One of the realities we live with at Amjo is that many derms look at UV Phototherapy as a last resort. The typical derm would prefer to prescribe biologics and other ointments and salves, many of which expose the patient to higher risks than UVB Narrowband Phototherapy. The article below is one of the few that I’ve come across recommending UV Phototherapy.
The American Academy of Dermatology’s latest guidelines on the management of psoriasis and psoriatic arthritis focus on phototherapy.
Despite therapeutic advances in recent years, phototherapy remains an important treatment option for patients with psoriasis, according to Dr. Alan Menter, chairman of the division of dermatology at Baylor University Medical Center in Dallas, and his associates.
One area of ongoing investigative research compares narrow-band ultraviolet B light (NB-UVB) with psoralen–ultraviolet A light (PUVA) treatment. While PUVA, usually with oral 8-methoxypsoralen, seems to result in more rapid clearance of psoriasis plaques with fewer adverse events, more research with larger numbers of patients needs to be done.
General Principles
AAD’s phototherapy guidelines recommend that all patients undergo a complete history and physical before undertaking phototherapy for psoriasis. Among those who should not be treated with phototherapy are patients with lupus or xeroderma pigmentosum.
Careful screening is required before undertaking phototherapy in patients taking photosensitizing medications; patients having a photosensitivity disorder, a history of melanoma, atypical nevi, multiple risk factors for melanoma, or multiple non–melanoma skin cancers; or patients who are immunosuppressed as the result of organ transplant, according to Dr. Menter, chair of the AAD Psoriasis Work Group, and his associates.
UVB Phototherapy
UV radiation ranging from 254 nm to 313 nm producing suberythemogenic exposure leads to significant improvement of psoriasis. NB-UVB, which involves use of a bulb that emits light between 311 and 313 nm, has been proved superior to the broadband (BB)-UVB at both inducing and maintaining remission. NB-UVB seems to have immunosuppressive effects that are useful in the treatment of psoriasis.
The guidelines include tables outlining previously published, “well-accepted” dosing regimens for both BB- and NB-UVB (J. Am. Acad. Dermatol. 2009 [doi 10.1016/j.jaad.2009.08.026]).
Burning is as common with NB-UVB as with BB-UVB. Data from murine studies suggest that NB-UVB is two to three times as carcinogenic as BB-UVB. However, given that its higher efficacy results in less exposure, NB-UVB may not pose more significant long-term risk of carcinogenesis.
While pregnant women may be at increased risk for melasma from NB-UVB, it is not contraindicated in this population. It should be used as the first-line therapy in pregnant women with plaque and guttate psoriasis, wrote Dr. Menter. Judicious use of NB-UVB should be considered as a second-line therapy in children who do not benefit from topical therapy.
UVB Combination Therapy
There are no randomized studies on the benefit of applying a topical agent in preparation for UVB phototherapy, despite the fact that doing so is a mainstay of phototherapy. The data are mixed on the efficacy of combining the vitamin D analogue calcipotriol with phototherapy. The greatest benefit is seen when it is used in combination with NB-UVB. However, it should be applied after phototherapy to avoid degradation from exposure to UV radiation, according to the guidelines.
The use of methotrexate in combination with phototherapy seems to speed clearance. However, psoriasis may flare once methotrexate is discontinued. Use of retinoids in combination with UVB speeds the therapeutic response, lowering the total exposure to UV radiation, although clinicians have been unwilling to avail themselves of this therapeutic option, according to the authors.
Dr. Menter served on the advisory board of and was a consultant, investigator, and speaker for numerous pharmaceutical companies as have the other 12 members of the work group.
This article can be found in the December 2009 issue of SKin and Allergy News. It was written by Sally Koch Kubetin
