Narrowband UVB Phototherapy in the Treatment of Psoriasis Vulgaris

Mechanism of Action of Narrowband UVB Phototherapy in the Treatment of Psoriasis Vulgaris

Ultra-violet light B (UVB) therapy has been used by dermatologists to treat psoriasis for decades. Only a few studies have begun to dissect the mechanism of how NB-UVB therapy causes lesion resolution. Results from this study will aid in identifying other diseases that may be treated successfully with NB-UVB. If we can identify the mechanism of action of this therapy, this may give us additional new therapeutic targets for psoriasis and other diseases. Our overall hypothesis is that UVB induces changes that will indicate a mechanism of action of this therapy in psoriasis.

Inclusion Criteria:

• Signed informed consent.
• History of chronic plaque psoriasis vulgaris, for at least six months.
• ≥10% body surface affected
• Age 18 or greater.
• Concomitant, chronic, but well-controlled medical conditions such as hypertension are allowable.
• No treatment with topical steroids for at least 2 weeks prior to entering the study
• No treatment with systemic therapies, including etretinate, UVB, PUVA, or cyclosporine, other biologics 4 weeks prior to entering the study. However, if a patient is considered to be "unstable", or would deteriorate clinically if the systemic agent is ceased (eg efalizumab), a shorter "washout" period may be considered, and would be documented in the patient charts.
• Patients who receive a stable dose of methotrexate (defined as <15mg/week for 4 months or greater) for psoriatic arthritis may be included.

Exclusion Criteria:

• Subjects who do not meet the above criteria, or who meet any of the following criteria:

  • Guttate, erythrodermic, or pustular psoriasis as sole or predominant form of psoriasis.
  • PHOTOSENSITIVITY: Hypersensitivity to sunlight or UVB light of any type; history of Lupus, PMLE, or any disease known to be worsened by UV light exposure
  • A history of non-melanoma skin cancer may be acceptable, and in this situation, the patient will be carefully evaluated.
  • Poorly controlled medical conditions of any kind.
  • Any medical condition that, in the opinion of the Investigator, would jeopardize the health or well being of the patient during the course of this study.