The Effect of Low Level Light Therapy on Histamine- and Mucuna Pruriens-induced Pruritus in Healthy Volunteers
Condition: Healthy Volunteers
MeSH terms: Pruritus
Study type: Interventional

Summary: 
      This is a prospective, double-blind, randomised, sham-controlled study whose primary aim is
      to test whether LLLT changes the intensity of itch after histamine application in healthy
      volunteers compared to sham application.
    

Detailed description: 
      Rationale and relevance of the study

      Low-level light therapy (LLLT) is a method of photobiomodulation that involves the clinical
      application of light with wavelengths typically in the range of 600 to 1100 nm and with a
      typical power density of 5 mWcm² to 5 Wcm².

      Clinical studies have demonstrated positive effects of LLLT on pain processing, which is
      attributed to a reduction in neurogenic inflammation and associated neuronal sensitisation.
      This has been proven by testing for hyperaesthesia or allodynia. In the course of neurogenic
      inflammation, histamine liberation also occurs, which can be associated with itching. Chronic
      itching is also frequently associated with somatosensory abnormalities in analogy to chronic
      pain. Itch-associated dysaesthesias, such as mechanical allocnesia and hyperknesia, can be
      seen as evidence of neuronal sensitisation in pruritus patients.

      Oliviera et al. were able to demonstrate an antipruritic effect of LLLT in a case observation
      of five burn victims. By irradiating with laser, whose photobiomodulative mechanisms are
      similar to the mechanisms of LLL therapy, this effect was also investigated in lichen planus
      patients. The effect of LLL on pruritus can be demonstrated in the case observation of five
      burn victims.

      Itch models can be divided into histamine-induced and non-histamine-induced. To date, there
      has been no structured investigation of the antipruritic effect of LLL, nor is it clear to
      what extent the itch-inducing mechanism has an influence on the suspected efficacy of LLL.
    

Intervention name(s): Low Level Light Therapy; Sham Controll
Intervention type(s): Device; Device
Intervention description(s): The application of LLL is applied for 12 minutes using Repuls 7 (Repuls Lichtmedizintechnik GmbH, Vienna). This is a class IIb medical device. It applies pulsed red light of a frequency of 640nm. The intensity is 175 mWcm-2, which corresponds to a power density of 4,100 mW. The pulse frequency is set to 2.5 hz.
The device is positioned 7cm from the skin using a distance ring. The sham treatment is performed with the same device and the same distance ring without activating it.; The application of LLL is applied for 12 minutes using Repuls 7 (Repuls Lichtmedizintechnik GmbH, Vienna). This is a class IIb medical device. It applies pulsed red light of a frequency of 640nm. The intensity is 175 mWcm-2, which corresponds to a power density of 4,100 mW. The pulse frequency is set to 2.5 hz.
The device is positioned 7cm from the skin using a distance ring. The sham treatment is performed with the same device and the same distance ring without activating it.
Other intervention name(s): LLLT
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Prospective, double-blind, randomised, sham-controlled
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Basic Science