Natural sunlight can significantly improve, or even clear, psoriasis. Ultraviolet (UV) light from the sun suppresses the skin’s immune response and damages the production of skin cells, slowing their overproduction and reducing scaling. Daily, short, nonburning exposure to sunlight clears or improves psoriasis in many people. Therefore, sunlight may be included among initial treatments for the disease (Source: National Institutes of Health, Department of Health and Human Services, Questions and Answers about Psoriasis, January 2002, online at www. niams. nih. gov/hi/topics/psoriasis/psoriafs. htm).
Regular daily doses of sunlight, taken in short exposures with adequate sun protection, are strongly recommended. Sun protection is vital not only to prevent sunburn, which may make psoriasis worse, but also to reduce skin damage from the sun’s UV radiation. This outdoor approach to treating psoriasis is often referred to as climatotherapy or phototherapy. Some people travel to Florida, Hawaii, the Caribbean, or the Dead Sea in Israel (where special clinics offer treatment solariums and supervised medical assistance) to use swimming in sulfur or mineral baths along with natural sunlight. In some countries, medical plans actually cover trips to these types of sunny climates and mineral spas for subscribers with psoriasis.
When you can’t get to sunshine, medically supervised administration of light via UVB lamps may be used to minimize widespread or localized areas of stubborn and unmanageable psoriasis lesions. UVB light is also used when topical treatments have failed, or in combination with topical treatments. The short-term risks of using controlled UVB exposure to treat psoriasis are minimal, and long-term studies of large numbers of patients treated with UVB have not demonstrated an increased risk of skin cancer, suggesting that this treatment may be safer than sunlight. (Sunlight has both UVA and UVB radiation; UVA causes skin cancer, while UVB mainly triggers sunburn.) UVB treatments are considered one of the most effective therapies for moderate to severe psoriasis, with the least amount of risk. There are even sources of UVB light therapy, called narrow-band UVB, that give off only the part of the UV spectrum band that is most helpful for psoriasis and that reduce the risk of wide-band UVB light.