Clinical trial NCT06328530: Itch Sensation Induced by Simultaneous Application of Pruritogens (Spatial Summation)
Official title: Repetitive Applications of Pruritogens and Effects of a Cutaneous-induced Pain Stimulation on Nonhistaminergic Itch Perception
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Histamine
Cowhage
Lead sponsor: Aalborg University
Sponsor class: OTHER
First posted: 2024-03-25
Enrollment: 24
Sex: ALL
Minimum age (years): 18
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: SINGLE_GROUP
Intervention model description: The participants will randomly receive applications of cowhage and histamine.
Primary purpose: BASIC_SCIENCE

Brief summary: In This experiment, the investigators would like to design a new itch model based on the spatial summation of pruritic stimuli. The hypothesis behind this study (spatial summation) is that two simultaneous applications of pruritogens will result in higher itch sensation compared with a single application of pruritogen.

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. In order to mimic a clinical itch condition as presented in patients, the aim of the project is to investigate a new itch model based on the spatial summation of pruritic stimuli. The aim of this experiment is to assess the itch sensation induced by simultaneous application of pruritogens (spatial summation). In particular, the purpose is to evaluate if a single application of cowhage/histamine (non-histaminergic and histaminergic itch respectively) results in a lower itch sensation compared to two simultaneous applications of the pruritogens, on the same arm or in different arms.

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 addictive drugs
* Previous or current history of neurological (e.g. neuropathy), immunological (e.g. asthma, immune deficiencies, arthritis) musculoskeletal (e.g. muscular pain in the upper extremities,), cardiac disorder, or mental illnesses that may affect the results
* 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 (e.g. atopic dermatitis, pruritus nodularis, eczema, psoriasis)
* Moles, scars, or tattoos in the area to be treated or tested.
* Consumption of alcohol or painkillers 24 hours before the study days and between these
* Acute or chronic pain
* Participation in other trials within one week of study entry (four weeks in the case of pharmaceutical trials)

Primary outcomes:
measure: Assessment of itch
timeFrame: 1 minute after every itch inductions
measure: Assessment of pain
timeFrame: 1 minute after every itch inductions
Secondary outcomes:
measure: Alloknesis
timeFrame: 12 minutes after every itch inductions
measure: Mechanically evoked itch
timeFrame: 15 minutes after every itch inductions
Other outcomes:
Locations:
city: Aalborg
country: Denmark
facility: Aalborg University
Study officials:
References: