Mayo Clinic Health Letter: UV light slows skin cell overgrowth, alters immune system

Apr 9 2010

Ultraviolet (UV) light -- a culprit behind sunburns, wrinkles and skin cancer -- offers benefits for some skin conditions, according to the April issue of Mayo Clinic Health Letter.

Various ultraviolet treatments of the skin are potential therapy options for conditions that include:

• Psoriasis
• Vitiligo, a loss of skin pigment that often appears as white blotches on the skin
• Eczema, also called dermatitis
• Persistent itching (pruritus)
• Cutaneous T-cell lymphoma, a rare form of cancer that usually involves the skin
• Graft-vs-host disease -- a complication associated with blood and bone marrow transplants

It's not fully known how ultraviolet light benefits these skin conditions. Perhaps, UV light slows skin cell overgrowth and alters the immune system.

Health care providers administer UV light therapy with a variety of tools. Options range from full-body units such as light beds to handheld lights. Other tools include small light cabinets for the hands or feet; combs that emit light from the tines for reaching the scalp; and lasers, which can focus a high-intensity beam of UV light on a small area.

UV therapy sessions may last from a few seconds to an hour. Consistency is one of the keys to success. Patients may need therapy two to seven days a week. Dozens of sessions may be needed to achieve adequate response. Once the condition has improved, patients may be able to switch to a less-frequent maintenance schedule.

Benefits aside, long-term UV therapy still presents an increased risk of skin cancer. As with any therapy, the potential benefits need to be weighed against the potential risks. Fortunately, skin cancers generally can be removed and successfully treated when they are detected early.

Source: https://healthletter.mayoclinic.com/