(LifeWire) - I knew my psoriasis had gotten out of hand when no amount of prescription ointments could heal all my red, scaly skin patches. I'd do almost anything to improve it, including visiting my dermatologist three times a week.
This is often the case with people, like me, who then opt for phototherapy -- the use of ultraviolet (UV) light rays, several times a week, to treat the thick, silver-scaled patches of itchy, inflamed skin (lesions) associated with psoriasis. The UV radiation slows the rapid turnover of skin cells that defines all forms of psoriasis.
Phototherapy isn't usually the first treatment choice for people with psoriasis, which make up about 2% of the American population. Prescription topical creams and ointments are more convenient -- and less expensive. But they may become less effective as plaques grow resistant. Phototherapy can be a suitable next step in many cases.
Typically, people with psoriasis will have a moderate or severe case (defined as anywhere from 20 to 100% psoriasis skin coverage) before phototherapy is in order. The considerations for treatment are as much practical as medical. Phototherapy sessions generally take place in a doctor's office and require two or three visits a week for several months or more before improvement is seen, as evidenced by gradually fading patches.
It's a major commitment of time and money; even patients with health insurance generally need to cover insurance copayments for each session. Over the months, those co-pays can add up. According to a 2006 study in the journal Managed Care Interface, the estimated out-of-pocket expense for a single patient's phototherapy is roughly $1,800.
Sometimes phototherapy can be done at home using a smaller UV light, targeting specific areas of the body, such as the hands or feet, potentially cutting the cost somewhat. But it's still a medical procedure that must be prescribed and monitored by a physician. Ask your dermatologist if home phototherapy might be an option for you.
Different forms of phototherapy are available, categorized by the wavelength of UV light used. UV light in the so-called A range (UVA) has a longer wavelength than that in the B range (UVB), both of which are found in natural sunlight.
The main options for phototherapy are:
PUVA
P stands for psoralen, a medication used along with UVA phototherapy that makes the skin more sensitive to light. PUVA has been proven to clear psoriasis plaques in more than 85% of individuals using it for several months or more, and the results last for several months or longer.
UVB
Phototherapy with UVB light can be used alone or in combination with other topical or systemic psoriasis medications. An average of 30 UVB treatments is needed to achieve maximum results; as with PUVA, the results can last for months or longer. There are two types of UVB therapy: broadband, which is an older form of treatment, and narrowband, which is newer and shown to be more effective.
Lasers
Only used for psoriasis treatment within the last few years, lasers use a specific wavelength of UVB to target psoriasis plaques. Because the beams are small, this form of phototherapy works best for localized, mild to moderate psoriasis.
Words of Caution
Phototherapy, as with most medical treatments, carries some risks and potential side effects. The most obvious is skin cancer, as the treatment relies on UV radiation. People with psoriasis are advised to use sunscreen on any non-affected skin areas when having phototherapy treatment and to get an annual skin cancer check with the dermatologist. Phototherapy also carries the risk of skin aging.
Scientists have established that long-term PUVA therapy (more than 150 sessions) modestly increases one's risk of developing nonaggressive, easily removed skin cancers. Because UVA rays penetrate more deeply than UVB rays, there's a greater risk of cell damage.
Another potential problem is sunburn, which can not only cause lesions to itch intensely, but trigger flare-ups in some individuals. Certain prescription and over-the-counter drugs can increase the risk of sunburn, including birth control pills and some antibiotics, antidepressants, antihistamines and high blood pressure medications. Make sure that your doctor knows the medications you take regularly before you start phototherapy.
Sources:
"Home Phototherapy." Psoriasis.org. Dec. 2005. National Psoriasis Foundation. 13 May 2008. <http://www.psoriasis.org/treatment/psoriasis/phototherapy/home.php>.
"Lasers." Psoriasis.org. Dec. 2005. National Psoriasis Foundation. 13 May 2008. <http://www.psoriasis.org/treatment/psoriasis/phototherapy/lasers.php>.
Lee, E. "UVB Phototherapy and Skin Cancer Risk: A Review of the Literature." International Journal of Dermatology 44. 5 May 2005. 355-60. 13 May 2008. <http://www.ncbi.nlm.nih.gov/pubmed/15869531?dopt=Abstract>.
"Phototherapy: Tips for Your Protection and Comfort." Psoriasis.org. December 2005. 13 May 2008. <http://www.psoriasis.org/treatment/psoriasis/phototherapy/tips.php>.
"PUVA." Psoriasis.org. December 2005. National Psoriasis Foundation. 13 May 2008. <http://www.psoriasis.org/treatment/psoriasis/phototherapy/puva.php>.
Simpson, J.F. "Would Elimination of Copayments for Phototherapy Decrease the Cost of Treating Psoriasis with Systemic Biologics? A Cost Analysis." Managed Care Interface 19.6 June 2006 39-43. 13 May 2008. <http://www.ncbi.nlm.nih.gov/pubmed/16892660>.
"UVB Phototherapy." Psoriasis.org. Dec. 2005. National Psoriasis Foundation. 13 May 2008. http://www.psoriasis.org/treatment/psoriasis/phototherapy/uvb.php.
