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Completed

NCT Number: NCT05369338

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

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.

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Key information

Conditions

Healthy Volunteers

Age range

18 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Medical university of Graz

Graz, 8010, Austria

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Low Level Light Therapy

Device

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 names: LLLT

Sham Controll

Device

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.

Primary outcomes

  1. Pruritus Intensity

    Time frame: 2 minutes

    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).

Secondary outcomes

  1. Neurogenic inflammation

    Time frame: 10 minutes

    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.

  2. Alloknesia

    Time frame: 10 minutes

    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.

  3. Hyperknesia

    Time frame: 10 minutes

    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.

Sponsors and collaborators

Lead sponsor

Medical University of Graz

Other

Registry information

Official study 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

Important dates

Study start
2022
Primary completion
2022
Study completion
2022
First posted
May 11, 2022
Registry last updated
Aug 15, 2022

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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