Tanning beds are not a good treatment for psoriasis. While UV light genuinely helps clear psoriasis plaques, commercial tanning beds emit mostly UVA light, which is the wrong wavelength. The UV type that actually treats psoriasis is UVB, and tanning beds deliver very little of it. On top of the limited benefit, tanning beds carry real risks of skin cancer, burns, and even new psoriasis flares.
Why UV Light Helps Psoriasis
Psoriasis is driven by an overactive immune response. Certain immune cells ramp up inflammation in the skin and cause skin cells to multiply far too quickly, producing the thick, scaly plaques. UV light, specifically UVB, works by dialing down that inflammatory response and boosting the body’s counter-balancing, anti-inflammatory signals. In clinical studies, patients treated with narrowband UVB showed significant drops in the key inflammatory molecules found in psoriasis plaques, but only in the plaques that actually responded to treatment. At the same time, UV exposure triggers skin cells to produce natural anti-inflammatory compounds that help calm the immune overreaction.
This is why medical phototherapy works. It targets the root immune dysfunction, not just the surface symptoms.
Tanning Beds Emit the Wrong Type of UV
Sunlight contains both UVA and UVB, but they do very different things. UVB penetrates the skin and slows the rapid growth of affected skin cells. UVA, on its own, is relatively ineffective for psoriasis. The National Psoriasis Foundation is clear on this point: although both wavelengths exist in sunlight, UVB is the one that treats psoriasis.
Commercial tanning beds are designed to tan, not to treat skin conditions. They emit mostly UVA light. The small amount of UVB they produce is inconsistent, uncontrolled, and far below what medical phototherapy units deliver. So when people report some improvement from tanning beds, it’s likely from the trace UVB exposure, and they’re getting a lot of unnecessary UVA radiation along with it.
Medical Phototherapy Is a Different Thing
Medical-grade phototherapy uses narrowband UVB, which is a very precise slice of the UV spectrum (311 to 313 nanometers). This narrow wavelength range was found to be safer and more effective than older broadband UVB, producing faster skin clearance and longer-lasting remission. It has since become the first-line phototherapy treatment for psoriasis.
These units are available in dermatology offices and as home devices prescribed by a doctor. The dosing is carefully calibrated and gradually increased to minimize burns. This level of control simply doesn’t exist with a tanning bed, where the UV output varies between machines, salons, and even sessions.
The American Society for Dermatologic Surgery is direct about this distinction: indoor tanning does not constitute phototherapy. Tanning devices found in commercial salons are not medical treatments, regardless of what tanning industry advocates may claim.
Skin Cancer and Burn Risks
The most serious concern with tanning beds is skin cancer. A large study tracking tanning bed users found that using a tanning bed just four additional times per year increased the risk of squamous cell carcinoma by 15% and melanoma by 11%. Those percentages compound with frequency and years of use. The American Academy of Dermatology opposes indoor tanning entirely and supports a ban on the sale of tanning equipment for nonmedical purposes.
For people with psoriasis specifically, burns from tanning beds create an additional problem. Sunburns and other skin injuries can trigger something called the Koebner phenomenon, where new psoriasis plaques form at the site of skin damage. Burns that penetrate through the top layers of skin are a known trigger. So a tanning session that goes slightly too long could leave you with more psoriasis, not less. This risk is especially hard to manage in a tanning bed because the UV intensity isn’t calibrated to your skin type or current level of sensitivity.
Medication Interactions Add More Risk
Many common psoriasis treatments increase your skin’s sensitivity to UV light. Methotrexate, one of the most widely prescribed systemic medications for psoriasis, can cause photosensitivity that raises your risk of a severe burn reaction. Some topical treatments also make skin more reactive to sunlight and UV exposure. If you’re using any of these medications and step into a tanning bed, you’re significantly more likely to burn, which circles back to the Koebner risk of triggering new plaques.
Medical phototherapy accounts for these interactions. Your dermatologist adjusts UV doses based on what medications you’re taking. A tanning salon doesn’t have that information and wouldn’t adjust the equipment even if it did.
Better Options for UV-Based Treatment
If you’ve noticed that sun exposure or even tanning beds seem to help your psoriasis, that’s a signal that your skin responds to UV, and it’s worth pursuing that through the right channels. Narrowband UVB phototherapy, whether in a clinic or with a home unit, delivers the effective wavelength in controlled doses without flooding your skin with UVA radiation. Home phototherapy units are increasingly covered by insurance and allow you to treat on your own schedule, typically three times per week.
Brief, controlled sun exposure is another option some dermatologists recommend, starting with just a few minutes and building gradually. This provides a natural mix of UVA and UVB without the concentrated UVA exposure of a tanning bed. The key difference from tanning beds is the ability to control duration and avoid burns.
The bottom line is straightforward: UV light treats psoriasis, but tanning beds are the wrong tool for delivering it. They provide the wrong wavelength, at uncontrolled doses, with well-documented cancer risk. Medical phototherapy uses the right wavelength with the precision that psoriasis treatment requires.