This project aims to investigate the relationship between different dimensions of catastrophizing (rumination, magnification, and helplessness) as well as some specific personality traits related to catastrophizing tendencies like anxiety sensitivity and fear sensitivity in the modulation of itch and pain intensities in an experimental setting.
Chronic itch severely affects the quality of life of patients by interfering with vital functions such as sleep, attention, and sexual activity, with an elevated expression of cognitive and emotional factors such as itch catastrophizing, worrying, as well as personality characteristics such as the predisposition to anxiety, depression, and suicidal thoughts that play an important role in the development, modification, and maintenance of itch. Moreover, chronic itch represents a significant socioeconomic burden due to a prevalence of around 10% in combination with largely suboptimal treatment since limited evidence has been found for the effectiveness of pharmaceutical interventions. The hypothesis of this project is that since it is well documented that the relationship between catastrophizing and pain and that itch and pain share many similarities, investigators can assume the existence of a similar connection between catastrophizing and itching.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
SINGLE
Enrollment
46
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.
25 spicules will be inserted in the center 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.
Aalborg University
Aalborg, Denmark
RECRUITINGReinforcement Sensitivity Theory - Personality Questionnaire (RST-PQ).
The Reinforcement Sensitivity Theory - Personality Questionnaire contains the following subscales: the Fight-Flight-Freeze System (FFFS, 10 items); the Behavioral Inhibition System (BIS, 23 items); and the Behavioral Approach System (BAS, 32 items). In total, 65 items have to be answered on a 4-point Likert-type scale ranging from 1 (not at all) to 4 (Highly).
Time frame: Baseline 1st session
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 seven component scores can be summarized in a global score ranging from zero to 21 with higher scores reflecting a worse overall quality of sleep.
Time frame: Baseline 1st session
Depression, Anxiety, Stress Scale (DASS-21)
The questionnaire measures the magnitude of depression, anxiety, and stress. Each of these three subscales consists of 7 questions answered using a 0-3 Likert scale, with 0 meaning "it did not apply to me", and 3 meaning "it applied to me very much"
Time frame: Baseline 1st session
Positive And Negative Affect Schedule (PANAS)
PANAS measures positive and negative affect dimensions. Positive affects (PA) are defined as "the extent to which a person feels active, enthusiastic, and alert". Negative affect (NA) is a condition of "general distress and unpleasable engagement".
Time frame: Baseline 1st session
Pain Catastrophizing Scale (PCS).
The PCS assesses negative and exaggerated coping concerning anticipated or experienced painful stimuli. Thirteen items have to be answered on a 5-point Likert-type scale ranging from 0 (Not at all) to 4 (all the time).
Time frame: 10 minutes after every itch induction on 1st session
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Itch Catastrophizing Scale (ICS).
The ICS assesses negative and exaggerated coping concerning anticipated or experienced itchy stimuli. Thirteen items have to be answered on a 5-point Likert-type scale ranging from 0 (Not at all) to 4 (all the time).
Time frame: 10 minutes after every itch induction on 1st session
Learned Helplessness Scale (LHS)
The questionnaire consists of 20 items, and the participant's response to each item is rated on a 4-point Likert scale ranging from strongly agree (1) to strongly disagree (4).
Time frame: 10 minutes after every itch induction on 1st session
Positive And Negative Affect Schedule (PANAS)
PANAS measures positive and negative affect dimensions. Positive affects (PA) are defined as "the extent to which a person feels active, enthusiastic, and alert". Negative affect (NA) is a condition of "general distress and unpleasable engagement".
Time frame: 10 minutes after every itch induction on 1st session
Depression, Anxiety, Stress Scale (DASS-21)
The questionnaire measures the magnitude of depression, anxiety, and stress. Each of these three subscales consists of 7 questions answered using a 0-3 Likert scale, with 0 meaning "it did not apply to me", and 3 meaning "it applied to me very much"
Time frame: Baseline 2nd session (3 days after 1st session)
Positive And Negative Affect Schedule (PANAS)
PANAS measures positive and negative affect dimensions. Positive affects (PA) are defined as "the extent to which a person feels active, enthusiastic, and alert". Negative affect (NA) is a condition of "general distress and unpleasable engagement"
Time frame: Baseline 2nd session (3 days after 1st session)
Pain Catastrophizing Scale (PCS).
The PCS assesses negative and exaggerated coping concerning anticipated or experienced painful stimuli. Thirteen items have to be answered on a 5-point Likert-type scale.
Time frame: 10 minutes after every itch induction on 2nd session (3 days after 1st session)
Itch Catastrophizing Scale (ICS).
The ICS assesses negative and exaggerated coping concerning anticipated or experienced itchy stimuli. Thirteen items have to be answered on a 5-point Likert-type scale.
Time frame: 10 minutes after every itch induction on 2nd session (3 days after 1st session)
Learned Helplessness Scale (LHS)
The questionnaire consists of 20 items, and the participant's response to each item is rated on a 4-point Likert scale ranging from strongly agree (1) to strongly disagree (4).
Time frame: 10 minutes after every itch induction on 2nd session (3 days after 1st session)
Positive And Negative Affect Schedule (PANAS)
PANAS measures positive and negative affect dimensions. Positive affects (PA) are defined as "the extent to which a person feels active, enthusiastic, and alert". Negative affect (NA) is a condition of "general distress and unpleasable engagement"
Time frame: 10 minutes after every itch induction on 2nd session (3 days after 1st session)
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'.
Time frame: 1 minute after every itch inductions
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'.
Time frame: 1 minute after every itch inductions