Clinical Research Directory

Mechanisms Underlying the Nocibo Effect of Contagious Itch. in Both Histaminergic and Nonhistaminergic Itch

The study consists of one experimental session of approximately 1½ hours. The participant will fill in a series of questionnaires about how you perceive itch and pain, and about some traits of your personality, such as depression, anxiety and stress. Afterwards, three areas will be selected on each forearm of the subjects. Two areas will be treated with histamine, two with cowhage, and two with vehicle. One application of each substance will be conducted including the contagious itch component. During the 10 minutes of the application of the pruritogens, itch and pain will be continuously monitored using a VAS scale.

Mechanisms Underlying the Placebo Effect in Both Histaminergic and Non-histaminergic Itch

The study consists of one experimental session of approximately 1½ hours. The participant will fill in a series of questionnaires about how you perceive itch and pain, and about some traits of your personality, such as depression, anxiety and stress. Afterwards, two areas will be selected on each forearm of the subjects. The four areas will be treated with the same vehicle cream for 20 minutes, in order to test the placebo effect. At the end of the cream application, two areas will be randomly treated with histamine while cowhage will be applied on the other two areas. During the 10 minutes of the application of the pruritogens, itch and pain will be continuously monitored using a Visual Analog Scale.

Reducing Itch With Hypnosis and Virtual Reality

Chronic itch is a disabling condition with currently limited treatment options. Virtual reality (VR) is a relatively new approach that provides immersion in another environment and has been shown to have a temporary itch mitigating potential. Hypnosis, which is a state of relaxation, has been successfully applied with more long-term treatment effects in the specific case of itch as a result of severe atopic dermatitis. However, hypnosis tends to depend on an individual's susceptibility, or ease, to come into a hypnotic state. A combination of VR and hypnosis (VRH) has been put forward since it may combine the longer lasting effects of hypnosis with VR making the hypnosis more accessible by facilitating imagination. Even though VRH is a promising avenue, it has never been investigated in the context of itch. In this randomized controlled trial, comparing a VRH treatment with a waiting list control group after 6 sessions and at follow-up, it is aimed to assess the effectiveness of VRH in reducing itch along with its psychological burden in adult individuals with therapy-resistant disabling itch.