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Investigation of the Effects of Sleep Fragmentation on Itch and Pain Sensitivity

Primary Purpose

Histamine, Cowhage, Sleep Fragmentation

Status
Not yet recruiting
Phase
Not Applicable
Locations
Study Type
Interventional
Intervention
Histamine
Cowhage
Sponsored by
Aalborg University
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional basic science trial for Histamine

Eligibility Criteria

18 Years - 60 Years (Adult)All SexesAccepts Healthy Volunteers

Inclusion Criteria: Healthy men and women 18-60 years Speak and understand English Access to a smartphone during the experimental nights Exclusion Criteria: Pregnancy or lactation Drug addiction defined as any use of cannabis, opioids, or other drugs Previous or current history of neurological, dermatological, immunological musculoskeletal, cardiac disorder or mental illnesses (psychiatric diagnosis) 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) Lack of ability to cooperate

Sites / Locations

    Arms of the Study

    Arm 1

    Arm Type

    Experimental

    Arm Label

    Sleep fragmentation

    Arm Description

    This subproject will be conducted in two sessions separated by three nights of sleep fragmentation. Each session will last approximately 2 hours. At the beginning of the first visit and after the last visit, 9 ml of blood will be drawn, and plasma will be isolated. After plasma isolation, the CRP concentration will be analyzed. In each forearm of the participant, a 4x4 cm area will be selected as Area of Interest (AOI). In these selected areas, itch will be induced in both sessions using histamine and cowhage and several tests will be conducted.

    Outcomes

    Primary Outcome Measures

    Assessment of itch
    Immediately following the itch provocations, participants will be instructed to rate the itch intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no itch' and 100 'worst itch imaginable'.
    Assessment of itch
    Immediately following the itch provocations, participants will be instructed to rate the itch intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no itch' and 100 'worst itch imaginable'.
    Assessment of pain
    Immediately following the itch provocations, participants will be instructed to rate the pain intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no pain' and 100 'worst pain imaginable'.
    Assessment of pain
    Immediately following the itch provocations, participants will be instructed to rate the pain intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no pain' and 100 'worst pain imaginable'.

    Secondary Outcome Measures

    Microvascular reactivity
    The evoked cutaneous inflammation (quantified by superficial blood perfusion) will be measured by full-field laser perfusion imaging.
    Microvascular reactivity
    The evoked cutaneous inflammation (quantified by superficial blood perfusion) will be measured by full-field laser perfusion imaging.
    Touch Pleasantness (TP)
    Pleasant touch sensation measured using a standardized sensory brush (SENSELab Brush-05, Somedic AB, Hörby, Sweden) exerting a force of 200 to 400 mN. The stimulation consists of three strokes (2 cm in length) over the treated/control areas. The strokes will be applied perpendicularly to the skin and the subject will rate the sensation induced by the brush on a NRS scale labeled "very unpleasant" and "very pleasant" at the extremity and "neutral" at the center.
    Touch Pleasantness (TP)
    Pleasant touch sensation measured using a standardized sensory brush (SENSELab Brush-05, Somedic AB, Hörby, Sweden) exerting a force of 200 to 400 mN. The stimulation consists of three strokes (2 cm in length) over the treated/control areas. The strokes will be applied perpendicularly to the skin and the subject will rate the sensation induced by the brush on a NRS scale labeled "very unpleasant" and "very pleasant" at the extremity and "neutral" at the center.
    Mechanically evoked itch (MEI), intensity approach
    MEI is measured by using mildly pruritic, non-painful von Frey nylon filaments of a predetermined intensity (generally 5-30 miliNewton of force). This stimulator is moved in intervals of 0.5 cm outside the area of itch provocation.
    Mechanically evoked itch (MEI), intensity approach
    MEI is measured by using mildly pruritic, non-painful von Frey nylon filaments of a predetermined intensity (generally 5-30 miliNewton of force). This stimulator is moved in intervals of 0.5 cm outside the area of itch provocation.
    Mechanically evoked itch, spatial approach
    The von-Frey filament that better evokes the itch sensation during the assessment of mechanically evoked itch as well as a template of soft plastic are used to map the area of hyperkinesis in the test areas (forearms)
    Mechanically evoked itch, spatial approach
    The von-Frey filament that better evokes the itch sensation during the assessment of mechanically evoked itch as well as a template of soft plastic are used to map the area of hyperkinesis in the test areas (forearms)
    Mechanical Pain Thresholds (MPT)
    This test is conducted using a pinprick set (Aalborg University, Aalborg). The set consists of 7 needles each with a diameter of 0.6 mm and different force applications: 8, 16, 32, 64, 128, 256, and 512 mN.
    Mechanical Pain Thresholds (MPT)
    This test is conducted using a pinprick set (Aalborg University, Aalborg). The set consists of 7 needles each with a diameter of 0.6 mm and different force applications: 8, 16, 32, 64, 128, 256, and 512 mN.
    Mechanical Pain Sensitivity (MPS), intensity approach
    This test is conducted with the same pinprick set used to test the MPT. Starting with the lightest, each stimulator is applied at a rate of 2 s on, 2 s off in an ascending order, and the subject will be asked to give a pain rating for each stimulus on a scale from 0-10 (where 0 indicates ''no pain'', and 10 indicates the ''worst imaginable pain'').
    Mechanical Pain Sensitivity (MPS), intensity approach
    This test is conducted with the same pinprick set used to test the MPT. Starting with the lightest, each stimulator is applied at a rate of 2 s on, 2 s off in an ascending order, and the subject will be asked to give a pain rating for each stimulus on a scale from 0-10 (where 0 indicates ''no pain'', and 10 indicates the ''worst imaginable pain'').
    Cold Detection Thresholds (CDT) and heat (HPT) detection
    Thermal cold and heat stimuli will be applied by a contact heat-evoked potential stimulator (PATHWAYS; Medoc Ltd, Ramat Yishai, Israel), placed 5 cm distal to the elbow on the right dorsal forearm
    Cold Detection Thresholds (CDT) and heat (HPT) detection
    Thermal cold and heat stimuli will be applied by a contact heat-evoked potential stimulator (PATHWAYS; Medoc Ltd, Ramat Yishai, Israel), placed 5 cm distal to the elbow on the right dorsal forearm
    Cold Detection Thresholds (CDT) and heat (HPT) pain thresholds
    Thermal cold and heat stimuli will be applied by a contact heat-evoked potential stimulator (PATHWAYS; Medoc Ltd, Ramat Yishai, Israel), placed 5 cm distal to the elbow on the right dorsal forearm
    Cold Detection Thresholds (CDT) and heat (HPT) pain thresholds
    Thermal cold and heat stimuli will be applied by a contact heat-evoked potential stimulator (PATHWAYS; Medoc Ltd, Ramat Yishai, Israel), placed 5 cm distal to the elbow on the right dorsal forearm
    Pain to Supra-threshold Heat Stimuli (STHS)
    The tests will be conducted by using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device. A thermode stimulator of 3x3 cm will be placed on the treated/placebo areas and kept in place by means of Velcro tape. The subjects will rate the pain to three suprathreshold heat pain stimuli (starting and ending at 32°C with an increase and decrease of 5°C and 3 s plateau at 50°C).
    Pain to Supra-threshold Heat Stimuli (STHS)
