Psoriasis is a chronic skin condition resulting from an autoimmune disease in which the immune system produces too many skin cells. The cells accumulate on the surface of your skin. The shed skin cells form red welts that are thick and raised and may have silvery scales. The welts can be painful or itchy.
Common treatments include topical medications that reduce inflammation, or oral medications that suppress your immune system. However, another form of treatment for psoriasis involves one of the most natural elements on earth: the sun.
Phototherapy is a treatment for psoriasis that uses natural or synthetic lights. You absorb the ultraviolet rays through your skin as you sunbathe outside, or by using a special light box.
The sun’s ultraviolet rays are made up of UVA and UVB rays. UVB rays are more effective at treating psoriasis symptoms, because they slow the rapid rate of skin growth and shedding.
Your doctor may choose to treat your psoriasis with UVA rays instead of UVB. UVA rays are shorter than UVB and penetrate your skin more deeply. Because UVA rays are not as effective in clearing the signs of psoriasis, a medication called psoralen is added to the light therapy to increase effectiveness. This combination treatment is generally abbreviated as PUVA.
Psoralen, a drug that causes photosensitivity, makes your skin more sensitive to the sun’s rays. You’ll take an oral form of the drug or use a topical prescription on the affected skin before your UVA treatment to help your skin absorb the light. Short-term side effects include nausea, itching, and redness of the skin.
PUVA is used to treat moderate to severe plaque psoriasis. It may be used when topical treatments and UVB therapy have not been successful. Thicker psoriasis plaques respond well to PUVA because it is absorbed deeper in the skin. Hand and foot psoriasis are often treated with PUVA therapy.
Although sunlight can benefit psoriasis, you should take care to protect yourself from sunburn. This condition predominantly strikes light-skinned people, who are at a greater risk for sunburn and dangerous forms of cancer such as melanoma. Natural sunbathing is not monitored in a medical setting like phototherapy is, and medications you may be taking can increase photosensitivity. This can heighten your risk of sunburn and skin cancer.
You should still wear sunscreen, even when you want your skin to soak up the sun’s rays. For the best (and safest) results, follow these tips:
- Apply broad-spectrum sunscreen to all areas of unaffected skin.
- Wear sunglasses.
- Do natural sun therapy sessions when the sun is strongest.
- Stay outside for only 10 minutes at a time to reduce the risk of sun damage. As long as your skin can tolerate the exposure, you can slowly increase your sunbathing by 30 seconds to one minute each day.
The sun not only helps clear psoriasis symptoms in some cases, but also it makes your body produce more vitamin D.
Psoriasis and Vitamin D
Vitamin D can help reduce inflammation throughout your body. The nutrient, as well as the UV rays from light exposure, can help clear or prevent psoriasis plaques. Sunlight triggers your body to make the nutrient, which is beneficial to strong bones and immune function. Vitamin D is a nutrient found in few foods naturally.
A study published in the British Journal of Dermatology found that people with psoriasis tend to have low vitamin D levels, particularly in colder seasons. People with low levels of vitamin D can boost their levels by consuming:
- fortified milk and orange juice
- fortified margarine and yogurt
- egg yolks
- Swiss cheese
Sun therapy and diet are not the only ways to treat psoriasis with vitamin D. Talk to your doctor about using topical vitamin D ointments or creams to manage your symptoms.