Laser Induced Changes to Innervation and Vascularisation of Psoriatic Skin

Study Overview
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Brief Summary
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The researchers investigate the effect of a treatment with selective photothermolysis using a 595 nm pulsed dye laser on the blood vessel density and the nerve fibre density of a psoriatic lesion. By comparing tissue samples collected before and after two treatments, the researchers determine the relative effect of laser therapy on the (hyper)innervation of psoriatic skin.

Detailed Description
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Vascular laser therapy for psoriasis seems to achieve a remarkably long treatment-free duration of remission. But why would sub-second heating of the blood vessels of the skin result in a year-long resolution of an infamously stubborn condition? Unraveling the mechanism of action of laser therapy would not only allow for the improvement of existing laser therapy protocols but also, could open the door to a whole new range of interventions offering quasi-permanent solutions for patients. There is a high need for such enduring therapies: Psoriasis is both, a common and a costly skin condition. It affects between 1% and 9% of the population and has a very severe impact on the quality of life of the patient. It's chronic character implies lifelong treatment, and the associated risks and effort This project aims to assess the effect of laser therapy on the blood vessels and (peripheral) innervation of psoriasis plaques. The primary objective is to quantify the regression and recovery of nerves compared to blood vessels. The researchers hypothesize that the recovery of nerves after Selective Photo Thermolysis (SPT) is decreased compared to the recovery of blood vessels.

Official Title
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A Preliminary Study on the Effect of Photothermal Laser Therapy on the Vascularization and Innervation of Psoriatic Lesions

Conditions
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Psoriasis Vulgaris

Intervention / Treatment
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* Device: 595 nm Pulsed dye laser (Candela V-beam perfecta)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 - 69 years of age Psoriasis vulgaris Skin type I - III Minimal surface of lesion of 3 cm2 Contralateral psoriasis vulgaris lesions located on chest, back, or upper legs Exclusion criteria A potential subject who meets any of the following criteria will be excluded from participation in this study if: The participant uses other treatments (than laser therapy) during the study or two weeks before the start of the study that are known to affect psoriasis The participant suffers from any known neurological, vascular, or immunological condition other than psoriasis. The participant is allergic to lidocaine

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 69 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Sequential Assignment
Interventional Model Description: single blinded intra-patient comparison
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Laser therapy<br>595 nm Pulsed dye laser (PDL) therapy for psoriasis | Device: 595 nm Pulsed dye laser (Candela V-beam perfecta)<br>* 595 nm pulsed dye laser therapy. 2 treatments Fluence   6 - 9 J/cm^2 Pulse duration   0.45 - 3.0 ms 33% overlap.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Recovery ration | Relative change in the ratio of the linear nerve density and linear blood vessel density. | 6 months. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Recovery ratio vs lymphocyte infiltration | Correlation between change in the ratio of the linear nerve density and linear blood vessel density versus change in number of infiltrating lymphocytes | 6 months | 
| Clinical improvement | Change in severity determined using a visual-analogue scale. | 6 months |