Ultraviolet therapy can be done at home using equipment that can be purchased through several distributors in the United States. If you are thinking about starting a program of ultraviolet-B therapy at home, first meet with your dermatologist to see if this is an appropriate option for you. If you are a suitable candidate for this therapy, your dermatologist will provide you with a prescription for the light panels.
Home therapy must be carefully monitored so that excessive exposure to ultraviolet light (which can increase your risk of skin cancer) is avoided, and to ensure the proper dosage is chosen and used to avoid burning.
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| UVB Light Psoriasis |
Home therapy is rare in North America because, understandably, many dermatologists are reluctant to prescribe a treatment that is difficult to monitor and that has potential risks. Generally, only those who live far from treatment centers use home phototherapy. In addition, home phototherapy units are quite expensive.
Narrow-Band Ultraviolet-B Therapy
Also known as selective UVB phototherapy, narrow-band ultraviolet-B (NB-UVB) light therapy is a newer phototherapy method that can offer safer and more effective results in the treatment of psoriasis. Ultraviolet-B ranges from 290-320 nanometers in wavelength. Special narrow-band UVB lamps emit a very narrow band of high intensity light at 311--312 nanometer wavelengths.
The major advantage of this therapy is that it eliminates much of the high-energy, shorter ultraviolet-B wavelengths that have been attributed to burning, premature aging, and increased risk of skin cancers. Initial research has found that narrow-band ultraviolet-B is more effective and can keep the psoriasis clear for longer, even after the therapy is discontinued. Recent studies show that in some patients, narrow-band ultraviolet-B provides faster clearance with fewer treatments. For most, approximately 30-35 treatments could be required to obtain clearance; however, for some, it could be fewer.
Narrow-band ultraviolet-B can also be used in combination with topical treatments such as corticosteroids, calcipotriol, anthralin, tar, and tazarotene gel to improve psoriasis.
Psoralen Plus Ultraviolet-A Light Therapy
When used alone, ultraviolet-A is only minimally effective in treating psoriasis. However, when combined with topical application or ingestion of psoralen, ultraviolet-A can have a significantly greater effect in clearing psoriasis. Psoralen plus ultraviolet-A (PUVA) involves administering psoralen prior to exposing skin to ultraviolet-A light. Psoralen makes the skin more sensitive to the effect of ultraviolet light, and as a result improves the effect of ultraviolet-A in the treatment of psoriasis.
Dr. Parish, Dr. Fitzpatrick, and colleagues at Harvard Medical School first reported the use of PUVA in 1974. In their initial clinical experiment, a patient ingested psoralen, then half the body was covered and the patient received ultraviolet-A on the opposite side. The patient showed clearance of psoriasis on the side that received the combination, but no improvement on the side that was protected from UVA. This indicated that the combination of psoralen and ultraviolet-A was essential for obtaining the beneficial effect.
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| UVB Light Psoriasis |
After taking psoralen, you need to wear protective sunglasses for twenty-four hours because there is a possible risk of developing cataracts (abnormalities in the lens of the eye, causing blurry vision or decreased vision). To date, an increase of cataracts has not been reported in PUVA patients treated with careful eye protection.
Certain patients should not have PUVA therapy, such as those with medical conditions that make them more sensitive to the sun (e.g., systemic lupus erythematosus). Also, if you are unable to stand for long periods of time, are pregnant, or are unable to comply with treatment, you should not use PUVA. To find out more, you can check out UVB Light Psoriasis.