6 Top Questions About Psoriasis and the Sun

Some swear by it. Others avoid it at all costs. Here, experts answer your Qs about using the sun to help treat psoriasis.

by Stephanie Stephens Health Writer

For Jaime Lyn Moy and her son, Andrew, having psoriasis is "like mother, like son." Moy, 43, was diagnosed in 2006 at age 29, and her son, now 21, was diagnosed in 2002 at age 4. They both also have psoriatic arthritis. This mother-and-son duo have tried different things to keep their plaques at bay, including spending time in the sun.

And they're far from the first. A review published in Dermatology and Therapeutics says sunlight has been used to heal skin since as early as 1500 B.C., and that researchers have long known that ultraviolet (UV) light can delay rapid skin-cell growth in people with psoriasis.

But what about the potential risk of damage from UV rays that dermatologists often warn about? To sun or not to sun? Those are questions you should be asking and our experts are going to help us answer.

Can the Sun Really Help Psoriasis Symptoms?

Dermatologists agree that because the sun's rays slow the unwanted skin-cell growth that happens with psoriasis, they can potentially also reduce inflammation and skin scaling.

Moy, who volunteers for the National Psoriasis Foundation, remembers when Andrew was first diagnosed years ago, in the summertime. His doctor told her to "put swim trunks on him and let him run around outside with no sunscreen."

"He was taking medication and using topical creams, but his dermatologist said to 'do the sun as well,'" she says.

While some dermatologists, like Andrews, do recommend sun therapy, exactly how UV light helps psoriasis isn’t 100% known. "We don't understand the effects completely, but we know it has something to do with chemical signaling pathways," says dermatologist Kyle Cheng, M.D., at the Ronald Reagan UCLA Medical Center in Santa Monica, California. "In a nutshell, UV light helps rebalance the immune system for your skin, which in turn may help prevent or decrease the amount of psoriasis."

Do I Have to Wear Sunblock?

Yes. Yes, and yes. If you do decide to bask in the day's rays, follow the same guidelines as other people who don't have psoriasis, says the National Psoriasis Foundation (NPF). Use a broad-spectrum, water-resistant product, with an SPF of 30+. There’s one caveat, however: Since sunscreen may absorb into skin and irritate psoriasis patches, choose a sunblock instead made with ingredients like zinc oxide or titanium dioxide which are more gentle for sensitive skin.

Slather on the sunblock to all exposed skin areas at least 15 minutes before bounding outside. Don't skimp on face, scalp, upper back and shoulders, which tend to burn easily. And don’t forget to reapply every two hours—especially if you’ve been sweating, swimming or showering.

Does Darker Skin Provide Any Protection from the Sun?

The American Academy of Dermatology (AAD) says that yes, thanks to melanin (the pigment in skin that protects against sun damage), people of color do have a lower risk of developing skin cancer than Caucasians. But when they do get it, it's usually diagnosed at a more advanced stage and that makes treatment more difficult. Roughly 52% of African Americans and 26% of Hispanics find out they have melanoma after it has already started to spread, compared to 16% of Caucasians.

Although Moy and her son like being in the sun (they live in Detroit where the sun shines 180 days of the year), Moy has fair skin and, not surprisingly, says she burns "pretty easily." "It was never really an option for me to be in the sun for any extended period of time to try and help my psoriasis," she says. Her husband (Andy's father) is of Chinese descent, so Andy's skin is more olive, making it slightly less risky for him to catch some rays.

Ironically, even if you never sunburn, you can get skin cancer. The AAD says that approximately 9,500 of us are diagnosed with skin cancer every single day and reminds us that exposure to natural and artificial ultraviolet light increases risk for all types of skin cancer.

Add to that, research has found that people with psoriasis appear to have an increased risk of developing cancer, specifically skin cancer, possibly due to the fact that psoriasis is an inflammatory disease and inflammation is strongly linked to cancer.

Does Sun Therapy Work for Everyone with PsO?

"Sunlight definitely isn't for everybody," says dermatologist Jennifer Stein, M.D., of NYU Langone Health. "Although some patients report that they improve in the summer, some patients do worse."

When she has gotten too much sun and a resulting sunburn, Moy says she sometimes does get a "little flare of psoriasis," even though she's "really well managed" most of the time.

"I don't really recommend hanging outside in the sun to treat psoriasis, especially if it's extensive, which requires more targeted therapies," says Dr. Cheng. "Patients sometimes tell me, 'My other doctor said to just go outside,' but knowing what we do about skin cancer, you really can't do that anymore."

For more advanced psoriasis cases, Dr. Cheng's first line of defense isn’t the sun. Rather it includes biologics such as Cosentyx (secukinumab) and Tremfya (guselkumab).

For people who swear by the sun for treating their psoriasis (or pregnant women who shouldn’t take certain medications), Dr. Stein and other dermatologists prefer phototherapy. "It’s a reliable and safer way of treating skin with UV light in a controlled way," says Dr. Stein.

But What Is Phototherapy?

In a nutshell, phototherapy is “pretend sunlight.” Indoor phototherapy treatments use controlled UV light therapy to reduce inflammation and slow down the creation of skin cells.

Sunlight contains both ultraviolet light A or UVA, and ultraviolet light B or UVB, which is the ray that the National Psoriasis Foundation (NPF) says is more effective for treating psoriasis.

With phototherapy in a doctor's office, a patient receives 15 to 30 minutes of narrow spectrum UV light, known as narrow-band UVB. People typically need 20 to 36 sessions for best results. That type of a "tiny, targeted, narrow band of light" at a specific frequency prevents a person from getting everything from the sun.

"Light therapy is effective but it's also not going to be a cure-all for most people," says Dr. Cheng. He expects up to 60% of patients will have a 75% clearance if they utilize ongoing phototherapy conducted two-to-three times a week. The Institute for Quality and Efficiency in Health Care says it's estimated that symptoms improve noticeably or go away completely for a while in more than half the people who get treated.

Are Tanning Beds a Form a Phototherapy?

Not at all. The NPF along with the Centers for Disease Control and Prevention discourage the use of tanning beds. Period.

Tanning beds are shown to increase skin cancer risk due to their use of UVA light. Always remember that the dark tan you love today that looks so good and temporarily eases psoriasis symptoms—no matter how you got it—could be the one that causes skin cancer for you later in life.

There's lots of research and proven advice available to keep you safe and healthier if you have psoriasis. "Use the treatments your doctor recommends to help manage your disease," Moy says, and she ought to know. "Plenty of times it's so easy to feel defeated, but it's so important when you have a chronic disease to have hope. Things really will get better but may take time."

Stephanie Stephens
Meet Our Writer
Stephanie Stephens

Stephanie Stephens is a very experienced digital journalist, audio/video producer and host who covers health, healthcare and health policy, along with celebrities and their health, for a variety of publications, websites, networks, content agencies and other distinctive clients. Stephanie was accepted to THREAD AT YALE for summer 2018 to author and produce an investigative series. She is also active in the animal welfare community.