Overview
Many people with psoriasis experience improvement with careful, consistent exposure to sunlight. The use of sunlight for therapeutic purposes is also known as heliotherapy.
Sunlight is composed of both ultraviolet A (UVA) and ultraviolet B (UVB) light. Sunlight is believed to improve psoriasis by reducing inflammation and slowing down the growth of skin cells. Sunlight works best when it is delivered consistently to all affected areas.
Treat your psoriasis with sunlight by exposing affected portions of your skin when the sun is shining. Multiple, brief exposures are safest and most effective. You can begin by exposing your skin to sunlight for five to 10 minutes at noon each day. If your skin tolerates the exposure well, increase the amount of time for 30 seconds each day. Make sure all affected skin receives a consistent amount of exposure. Protect unaffected skin from sunburn by applying sunblock.
Your physician may suggest that you receive phototherapy in a clinical setting instead of using sunlight at home. The benefit of clinical phototherapy is that it offers consistent, regular exposure, whereas weather and seasonal changes influence how much sunlight you receive. Phototherapy equipment can also provide specific treatment with UVA or UVB light.
Most physicians agree that tanning beds do not provide safe or effective therapy for psoriasis.
Intended Outcomes
Sunlight can improve the symptoms of psoriasis and psoriatic arthritis.
Results
Sunlight has been used as a natural treatment for psoriasis for many years.
In one study, 373 Finnish people with psoriasis were sent to the sunny Canary Islands during the long, dark Finnish winter. After four weeks of sunshine, 84 percent of the participants experienced at least a 75 percent improvement in their psoriasis symptoms. Those with psoriatic arthritis also experienced significant improvements.
Constraints
With any phototherapy, your psoriasis may worsen at first before it begins healing. Redness and itching are common side effects of phototherapy. In some people, sunlight always causes worsening of psoriasis.
Excessive sunlight exposure, even the slightest sunburn, can worsen existing plaques and cause new ones to form.
Exposure to sunlight can increase your risk of developing skin cancer. Always protect unaffected skin by applying sunblock. Pregnant women should apply sunblock to the face before exposure to sunlight.
Some psoriasis medications such as Elidel and Protopic can increase your risk for sunburn.
If you are receiving clinical phototherapy, you should limit your exposure to sunlight.
Location, weather, and seasonal changes may make it difficult to maintain consistent home treatment with sunlight. For instance, it is difficult to obtain significant sun exposure in northern latitudes, especially in the winter months.