The purpose of the study is to test the effect of a localized narrow band ultraviolet (NB-UVB) phototherapy compared to visible light that does not produce UVB on the clearance of psoriasis plaques and resolution of itching. Localized NB-UVB (Levia®) phototherapy device is cleared by the U.S Food and Drug Administration (FDA).

This will be an ascending dose study with treatments three times per week, initial treatment dose and increasing regimen is adjusted according to the subject skin type. A suggested treatment regimen schedule provided from Lerner Medical Devices, Inc:

For subjects with skin type I: starting dose of 195 mj/cm2, for subjects with skin type II: starting dose of 330 mj/cm2, for subjects with skin type III: starting dose of 390 mj/cm2, for subjects with skin type IV: starting dose of 495 mj/cm2, for subjects with skin type V: starting dose of 525 mj/cm2, for subjects with skin type VI: starting dose of 600 mj/cm2.

The dose will be increased by 15% with each treatment, as long as there are no side effects with treatment such as burning or redness.

Inclusion Criteria:

• Adults 18 years or older with bilateral psoriasis plaques, in general good health as determined by the Principal Investigator by medical history and physical exam.
• Able to understand consent procedure
• Able to comply with protocol activities
• Must have baseline symmetric target lesions with baseline Target Lesion Score (TLS) of 6 or higher (scale of 0-12), i.e., moderate in intensity for each target.

Target Lesion Scoring: Thickness, scaling and erythema of the plaques are rated each on a scale of 0-4. The three scores are summed. The minimum score is 0; the maximum is 12. Scores of 6 or greater are considered moderate to severe.

Exclusion Criteria:

• Patients less than 18 years old
• Patients not able to understand consent procedure
• Patients unable to comply with protocol activities
• Non-English speakers: the study assessments/questionnaires/evaluations are not scientifically validated in languages other than English
• Baseline target lesions scores of less than 6
• Patients with a photosensitive disorder or on a medication which has been demonstrated in these patients to cause photosensitivity
• Patients receiving concomitant phototherapy to test sites
• Patient receiving topical medication to test sites within 2 weeks of study initiation
• Patient receiving Methotrexate, Acitretin, Cyclosporine, or other oral medications for psoriasis within 4 weeks of study initiation
• Patients receiving Etanercept (Enbrel®) within the past 2 months of study initiation
• Patients receiving Infliximab (Remicade®), Ustekinumab (Stelara®), Golimumab (Simponi®) Adalimumab (Humira®) or Alefacept (Amevive®) within the past 3 months prior to study initiation
• Receipt of an investigation agent within the past 4 weeks (or within 5 half lives) prior to study ignition
• Systemic corticosteroid therapy within the past month
• Concurrent use of prohibited medications

12 weeks