If you have psoriasis, you've probably heard that ultraviolet (UV) light from phototherapy can help make it better. Should you try tanning to get the same benefit? Not so fast, doctors warn.
Experts say tanning without a doctor's supervision isn't the best way to treat psoriasis. A trip to the beach or tanning salon may not clear up your skin, and it could be risky.
Phototherapy is safe and works well when you do it at your doctor's office. They make sure you get the right amount and type of light, and that your skin is protected during treatment. You can also do phototherapy with a special light at home, but only with your doctor's OK.
Sunlight vs. Phototherapy
The sun releases both ultraviolet A (UVA) and ultraviolet B (UVB) light.
Phototherapy typically uses UVB light. Some phototherapy treatments use UVA light, but you need to take the drug psoralen first to make your skin more sensitive to the light. If you use psoralen before you go into a tanning bed, you could get a severe sunburn.
When UVB light hits your skin, your immune system makes fewer cytokines -- inflammatory proteins that trigger psoriasis flares. That helps to slow the growth of skin cells.
Some people notice that their skin clears up during the summer months when they're out in the sun a lot. The sun may improve psoriasis a little bit. But overall, the UVB rays from sunlight don't work as well on psoriasis as the UVB rays from phototherapy.
Too much time in the sun can give you a sunburn, especially if you have light hair and skin. Skin damage from a sunburn can cause more plaques to form and make your psoriasis even worse. The link between skin injuries and psoriasis flares is called the Koebner phenomenon.
The National Psoriasis Foundation does not recommend tanning beds to treat psoriasis.
Tanning beds mainly release UVA light. They won't clear your psoriasis, because UVA light doesn't work very well on its own.
Risks of Tanning
Tanning puts your skin in contact with UVA and UVB rays. Both can be harmful.
UVA rays go more deeply into your skin than UVB rays. They damage skin and make it more likely that your skin will age more quickly, and also raise your risk for melanoma, the deadliest type of skin cancer. The more times you tan, especially in a tanning bed, the greater the odds you'll get cancer.
UVB rays cause sunburns. They also raise your risk for skin cancers.
Some of the medicines you take for psoriasis could make you more likely to get a sunburn if you tan outside or in a tanning bed, including:
- Coal tar
- Pimecrolimus (Elidel)
- Tacrolimus (Protopic)
Don't tan without first asking your doctor if it's safe for you. And definitely check with your doctor before you tan if you take medicine that makes your skin more sensitive to the sun.
The safest way to get out in the sun is to do it a little bit at a time. Get just 20 to 30 minutes a day of sunshine on your skin.
When you do go outside, wear a broad-spectrum sunscreen with UVA/UVB protection and an SPF of 30 or higher. Look for a sunscreen with zinc oxide or titanium oxide, which may be less irritating to your skin.