    The tests will be conducted by using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device. A thermode stimulator of 3x3 cm will be placed on the treated/placebo areas and kept in place by means of Velcro tape. The subjects will rate the pain to three suprathreshold heat pain stimuli (starting and ending at 32°C with an increase and decrease of 5°C and 3 s plateau at 50°C).
    Deep-tissue Pain Sensitivity Measurements
    Deep-tissue pain sensitivity will be evaluated by cuff pressure stimuli using a computer-controlled cuff algometer (Cortex Technology and Aalborg University, Denmark) including a 13-cm wide tourniquet cuff (VBM, Sulz, Germany) and an electronic visual analog scale (VAS) (Aalborg University, Denmark) for recording of the pain intensity.
    Deep-tissue Pain Sensitivity Measurements
    Deep-tissue pain sensitivity will be evaluated by cuff pressure stimuli using a computer-controlled cuff algometer (Cortex Technology and Aalborg University, Denmark) including a 13-cm wide tourniquet cuff (VBM, Sulz, Germany) and an electronic visual analog scale (VAS) (Aalborg University, Denmark) for recording of the pain intensity.
    Pressure Detection and Tolerance Threshold
    The pressure will be increased by 1 kPa/s and the subject will be instructed to rate the pain intensity continuously on the electronic VAS until the tolerance level is reached.
    Pressure Detection and Tolerance Threshold
    The pressure will be increased by 1 kPa/s and the subject will be instructed to rate the pain intensity continuously on the electronic VAS until the tolerance level is reached.
    Temporal Summation of Pain - TSP
    A total of 10 repeated mechanical pressure stimuli at the PTT level will be delivered at 0.5 Hz (1 s stimulus duration and 1 s interval between stimuli) to the lower leg. A constant pressure of 5 kPa will be applied between the individual pressure stimuli to avoid movement of the cuff. During the 10 repeated stimuli, the subject will continuously rate the pain intensity on a 10 cm continuous VAS.
    Temporal Summation of Pain - TSP
    A total of 10 repeated mechanical pressure stimuli at the PTT level will be delivered at 0.5 Hz (1 s stimulus duration and 1 s interval between stimuli) to the lower leg. A constant pressure of 5 kPa will be applied between the individual pressure stimuli to avoid movement of the cuff. During the 10 repeated stimuli, the subject will continuously rate the pain intensity on a 10 cm continuous VAS.
    Conditioned Pain Modulation - CPM
    The concept of CPM is that a tonic painful stimulus (conditioning stimulus) will inhibit pain evoked simultaneously from another site (test stimulus). The painful conditioned stimulus will be applied simultaneously with the assessment stimulus. The conditioned stimulus will be terminated right after the subject presses the stop button. CPM will be defined as the difference between stimulus during and before the conditioned pain (i.e., "during" minus "before").
    Conditioned Pain Modulation - CPM
    The concept of CPM is that a tonic painful stimulus (conditioning stimulus) will inhibit pain evoked simultaneously from another site (test stimulus). The painful conditioned stimulus will be applied simultaneously with the assessment stimulus. The conditioned stimulus will be terminated right after the subject presses the stop button. CPM will be defined as the difference between stimulus during and before the conditioned pain (i.e., "during" minus "before").
    The Itch Catastrophizing Scale
    The itch catastrophizing scale is a modified version of the pain catastrophizing scale (PCS), which is a validated questionnaire measuring pain-related thoughts and feelings
    The Itch Catastrophizing Scale
    The itch catastrophizing scale is a modified version of the pain catastrophizing scale (PCS), which is a validated questionnaire measuring pain-related thoughts and feelings
    The Pittsburg Sleep Quality Index (PSQI)
    The PSQI consists of 19 items generating seven component scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction..
    The Pittsburg Sleep Quality Index (PSQI)
    The PSQI consists of 19 items generating seven component scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction..
    The Hospital Anxiety and Depression Scale (HADS)
    The HADS consists of 14 items with two 7-item subscales measuring anxiety and depression symptoms, respectively.
    The Hospital Anxiety and Depression Scale (HADS)
    The HADS consists of 14 items with two 7-item subscales measuring anxiety and depression symptoms, respectively.
    Positive and Negative Affective Schedule
    This 20-item instrument is a psychometric self-report test to assess affect (10 items for positive affect and 10 items for negative affect) and validated for the use in adolescents and adults
    Positive and Negative Affective Schedule
    This 20-item instrument is a psychometric self-report test to assess affect (10 items for positive affect and 10 items for negative affect) and validated for the use in adolescents and adults
    Blood Sampling for C-Reactive Protein Analysis
    Whole blood samples will be collected from the antecubital vein using a vacutainer blood collection device (S-Monovette, Sarstedt) with a 21-gauge needle.
    Blood Sampling for C-Reactive Protein Analysis
    Whole blood samples will be collected from the antecubital vein using a vacutainer blood collection device (S-Monovette, Sarstedt) with a 21-gauge needle.

