Blue Light for Treating Psoriasis Vulgaris

The purpose of this study is to determine the efficacy and safety of a blue light device for treating Psoriasis vulgaris. The study will compare a blue light treated plaque with an untreated control plaque. Additionally, two intensities of blue light are compared.

Blue light has been shown to release bioactive nitric oxide (NO) from nitrite and nitrosated proteins found in high concentrations in the skin. This bioactive NO has many physiological functions regulating immune responses, proliferation / differentiation as well as local blood Perfusion of the skin. The study will test the PSO-CT02 device, an new investigational medical device emitting blue light with a peak wavelength of 453nm on treating localised mild Psoriasis vulgaris. It can be worn on the Skin above the effected skin area. In this study Treatment (target) and control area as well as intensity of blue light are randomized. The control area will serve as reference. 50 Patients will treat the target area daily (at least 5 times/week) at home for an initial treatment period of 4 weeks. During those 4 weeks, patients will return to the study site for safety and effectiveness assessments twice. After this initiation period patients will treat their plaque for further 8 weeks (3 times/week). This is followed by a 4 week follow up phase without treatment.

Eligibility Criteria:
Inclusion Criteria:

1. Signed and dated informed consent prior to any study mandated procedure
2. Good health according to physical examination as determined by the Investigator
3. Willing and able to comply with study requirements
4. Skin type I-IV according to Fitzpatrick
5. Mild plaque-type psoriasis vulgaris with a Psoriasis area severity index (PASI) ≤10 and Body surface area (BSA)

   ≤10 and Dermatology Life quality index (DLQI) ≤ 10 at screening.
6. Presence of two comparable psoriatic plaques suitable to be defined as study areas as follows:

   1. located on extremities (plaques located on the palms or sole of the feet are not suitable)
   2. Both areas located either on lower or upper extremity
   3. Can be located on the same extremity
   4. Distance between the two study areas \> 10cm (border to border)
   5. If lesion is too large to be fully covered, partial treatment possible
7. Aged ≥ 18 years up to \<75 years
8. Reliable method of contraception for women of childbearing potential (i.e. low failure rate less than 1% per year; e.g. oral contraceptives, intra-uterine device \[IUD\] or transdermal contraceptive patch)
9. Willing to abstain from excessive sun / UV exposure (e.g. sunbathe, solarium) during the course of the study.

Exclusion Criteria:

General

1. Inmates of psychiatric wards, prisons, or other state institutions
2. Investigator or any other team member involved directly or indirectly in the conduct of the clinical study
3. Participation in another clinical trial within the last 30 days
4. Pregnant or lactating women Medical History
5. Photodermatosis and/or Photosensitivity
6. Porphyria and/or hypersensitivity to porphyrins
7. Patients with current diagnosis of erythrodermic, exfoliative or pustular psoriasis
8. Congenital or acquired immunodeficiency
9. Patients with any of the following conditions present on the study areas: Malignoma of the skin or severe actinic damage of the skin, atypical naevi or signs of hyperpigmentation, viral (e.g. herpes or varicella) lesions of the skin, fungal and bacterial skin infections, parasitic infections and atrophic Skin
10. Patients with genetic deficiencies attached with increased sensitivity to light or increased risk to dermatologic cancer (i.e. Xeroderma pigmentosum, Cockayne Syndrome, Bloom- Syndrome)