The Effect of Low Level Light Therapy on Histamine- and Mucuna Pruriens-induced Pruritus in Healthy Volunteers

Healthy Volunteers Clinical Trial

Official title:

The Effect of Low Level Light Therapy on Histamine- and Mucuna Pruriens-induced Pruritus in Healthy Volunteers: A Prospective, Double-blind, Randomised Sham-controlled Pilot Study

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT05369338
• Other study ID #: 33-431 ex 21/22
• Status: Completed
• Phase: N/A
• Start date: May 6, 2022
• Est. completion date: August 4, 2022

Study information

• Verified date: August 2022
• Source: Medical University of Graz
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 17
• Est. completion date: August 4, 2022
• Est. primary completion date: August 4, 2022
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 60 Years

Eligibility

Inclusion Criteria:

• Written informed consent of the participant

• Healthy test persons aged 18-60

• For female volunteers, negative pregnancy test

Exclusion Criteria:

• known allergy or hypersensitivity to histamine or the Mucuna pruriens

• history of skin diseases

• tattoos in the test area

• neoplasia in the test area

• pacemaker

• pregnancy

• epilepsy

• piercings

• fever

• local acute infection, skin inflammation/rashes

Related Conditions & MeSH terms

• Healthy Volunteers
• Pruritus

Intervention

Device:
• Low Level Light Therapy
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.
• Sham Controll
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.

Locations

Country	Name	City	State
Austria	Medical university of Graz	Graz

Sponsors (1)

Lead Sponsor	Collaborator
Medical University of Graz

Country where clinical trial is conducted

Austria, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Pruritus Intensity	Histaminergic itch is determined using a visual analogue scale (0-100) The non-histaminergic itch is determined by means of a visual analogue scale (0-100).	2 minutes
Secondary	Neurogenic inflammation	The neurogenic inflammation of histaminergic itch is determined by recording the flare area and measuring the skin temperature.; The neurogenic inflammation of non-histaminergic itch is determined by recording the flare area and measuring the skin temperature.	10 minutes
Secondary	Alloknesia	an area of alloknesia will be tested in the histaminergic itch model using cotton swabs.; an area of alloknesia is tested in the non-histaminergic itch model using cotton swabs.	10 minutes
Secondary	Hyperknesia	a hyperkneesia area is tested in the histaminergic itch model using a von Frey filament.; a hyperkneesia area is tested in the non-histaminergic itch model using a von Frey filament.	10 minutes