Sunlight and Psoriasis: What a Dermatologist Wants You to Know

Is sun exposure *actually* healthy for people with psoriasis?

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Pretty much everyone (especially if you’re from somewhere that gets inches and inches of snow in winter) in looks forward for those magical weeks in June or July when it *finally* feels like summer’s here. But if you have psoriasis, an inflammatory skin condition in which your skin cells turn over too rapidly, often creating thick, scaly plaques, you might come to appreciate summer more than most.

That’s because the ultraviolet light from the sun’s rays appears to be naturally soothing for psoriasis symptoms. So dermatologists actually encourage patients with psoriasis to seek out sun exposure, even though that sounds counterintuitive to every single bit of skin advice you’ve ever read in a women’s magazine or website.

“Psoriasis patients are the dermatologist's one exception to the rule of staying out of the sun,” says Suzanne Friedler, MD, a dermatologist in New York City.

The Benefits of Sunlight for Psoriasis

It’s well-known that UV light, and UVB rays in particular, can help treat psoriasis. UVB rays penetrates the skin and slow the growth of affected skin cells, according to the National Psoriasis Foundation. Sunlight may reduce inflammation, cause skin cells to turn over less rapidly, and improve the appearance of psoriasis plaques.

Sunlight also helps promote the production of vitamin D, which also can help treat psoriasis by causing skin cells to slow down in how quickly they turn over, according to Dr. Friedler. In fact, a commonly prescribed class of topical therapies for psoriasis is called calcipotriene, which contains a vitamin D derivative.

What’s the Difference Between Sunlight and Phototherapy?

You can expose yourself to UVB rays by spending a few minutes in the sun a few times a week; this is sometimes called solar therapy.

Phototherapy for psoriasis, on the other hand, involves in-office (or sometimes at-home) treatment that exposes you to specific wavelengths of UVB light from a machine. Your dermatologist may recommend phototherapy, which usually involves office visits a couple times a week, if your psoriasis hasn’t improved after you’ve made lifestyle changes for psoriasis and tried various topical therapies.

Phototherapy is not at all the same thing as using a tanning bed, which is considered a cancer risk and not recommended for psoriasis (or anyone). The UV light delivered via phototherapy has  been filtered to get rid of wavelengths that damage skin.

Laser treatment, such as an excimer laser, is basically a much more intense form of phototherapy. It’s good for psoriasis lesions that are contained to a smaller area of the body rather than all over. The laser is a very concentrated beam of UV light that’s also been filtered to remove skin-damaging wavelengths.

What Are the Risks of Sun Exposure for Psoriasis?

Even though some sunlight is healthy for psoriasis-prone skin, too much is not good for you.

  • UV exposure can raise your risk of skin cancer, so it may not be recommended if you have a strong personal or family history of skin cancer or melanoma.

  • Certain medications for psoriasis can make you more photosensitive. This means you might be more likely to burn. These medications can include vitamin A derivative creams like tazarotene and coal tar. Before you self-medicate with sun exposure, you should always ask your doctor if you may be taking any medication that can make your skin more sensitive to the sun.

  • Sunburn can make your psoriasis symptoms worse. In a classic example of the dose makes the poison, too much sun exposure can actually backfire and worsen psoriasis symptoms. This is due to something called the Koebner phenomenon, in which any injury to the skin (be it sunburn or a cut or scratch) can trigger more psoriasis to develop, says Dr. Friedler.

How Can You Get Safe Sun Exposure with Psoriasis?

“Allow the sun to hit your psoriatic plaques, but do take care to protect other parts of your body,” cautions Dr. Friedler. Here’s how:

  • Aim for multiple short exposures of sunlight, not one eight-hour day at the beach.

  • Start with five to 10 minutes of noon-time sun exposure daily, advises the Psoriasis Foundation; you can gradually build up from there once you see your skin is tolerating it.

  • Work with your doctor; he or she may want to check you more frequently to make sure your skin isn’t experiencing sun damage and that your psoriasis symptoms are improving.