The World of UV Phototherapy

Posts Tagged ‘PUVA’

Bumped Up (2010-03-08)

In the begining “Yes” but now “Absolutely not!” The answer is no. Tanning beds generate UVA or Long Wavelength UV. UVA penetrates the skin very deeply while the shorter wavelengths of UVB do not. UVA is used in photoherapy when combined with a Psoralen drug and the therapy is called PUVA.

In tanning bed antiquity, the UVB content was much higher. Today, in the USA, the FDA has regulated that the UVB content in tanning beds must be very low! Because of regulations, tanning beds produce only 4.2% to 6.5% UVB in the USA and typically 1% to 3% in Europe. To read the US FDA Regulations <Click Here>. The level of UVB radiation is in the following statement “Performance requirements–(1) Irradiance ratio limits. For each sunlamp product and ultraviolet lamp, the ratio of the irradiance within the wavelength range of greater than 200 nanometers through 260 nanometers to the irradiance within the wavelength range of greater than 260 nanometers through 320 nanometers may not exceed 0.003 at any distance and direction from the product or lamp. UVB is commonly defined as 280 to 320 nanometers.

Tanning Salons can be a risk for the typical consumer as the output from these beds can vary greatly from bed to bed and treatment/tanning times must be adjusted based on lamp power. When a bed is re-lamped and you are not told then a sunburn is very likely.

UVA wavelengths pass through the epidermis to the hypodermis Click on the image for a link to this photo's source.

Read this article http://www.pnas.org/content/101/14/4954.full which seems to indicate that UVA may be more dangerous than UVB. This is a complicated subject but it does appear that it is UVA that contributes to premature skin aging and is more likely to cause cancers of the skin.

UNDERSTANDING UV RAYS
“Most everyone is aware of the risks associated with UVB exposure, however there are real risks associated with UVA exposure including skin aging, DNA destruction and even skin cancer. Protecting your skin from UVA rays is just as important as protecting yourself against UVB rays.”  - A quote by Dr. Henry Lim, Vice President-Elect, American Academy of Dermatology and Chairman of Dermatology, Henry Ford Hospital, Detroit, MI.

Here’s another posting at this blog on the diferences twixt UVA and UVB. See PUVA vs UVB NARROWBAND.

Don’t be fooled by the non-medical advice of a tanning salon owner! Check with your dermatologist.

The full article publication is entitled “Efficacy of narrowband UVB vs. PUVA in patients with early-stage mycosis fungoides.” prepared by Ponte P, Serrão V, Apetato M. at the Department of Dermatology, Hospital dos Capuchos, Centro Hospitalar de Lisboa Central, Lisbon, Portugal.

Abstract:

The article concludes “Besides topical and systemic therapy, UVA1 radiation is a good option of treatment in various skin diseases. It is one of the first-line treatments for several sclerotic diseases and it often improves pruritus considerably.”

I came across this study during an internet search when a customer called me about the use of UVA1. I have to admit I was surprise by the fact that the use of UVA1 has shown some good results with atopic eczema, scleroderma and other challenges.

The authors say

The breakthrough came after 1988 when narrow-band UVB (NB-UVB) phototherapy was introduced for the treatment of psoriasis…

Narrow band UVB phototherapy in dermatology

AUTHORS: Sunil Dogra, Amrinder Jit Kanwar
Department of Dermatology, Venereology and Leprology, Postgraduate Institute of Medical Education & Research, Chandigarh, India

Full Article < Click Here >

The first report of the use of ‘phototherapy’ in the treatment of skin disorders dates from 1400 BC from India when patients with vitiligo were given certain plant extracts (whose active ingredients included psoralens) and then exposed to the sun. The real interest in the use of ultraviolet (UV) irradiation in the treatment of various skin diseases started in the 19th century when Niels Finsen received the Nobel Prize (1903) for his therapeutic results with UV irradiation in lupus vulgaris, the only dermatologist ever to be awarded one. This marked the start of modern phototherapy. It was used in thermal stations for the treatment of tuberculosis, in the treatment of leg ulcers in wartime, and various other skin diseases. It was a very long journey from the use of plant extracts and sun exposure to treat vitiligo to the use of oral psoralens and total body UVA-irradiation cabins (PUVA) to treat various skin diseases. In a landmark development, in 1974 Parrish et al reported the useful role of high intensity UVA tubes in combination with oral psoralens in the treatment of psoriasis leading to what is now known as PUVA therapy.

The history of UVB phototherapy is not as old as the history of photochemotherapy. Wiskemann introduced irradiation cabin with broad band UVB tubes in 1978 for the treatment of psoriasis and uremic pruritus. However, broad band UVB phototherapy was less efficient for treating psoriasis than PUVA and so never achieved popularity. The breakthrough came after 1988 when narrow-band UVB (NB-UVB) phototherapy was introduced for the treatment of psoriasis by van Weelden et al and Green et al.

When one is being treated with UVA, UVB or UVB Narrowband, it is mandatory that one protects one’s eyes from the ultraviolet rays. To work without eye protection is probably foolhardy. There is an article on this blog:

See http://www.uvbnarrowband.com/?p=679 for a discussion of treating the eyelids with UV. Remember, none of this medical advice, you must check with your doctor before treating your eyelids (Our Disclaimer: << Click Here >>

UV Blocking Goggles

Let’s first talk about eye protection during treatment. The recommendation is to always us a type of eye protection that protects the eye from UV rays coming from any or all directions. The prime choice is the use of UV Blocking Goggles. Goggles such as the ones shown to the left are typical and they do provide protection from all directions. These are a must << Click Here >>

Let’s talk about eye protection following treatment. Why talk about that? If you happens to be undergoing PUVA treatment ‘P’soralen and UVA light then the Psoralen increases your skin and EYE sensitivity to UV light. For 24 hours folowing treatment or as recommended by your doctor you will need eye protection.