    Full Information

    First Posted
    October 2, 2023
    Last Updated
    October 8, 2023
    Sponsor
    Aalborg University
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    1. Study Identification

    Unique Protocol Identification Number
    NCT06081946
    Brief Title
    Investigation of the Effects of Sleep Fragmentation on Itch and Pain Sensitivity
    Official Title
    Investigation of the Effects of Sleep Provocations on Itch and Pain Sensitivity
    Study Type
    Interventional

    2. Study Status

    Record Verification Date
    October 2023
    Overall Recruitment Status
    Not yet recruiting
    Study Start Date
    December 15, 2023 (Anticipated)
    Primary Completion Date
    September 30, 2024 (Anticipated)
    Study Completion Date
    December 31, 2026 (Anticipated)

    3. Sponsor/Collaborators

    Responsible Party, by Official Title
    Principal Investigator
    Name of the Sponsor
    Aalborg University

    4. Oversight

    Studies a U.S. FDA-regulated Drug Product
    No
    Studies a U.S. FDA-regulated Device Product
    No
    Data Monitoring Committee
    Yes

    5. Study Description

    Brief Summary
    In This experiment, the investigators would like to test following hypotheses regarding the influence of sleep fragmentation on itch: To investigate similarity and differences between itch and pain by comparing the effect of sleep deprivation in them. To evaluate the inflammatory state induced by sleep fragmentation via the analysis of C-reactive protein (CRP) levels from blood samples. To correlate the anxiety and depression scores (evaluated through questionnaires) with itch and pain sensitivity and evaluate how they are affected by sleep fragmentation.
    Detailed Description
    Chronic itch affects approximately a fifth of the global population and is associated with substantial negative consequences for the affected individuals. Furthermore, there is a lack of efficient treatment options for chronic itch. Poor sleep is a common companion of itch and is often reported by patients with chronic itch. Poor sleep is often characterized by nightly awakenings and troubles falling asleep. This is a significant problem as poor sleep in general is associated with lowered quality of life. While previous research has already established the negative impact of itch on sleep, it is yet to be studied whether the opposite tendency might be true as well. Knowledge about patients with chronic pain has shown that poor sleep can increase the sensitivity to pain and inflammation, and this tendency can also be observed in healthy participants after experimental sleep provocations. Therefore, the investigators wish to investigate how sleep provocations affect markers of itch in healthy participants.

    6. Conditions and Keywords

    Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
    Histamine, Cowhage, Sleep Fragmentation

    7. Study Design

    Primary Purpose
    Basic Science
    Study Phase
    Not Applicable
    Interventional Study Model
    Single Group Assignment
    Model Description
    The participants will be instructed to wake up at three designated timepoints for three consecutive nights at home.
    Masking
    None (Open Label)
    Masking Description
    Participant will be blinded about application of pruritogens.
    Allocation
    Non-Randomized
    Enrollment
    30 (Anticipated)

