UV light therapy, also known as phototherapy, exposes the skin to specific wavelengths of ultraviolet light. There are two types of light therapy used to treat moderate to severe psoriasis: Ultraviolet B (UVB) and Ultraviolet A (UVA). UVB phototherapy uses light to inhibit the growth of skin cells in targeted areas and does not necessarily need to be combined with any other topical treatment. UVA, when used in conjunction with a light-sensitizing medication, slows excessive skin cell grown and can cause a significant clearing of symptoms as long as the treatment is administered on a regular basis. For mild cases of psoriasis, excimer and pulsed dye laser treatments are used when topical applications cease to be effective.
Excimer lasers emit a high intensity beam of UVB light. This form of UV light therapy treats chronic, localized psoriasis plaques. Though results vary, it takes four to ten sessions to properly gauge the skin’s response.
The pulsed dye laser uses a different frequency of light wave to treat chronic, localized psoriasis plaques. The laser destroys the blood vessels that contribute to the formation of the plaques, hindering or preventing new growth. Patients generally see improvement in six sessions. The side effect is minor bruising after the treatment. The advantage of light therapy over other more invasive methods is that it does not suppress the body’s immune response.
Psoriasis is a chronic autoimmune disease that commonly affects the skin and joints. The symptoms include red, scaly patches of skin. When the skin builds up on these areas, they turn silvery white. Severity varies from person to person, but generally falls into three categories. Mild cases affect less than three percent of the body, moderate affects three to ten percent and severe affects more than ten percent. There have been many treatments for psoriasis developed in the last ten years, from drugs that target T cells to UV light therapy, many of which are highly effective.
The type of treatment used depends on the severity of the condition, location and extent. Each technique carries with it a certain level of risk so age and attitude towards the risk are also taken into consideration. The effectiveness of each method varies from one patient to the next, so a trial and error approach is often needed to find the treatment that works best for an individual.
Topical treatments generally have the least potential for adverse reactions, so ointments will be tried before UV light therapy. If any treatment proves to be ineffective, other treatment options can be considered.