Randomized double-blind trial of treatment of vitiligo: efficacy of psoralen-UV-A therapy vs Narrowband-UV-B therapy.

Yones SS, Palmer RA, Garibaldinos TM, Hawk JL.

Dip Der, FCD, Photobiology Unit, Second Floor, St John’s Institute of Dermatology, Division of Genetics and Molecular Medicine, Guys, King’s and St Thomas’ School of Medicine, King’s College, London SE1 7EH, England. yones5@yahoo.com

OBJECTIVE: To compare the efficacy of oral psoralen-UV-A (PUVA) with that of narrowband-UV-B (NB-UVB) phototherapy in patients with nonsegmental vitiligo. DESIGN: Double-blind randomized study. SETTING: Phototherapy unit in a university hospital. PATIENTS: Fifty-six patients with nonsegmental vitiligo. Interventions Twice-weekly therapy with PUVA or NB-UVB. MAIN OUTCOME

MEASURES: The change in body surface area affected by vitiligo and the color match of repigmented skin compared with unaffected skin were assessed after 48 sessions of therapy, at the end of the therapy course, and 12 months after the end of therapy.

RESULTS: The results in the 25 patients each in the PUVA and NB-UVB groups who began therapy were analyzed. The median number of treatments was 47 in the PUVA-treated group and 97 in the NB-UVB-treated group (P = .03); we suspect this difference was because of the differences in efficacy and adverse effects between the 2 modalities, such that patients in the NB-UVB group wanted a longer course of treatment. At the end of therapy, 16 (64%) of 25 patients in the NB-UVB group showed greater than 50% improvement in body surface area affected compared with 9 (36%) of 25 patients in the PUVA group. The color match of the repigmented skin was excellent in all patients in the NB-UVB group but in only 11 (44%) of those in the PUVA group (P<.001). In patients who completed 48 sessions, the improvement in body surface area affected by vitiligo was greater with NB-UVB therapy than with PUVA therapy (P = .007). Twelve months after the cessation of therapy, the superiority of NB-UVB tended to be maintained.

CONCLUSION: In the treatment of nonsegmental vitiligo, NB-UVB therapy is superior to oral PUVA therapy.

PMID: 17519217 [PubMed - indexed for MEDLINE]

Article Source <CLICK HERE>

Narrowband UVB was safer and more effective than PUVA for vitiligo therapy.

Phototherapy employing sunlight and plants that contain natural psoralens was first used for vitiligo thousands of years ago, and it continues to be a first-line treatment today. Investigators conducted a randomized, double-blind trial to compare two of the most popular forms of phototherapy for vitiligo in 50 patients with nonsegmental vitiligo who received either PUVA or narrowband UVB (NB-UVB) therapy (25 patients in each group).

After treatment (maximum, 144 sessions), subjects in both groups had significant reductions in the extent of vitiligo-involved body surface area. Although between-group differences were not statistically significant, improvement occurred more rapidly and tended to be greater with NB-UVB. After 48 treatments in patients who received that many sessions, the median percentage of improvement in affected body-surface area was slightly more than 20% in the PUVA-treated patients and more than 50% in the narrowband-treated group. The color of the repigmented skin matched excellently the color of uninvolved skin in all NB-UVB recipients but in only 44% of PUVA recipients. Erythema occurred more often with PUVA phototherapy than with NB-UVB therapy (in 96% vs. 68%, respectively). The PUVA recipients received a median of 47 treatments and the narrowband UVB patients, a median of 97; the authors suggest that this is because of the greater efficacy and fewer adverse effects experienced by NB-UVB recipients.

Comment: This study clearly demonstrates that for vitiligo repigmentation, NB-UVB is safer and more effective than PUVA. Other randomized, controlled trials have shown at least some efficacy with targeted phototherapy, topical and systemic steroids, topical calcineurin inhibitors, and calcipotriene combined with PUVA. A number of reports show success with surgical repigmentation procedures, as well. Although we are making progress in treating this vexing disease (especially with calcineurin inhibitors and phototherapy), we still have a long way to go. At best, 75% of patients respond, and in most instances, this response is only partial. A breakthrough in the management of this disease would be greatly welcomed by both patients and doctors. An accompanying editorial provides a nice evidence-based review of existing therapies for vitiligo.

— Craig A. Elmets, MD

Published in Journal Watch Dermatology June 1, 2007

PUVA is an older treatment method. It’s an acronym for “P”soralen and UVA. UVA is long wavelength ultraviolet and the upper layers of our skin are not affected significantly with UVA light as the long wavelengths penetrate quite deeply. To sensitize the skin a Psoralen is used either topically (rubbed on) or orally (swallow a pill or liquid). Psoralens taken internally can cause nausea, liver toxicity and other challenges. If you are prescribed PUVA then your doctor will do some blood tests to determine if liver toxicity could be a problem.

UVB Narrowband has several advantages over PUVA

• No Concurrent Drug Therapy such as Psoralen is needed.
• There much less risk of sunburn over UVB Broadband or PUVA
• Lower skin cancer risk
• No protective eyewear needed FOLLOWING exposure (Psoralens increase the eye’s sensitivity to UV and for 24 hours following treatment with PUVA
• Vastly reduced premature aging of the skin which is prevalent in PUVA.