    8. Arms, Groups, and Interventions

    Arm Title
    Sleep fragmentation
    Arm Type
    Experimental
    Arm Description
    This subproject will be conducted in two sessions separated by three nights of sleep fragmentation. Each session will last approximately 2 hours. At the beginning of the first visit and after the last visit, 9 ml of blood will be drawn, and plasma will be isolated. After plasma isolation, the CRP concentration will be analyzed. In each forearm of the participant, a 4x4 cm area will be selected as Area of Interest (AOI). In these selected areas, itch will be induced in both sessions using histamine and cowhage and several tests will be conducted.
    Intervention Type
    Other
    Intervention Name(s)
    Histamine
    Intervention Description
    Histaminergic itch will be evoked by a 1% histamine solution. A droplet of histamine solution will be placed on the predetermined area on the forearm, and the SPT lancet will be pierced through the histamine with 120 g of pressure for 1-2 seconds
    Intervention Type
    Other
    Intervention Name(s)
    Cowhage
    Intervention Description
    25 spicules will be inserted in the centre of the predefined skin area on the mandibular area. The spicules will be gently rubbed for 15-20 seconds in circular motion to facilitate epidermal penetration
    Primary Outcome Measure Information:
    Title
    Assessment of itch
    Description
    Immediately following the itch provocations, participants will be instructed to rate the itch intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no itch' and 100 'worst itch imaginable'.
    Time Frame
    Day 1: 1 minute after every itch inductions
    Title
    Assessment of itch
    Description
    Immediately following the itch provocations, participants will be instructed to rate the itch intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no itch' and 100 'worst itch imaginable'.
    Time Frame
    Day 2: 1 minute after every itch inductions
    Title
    Assessment of pain
    Description
    Immediately following the itch provocations, participants will be instructed to rate the pain intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no pain' and 100 'worst pain imaginable'.
    Time Frame
    Day 1: 1 minute after every itch inductions
    Title
    Assessment of pain
    Description
    Immediately following the itch provocations, participants will be instructed to rate the pain intensity for 10 minutes using a digital visual analogue scale (VAS; eVAS Software: Aalborg, University, Denmark), on a tablet. The scale will be measured from 0 to 100, where 0 represents 'no pain' and 100 'worst pain imaginable'.
    Time Frame
    Day 2: 1 minute after every itch inductions
    Secondary Outcome Measure Information:
    Title
    Microvascular reactivity
    Description
    The evoked cutaneous inflammation (quantified by superficial blood perfusion) will be measured by full-field laser perfusion imaging.
    Time Frame
    Day 1: 10 minutes after every itch inductions
    Title
    Microvascular reactivity
    Description
    The evoked cutaneous inflammation (quantified by superficial blood perfusion) will be measured by full-field laser perfusion imaging.
    Time Frame
    Day 2: 10 minutes after every itch inductions
    Title
    Touch Pleasantness (TP)
    Description
    Pleasant touch sensation measured using a standardized sensory brush (SENSELab Brush-05, Somedic AB, Hörby, Sweden) exerting a force of 200 to 400 mN. The stimulation consists of three strokes (2 cm in length) over the treated/control areas. The strokes will be applied perpendicularly to the skin and the subject will rate the sensation induced by the brush on a NRS scale labeled "very unpleasant" and "very pleasant" at the extremity and "neutral" at the center.
    Time Frame
    Day 1: 10 minutes after every itch inductions
    Title
    Touch Pleasantness (TP)
    Description
    Pleasant touch sensation measured using a standardized sensory brush (SENSELab Brush-05, Somedic AB, Hörby, Sweden) exerting a force of 200 to 400 mN. The stimulation consists of three strokes (2 cm in length) over the treated/control areas. The strokes will be applied perpendicularly to the skin and the subject will rate the sensation induced by the brush on a NRS scale labeled "very unpleasant" and "very pleasant" at the extremity and "neutral" at the center.
    Time Frame
