Characterization of New Human Models of Non-histaminergic Itch and Their Interaction With the TRPM8 Receptor
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 发起方
- 入组人数
- 20
- 试验地点
- 1
- 主要终点
- Superficial blood perfusion
研究概览
简要总结
In this experiment the investigators would like to assess if papain induces an itch sensation comparable to the itch sensation induced by cowhage and to confirm that the mechanism of action of papain follows the non-histaminergic pathway.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Single (Participant)
入排标准
- 年龄范围
- 18 Years 至 60 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Healthy men and women
- •18-60 years
- •Speak and understand English
排除标准
- •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)
研究组 & 干预措施
Doxepin Application
During the session each forearm of the subject will be divided into four squared areas (2.5x2.5 cm), see Figure 4. Four of the areas will be treated with doxepin for 1 hour and 30 minutes (with a patch to deposit 1.2 grams of cream). Each patch will be covered with Tegaderm I.V., an occlusive, adhesive dressing (3M), for at least 1½ hours 48. At the end of the pre-treatment period, the patches will be removed and the skin will be cleaned with alcohol.
干预措施: Doxepin Topical (Drug)
Itch Induction
After Doxepin removal, Then tests with papain, cowhage, histamine or vehicle will be conducted. Each substance will be randomly applied in two areas, one pretreated with doxepin and one with no pre-treatment.
干预措施: Papain (Drug)
Itch Induction
After Doxepin removal, Then tests with papain, cowhage, histamine or vehicle will be conducted. Each substance will be randomly applied in two areas, one pretreated with doxepin and one with no pre-treatment.
干预措施: Histamine (Drug)
Itch Induction
After Doxepin removal, Then tests with papain, cowhage, histamine or vehicle will be conducted. Each substance will be randomly applied in two areas, one pretreated with doxepin and one with no pre-treatment.
干预措施: Cowhage (Other)
结局指标
主要结局
Superficial blood perfusion
时间窗: 15 minutes
Superficial blood perfusion is measured by a Speckle contrast imager (FLPI, Moor Instruments, England).
Measuring itch intensity by computerized Visual Analog Scale Scoring
时间窗: 15 minutes
The subjects will 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" and similarly for sensations of stinging/pricking and burning, both of which are frequently associated with the sensation of itch.
Measuring pain intensity by computerized Visual Analog Scale Scoring
时间窗: 15 minutes
The subjects will 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".
Measuring Alloknesis
时间窗: 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). This stimulator is applied 0.5 cm outside the area of itch provocation.
次要结局
- Measurement of Cold Detection Thresholds (CDT)(15 minutes)
- Measurement of Cold PainThresholds (CPT)(15 minutes)
- Measurement of Heat Pain Thresholds (HPT)(15 minutes)
- Measurement of Warm Detection Thresholds (WDT)(15 minutes)
- Measurement of Pain to Supra-threshold Heat Stimuli(15 minutes)
- Measurement of Mechanical Pain Thresholds (MPT)(15 minutes)
- Measurement of Mechanical Pain Sensitivity (MPS)(15 minutes)
- Touch Pleasantness (TP)(15 minutes)
研究者
Silvia Lo Vecchio
PhD, Assistant Professor
Aalborg University