The Pros and Cons of Sun for Psoriasis Treatment
The sun: we love it. We spend hours in it, walking, biking, swimming, exploring. We fly to exotic locations to simply spend a week of our vacation time basking in its glory.
According to Time, we also spend upwards of $1.3 billion annually on sunscreen. We know by now that despite the beauty of the sun, it isn’t without risk, so we slather on sunscreen every couple of hours to decrease our risk of developing skin cancer.
However, despite the risk, the sun has been recognized as a beneficial treatment for psoriasis sufferers.
How Can the Sun Help Treat Psoriasis?
Psoriasis occurs due to rapid skin cell turnover; generally, skin cells are shed every 28 to 30 days. Once the cells are shed, new cells replace them.
With psoriasis, the cell turnover occurs every two to three days — this literally causes skin buildup, which causes the plaques characteristic of psoriasis.
Sunlight is made of UVA and UVB light. While both types of light may be beneficial in treating psoriasis, UVB light may be more effective because it is known to slow the rate of skin cell turnover and subsequent shedding.
Humidity is also helpful for treating psoriasis. Skin plaques are dry and have a difficult time retaining moisture. When the air is moist, the skin has a better chance of taking in moisture.
Phototherapy is a targeted way to get ultraviolet light. Often, phototherapy rays are UVA as opposed to UVB; because UVA rays are shorter and penetrate the skin more deeply, a medication called psoralen may be prescribed in order to increase the effectiveness of phototherapy.
When psoralen plus UVA light is used, this treatment is called PUVA. PUVA is used to treat moderate to severe plaque psoriasis, typically when other treatments have failed.
The Catch-22 of Sun-Overexposure
While sun exposure and phototherapy are proven treatment modalities for psoriasis, overexposure can actually worsen psoriasis.
Experts recommend no more than 30 minutes of per day of natural sunlight. More than 30 minutes per day not only increases the risk of skin cancer, but also can cause sunburn, which can worsen the appearance of psoriasis.
When skin cells are damaged, like when you get a sunburn, the cells can cause cell turnover — which can actually cause psoriatic plaques.
There is also something called the Koebner phenomenon associated with psoriasis. With the Koebner phenomenon, a break in the skin or damage to the skin cells exacerbates proliferation of new skin cells. This proliferation of cells then causes plaques to form. The Koebner phenomenon can happen as a direct result of a sunburn.
Protecting Yourself in the Sun
While sun exposure can treat psoriatic plaques, using sun exposure as a treatment modality should only be used at the advice of your physician.
Until advised by your doctor, you should take precautions against the sun:
- Sunblock offers protection from UVA and UVB rays. Sunscreen only protects from UVA rays. Sunblock is a better choice, as it will prevent both skin cancer and cell damage that can cause flare-ups.
- Avoid heavily-scented sun products. Products with scent can irritate the skin.
- Use a self-tanner if you really want the glow. Be aware that if you do have thick plaques, the plaques may be darker with the self-tanner.
- Avoid sun at peak sun times. This is usually between 10 a.m. and 3 p.m.