    Day 2: 10 minutes after every itch inductions
    Title
    Mechanically evoked itch (MEI), intensity approach
    Description
    MEI is measured by using mildly pruritic, non-painful von Frey nylon filaments of a predetermined intensity (generally 5-30 miliNewton of force). This stimulator is moved in intervals of 0.5 cm outside the area of itch provocation.
    Time Frame
    Day 1: 10 minutes after every itch inductions
    Title
    Mechanically evoked itch (MEI), intensity approach
    Description
    MEI is measured by using mildly pruritic, non-painful von Frey nylon filaments of a predetermined intensity (generally 5-30 miliNewton of force). This stimulator is moved in intervals of 0.5 cm outside the area of itch provocation.
    Time Frame
    Day 2: 10 minutes after every itch inductions
    Title
    Mechanically evoked itch, spatial approach
    Description
    The von-Frey filament that better evokes the itch sensation during the assessment of mechanically evoked itch as well as a template of soft plastic are used to map the area of hyperkinesis in the test areas (forearms)
    Time Frame
    Day 1: 10 minutes after every itch inductions
    Title
    Mechanically evoked itch, spatial approach
    Description
    The von-Frey filament that better evokes the itch sensation during the assessment of mechanically evoked itch as well as a template of soft plastic are used to map the area of hyperkinesis in the test areas (forearms)
    Time Frame
    Day 2: 10 minutes after every itch inductions
    Title
    Mechanical Pain Thresholds (MPT)
    Description
    This test is conducted using a pinprick set (Aalborg University, Aalborg). The set consists of 7 needles each with a diameter of 0.6 mm and different force applications: 8, 16, 32, 64, 128, 256, and 512 mN.
    Time Frame
    Day 1: 10 minutes after every itch inductions
    Title
    Mechanical Pain Thresholds (MPT)
    Description
    This test is conducted using a pinprick set (Aalborg University, Aalborg). The set consists of 7 needles each with a diameter of 0.6 mm and different force applications: 8, 16, 32, 64, 128, 256, and 512 mN.
    Time Frame
    Day 2: 10 minutes after every itch inductions
    Title
    Mechanical Pain Sensitivity (MPS), intensity approach
    Description
    This test is conducted with the same pinprick set used to test the MPT. Starting with the lightest, each stimulator is applied at a rate of 2 s on, 2 s off in an ascending order, and the subject will be asked to give a pain rating for each stimulus on a scale from 0-10 (where 0 indicates ''no pain'', and 10 indicates the ''worst imaginable pain'').
    Time Frame
    Day 1: 10 minutes after every itch inductions
    Title
    Mechanical Pain Sensitivity (MPS), intensity approach
    Description
    This test is conducted with the same pinprick set used to test the MPT. Starting with the lightest, each stimulator is applied at a rate of 2 s on, 2 s off in an ascending order, and the subject will be asked to give a pain rating for each stimulus on a scale from 0-10 (where 0 indicates ''no pain'', and 10 indicates the ''worst imaginable pain'').
    Time Frame
    Day 2: 10 minutes after every itch inductions
    Title
    Cold Detection Thresholds (CDT) and heat (HPT) detection
    Description
    Thermal cold and heat stimuli will be applied by a contact heat-evoked potential stimulator (PATHWAYS; Medoc Ltd, Ramat Yishai, Israel), placed 5 cm distal to the elbow on the right dorsal forearm
    Time Frame
    Day 1: 10 minutes after every itch inductions
    Title
    Cold Detection Thresholds (CDT) and heat (HPT) detection
    Description
    Thermal cold and heat stimuli will be applied by a contact heat-evoked potential stimulator (PATHWAYS; Medoc Ltd, Ramat Yishai, Israel), placed 5 cm distal to the elbow on the right dorsal forearm
    Time Frame
    Day 2: 10 minutes after every itch inductions
    Title
    Cold Detection Thresholds (CDT) and heat (HPT) pain thresholds
    Description
    Thermal cold and heat stimuli will be applied by a contact heat-evoked potential stimulator (PATHWAYS; Medoc Ltd, Ramat Yishai, Israel), placed 5 cm distal to the elbow on the right dorsal forearm
    Time Frame
    Day 1: 10 minutes after every itch inductions
    Title
    Cold Detection Thresholds (CDT) and heat (HPT) pain thresholds
    Description
