Psoriasis is a chronic autoimmune condition characterized by an overactive immune system that accelerates the growth cycle of skin cells. Normally, skin cells grow and shed over approximately 28 days, but in people with psoriasis, this process speeds up to just three to seven days, causing a buildup of thick, scaly plaques. Many individuals have noticed that natural sun exposure offers relief, leading to the assumption that commercial tanning beds could serve as a convenient, year-round remedy. Examining whether a tanning bed can replicate the therapeutic effects of sunlight requires comparing the light used in medical treatment versus what is emitted commercially.
How Ultraviolet Light Affects Psoriasis
The therapeutic effect of light on psoriatic plaques depends on the specific wavelength of ultraviolet (UV) radiation that penetrates the skin. The beneficial component is primarily Ultraviolet B (UVB) light, which has a shorter wavelength and affects the top layers of the skin (the epidermis). When absorbed, UVB light modulates the body’s immune response in the skin, a process central to the development of psoriasis.
This radiation helps induce programmed cell death (apoptosis) in the overactive T-cells and keratinocytes driving rapid skin cell production. By suppressing this localized immune activity, the light slows the accelerated growth rate, allowing the skin cycle to return toward a more normal rate. The controlled application of UVB light reduces the redness, thickness, and scaling associated with the plaques. The most effective portion of the spectrum is a narrow band of UVB light, identified as being around 311 to 312 nanometers.
Tanning Bed Light Versus Medical Treatment
The fundamental difference between a commercial tanning bed and clinical phototherapy is the light spectrum they emit and the precision of control.
Clinical Phototherapy
Clinical phototherapy utilizes specialized medical devices that deliver Narrowband UVB (NBUVB) light, specifically targeting the therapeutic 311–312 nm wavelength. This high-precision approach maximizes anti-inflammatory and cell-slowing effects while minimizing exposure to damaging wavelengths. Treatments are administered under a dermatologist’s supervision, who precisely calculates the exposure time and dosage based on the individual’s skin type and condition.
Commercial Tanning Beds
Commercial tanning beds are designed to induce a tan, which is a sign of skin damage. To achieve this, they primarily emit high-intensity Ultraviolet A (UVA) light, often comprising 90% or more of the total output. UVA penetrates deeper than UVB, but it is largely ineffective for treating psoriasis unless combined with a photosensitizing oral medication (PUVA therapy). The small, unregulated amount of UVB light they emit is inconsistent and not at the optimal therapeutic wavelength.
Medical consensus advises against using commercial tanning beds as a substitute for prescription phototherapy due to the poor quality of light and lack of regulated dosing. Using a tanning bed subjects the skin to a high dose of damaging UVA radiation with an uncontrolled, insufficient dose of beneficial UVB. This practice does not offer reliable therapeutic benefit and significantly increases health risks. The goal of a tanning bed is cosmetic, making them fundamentally unsuitable for disease management.
The Serious Health Risks of Commercial Tanning
The primary and most serious risk associated with commercial tanning bed use is the elevated chance of developing skin cancer, including melanoma, basal cell carcinoma, and squamous cell carcinoma. The high concentration of UVA light penetrates deeply into the skin, causing DNA damage that contributes to carcinogenesis. For individuals who use a tanning bed just once before the age of 35, the risk of developing melanoma increases by approximately 75%.
The World Health Organization’s International Agency for Research on Cancer classifies indoor tanning devices in its highest cancer risk category, labeling them as “Carcinogenic to Humans.” Beyond the risk of cancer, exposure to this uncontrolled UV radiation accelerates photoaging, leading to the premature appearance of wrinkles, sunspots, and leathery skin texture. Additionally, the intense UV exposure can damage the immune system, potentially making the body less able to fight off infections. These contraindications make the use of commercial tanning beds a dangerous practice, particularly for individuals with a pre-existing skin condition.