to 400 mN.

  7. Measuring Alloknesis

    Time frame: After 3 hours

    Alloknesis sensation is measured using a standardized sensory brush exerting a force of 200 to 400 mN.

  8. Measuring Alloknesis

    Time frame: 10 min after cowhage application

    Alloknesis sensation is measured using a standardized sensory brush exerting a force of 200 to 400 mN.

  9. Measuring Hyperknesis

    Time frame: After 1 hour

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

  10. Measuring Hyperknesis

    Time frame: After 3 hours

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

  11. Measuring Hyperknesis

    Time frame: 10 min after cowhage application

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

Secondary outcomes

  1. Measuring Erythema

    Time frame: After 1 hour

    The onset of erythema is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).

  2. Measuring Erythema

    Time frame: After 3 hours

    The onset of erythema is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).

  3. Measuring Erythema

    Time frame: 10 min after cowhage application

    The onset of erythema is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).

  4. Measuring Skin Pigmentation

    Time frame: After 1 hour

    The onset of skin pigmentation is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).

  5. Measuring Skin Pigmentation

    Time frame: After 3 hours

    The onset of skin pigmentation is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).

  6. Measuring Skin Pigmentation

    Time frame: 10 min after cowhage application

    The onset of skin pigmentation is measured with a spectrometer (ColorMeter, DSM II; Cortex Technology, Hadsund, Denmark).

Sponsors and collaborators

Lead sponsor

Aalborg University

Other

Registry information

Official study title

Evaluation of the Effect of Repeated Administration of Topical Local Anaesthetic Mixture of Lidocaine and Prilocaine (EMLA) in a Model of Non-histaminergic Itch Induced by Cowhage.

Important dates

Study start
2021
Primary completion
2022
Study completion
2022
First posted
Apr 26, 2021
Registry last updated
Jan 18, 2023

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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