    Thermal cold and heat stimuli will be applied by a contact heat-evoked potential stimulator (PATHWAYS; Medoc Ltd, Ramat Yishai, Israel), placed 5 cm distal to the elbow on the right dorsal forearm
    Time Frame
    Day 2: 10 minutes after every itch inductions
    Title
    Pain to Supra-threshold Heat Stimuli (STHS)
    Description
    The tests will be conducted by using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device. A thermode stimulator of 3x3 cm will be placed on the treated/placebo areas and kept in place by means of Velcro tape. The subjects will rate the pain to three suprathreshold heat pain stimuli (starting and ending at 32°C with an increase and decrease of 5°C and 3 s plateau at 50°C).
    Time Frame
    Day 1: 10 minutes after every itch inductions
    Title
    Pain to Supra-threshold Heat Stimuli (STHS)
    Description
    The tests will be conducted by using a PATHWAY ATS (Medoc Ltd, Israel) thermal sensory testing device. A thermode stimulator of 3x3 cm will be placed on the treated/placebo areas and kept in place by means of Velcro tape. The subjects will rate the pain to three suprathreshold heat pain stimuli (starting and ending at 32°C with an increase and decrease of 5°C and 3 s plateau at 50°C).
    Time Frame
    Day 2: 10 minutes after every itch inductions
    Title
    Deep-tissue Pain Sensitivity Measurements
    Description
    Deep-tissue pain sensitivity will be evaluated by cuff pressure stimuli using a computer-controlled cuff algometer (Cortex Technology and Aalborg University, Denmark) including a 13-cm wide tourniquet cuff (VBM, Sulz, Germany) and an electronic visual analog scale (VAS) (Aalborg University, Denmark) for recording of the pain intensity.
    Time Frame
    Day 1: 10 minutes after every itch inductions
    Title
    Deep-tissue Pain Sensitivity Measurements
    Description
    Deep-tissue pain sensitivity will be evaluated by cuff pressure stimuli using a computer-controlled cuff algometer (Cortex Technology and Aalborg University, Denmark) including a 13-cm wide tourniquet cuff (VBM, Sulz, Germany) and an electronic visual analog scale (VAS) (Aalborg University, Denmark) for recording of the pain intensity.
    Time Frame
    Day 2: 10 minutes after every itch inductions
    Title
    Pressure Detection and Tolerance Threshold
    Description
    The pressure will be increased by 1 kPa/s and the subject will be instructed to rate the pain intensity continuously on the electronic VAS until the tolerance level is reached.
    Time Frame
    Day 1: 10 minutes after every itch inductions
    Title
    Pressure Detection and Tolerance Threshold
    Description
    The pressure will be increased by 1 kPa/s and the subject will be instructed to rate the pain intensity continuously on the electronic VAS until the tolerance level is reached.
    Time Frame
    Day 2: 10 minutes after every itch inductions
    Title
    Temporal Summation of Pain - TSP
    Description
    A total of 10 repeated mechanical pressure stimuli at the PTT level will be delivered at 0.5 Hz (1 s stimulus duration and 1 s interval between stimuli) to the lower leg. A constant pressure of 5 kPa will be applied between the individual pressure stimuli to avoid movement of the cuff. During the 10 repeated stimuli, the subject will continuously rate the pain intensity on a 10 cm continuous VAS.
    Time Frame
    Day 1: 10 minutes after every itch inductions
    Title
    Temporal Summation of Pain - TSP
    Description
    A total of 10 repeated mechanical pressure stimuli at the PTT level will be delivered at 0.5 Hz (1 s stimulus duration and 1 s interval between stimuli) to the lower leg. A constant pressure of 5 kPa will be applied between the individual pressure stimuli to avoid movement of the cuff. During the 10 repeated stimuli, the subject will continuously rate the pain intensity on a 10 cm continuous VAS.
    Time Frame
    Day 2: 10 minutes after every itch inductions
    Title
    Conditioned Pain Modulation - CPM
    Description
    The concept of CPM is that a tonic painful stimulus (conditioning stimulus) will inhibit pain evoked simultaneously from another site (test stimulus). The painful conditioned stimulus will be applied simultaneously with the assessment stimulus. The conditioned stimulus will be terminated right after the subject presses the stop button. CPM will be defined as the difference between stimulus during and before the conditioned pain (i.e., "during" minus "before").
