This study will test the safety and effectiveness of a novel fiber optic device for treating scalp psoriasis with ultraviolet (UV-B) light. A effective treatment is not currently available for people with scalp psoriasis. Present methods for treating psoriasis with UV-B light cannot be used for the scalp because hair is usually blocking the light from reaching the affected skin. Our method overcomes this problem with the use of a comb that has optical fibers to deliver light directly to the skin. We will evaluate this device in a clinical setting and will use the results to tailor the design of the comb before producing it in large quantities.