    Time Frame
    Day 1: 10 minutes after every itch inductions
    Title
    Conditioned Pain Modulation - CPM
    Description
    The concept of CPM is that a tonic painful stimulus (conditioning stimulus) will inhibit pain evoked simultaneously from another site (test stimulus). The painful conditioned stimulus will be applied simultaneously with the assessment stimulus. The conditioned stimulus will be terminated right after the subject presses the stop button. CPM will be defined as the difference between stimulus during and before the conditioned pain (i.e., "during" minus "before").
    Time Frame
    Day 2: 10 minutes after every itch inductions
    Title
    The Itch Catastrophizing Scale
    Description
    The itch catastrophizing scale is a modified version of the pain catastrophizing scale (PCS), which is a validated questionnaire measuring pain-related thoughts and feelings
    Time Frame
    Day 1
    Title
    The Itch Catastrophizing Scale
    Description
    The itch catastrophizing scale is a modified version of the pain catastrophizing scale (PCS), which is a validated questionnaire measuring pain-related thoughts and feelings
    Time Frame
    Day 2
    Title
    The Pittsburg Sleep Quality Index (PSQI)
    Description
    The PSQI consists of 19 items generating seven component scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction..
    Time Frame
    Day 1
    Title
    The Pittsburg Sleep Quality Index (PSQI)
    Description
    The PSQI consists of 19 items generating seven component scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction..
    Time Frame
    Day 2
    Title
    The Hospital Anxiety and Depression Scale (HADS)
    Description
    The HADS consists of 14 items with two 7-item subscales measuring anxiety and depression symptoms, respectively.
    Time Frame
    Day 1
    Title
    The Hospital Anxiety and Depression Scale (HADS)
    Description
    The HADS consists of 14 items with two 7-item subscales measuring anxiety and depression symptoms, respectively.
    Time Frame
    Day 2
    Title
    Positive and Negative Affective Schedule
    Description
    This 20-item instrument is a psychometric self-report test to assess affect (10 items for positive affect and 10 items for negative affect) and validated for the use in adolescents and adults
    Time Frame
    Day 1
    Title
    Positive and Negative Affective Schedule
    Description
    This 20-item instrument is a psychometric self-report test to assess affect (10 items for positive affect and 10 items for negative affect) and validated for the use in adolescents and adults
    Time Frame
    Day 2
    Title
    Blood Sampling for C-Reactive Protein Analysis
    Description
    Whole blood samples will be collected from the antecubital vein using a vacutainer blood collection device (S-Monovette, Sarstedt) with a 21-gauge needle.
    Time Frame
    Day 1
    Title
    Blood Sampling for C-Reactive Protein Analysis
    Description
    Whole blood samples will be collected from the antecubital vein using a vacutainer blood collection device (S-Monovette, Sarstedt) with a 21-gauge needle.
    Time Frame
    Day 2

    10. Eligibility

    Sex
    All
    Minimum Age & Unit of Time
    18 Years
    Maximum Age & Unit of Time
    60 Years
    Accepts Healthy Volunteers
    Accepts Healthy Volunteers
    Eligibility Criteria
    Inclusion Criteria: Healthy men and women 18-60 years Speak and understand English Access to a smartphone during the experimental nights Exclusion Criteria: Pregnancy or lactation Drug addiction defined as any use of cannabis, opioids, or other drugs Previous or current history of neurological, dermatological, immunological musculoskeletal, cardiac disorder or mental illnesses (psychiatric diagnosis) 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) Lack of ability to cooperate
    Central Contact Person:
    First Name & Middle Initial & Last Name or Official Title & Degree
    kristian Kjær-Staal Petersen
    Phone
    31697510
    Email
    KKP@hst.aau.dk
    First Name & Middle Initial & Last Name or Official Title & Degree
    Silvia Lo Vecchio
    Phone
    +4521397785
    Email
    slv@hst.aau.dk

    12. IPD Sharing Statement

    Learn more about this trial

    Investigation of the Effects of Sleep Fragmentation on Itch and Pain Sensitivity

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