Based on the available literature, the American Academy of Dermatology and the National Psoriasis Foundation published joint guidelines on ultraviolet light-based therapies for the treatment of psoriasis.
Here, Healio Dermatology summarizes the joint findings on the risks and benefits of narrowband ultraviolet light B (NB-UVB) treatment.
NB-UVB refers to wavelengths from 311 nm to 313 nm and is typically used to treat generalized plaque psoriasis, according to co-chair of the guidelines Craig A. Elmets, MD, from the University of Alabama, and colleagues.
The researchers recommended treatment two or three times a week and warned that a greater frequency results in minimal benefit and may expose a patient to a higher total dose of UVB radiation, leading to a greater risk for UV-induced erythema. Before treatment, a thin layer of emollient such as petrolatum should be applied to increase effectiveness and reduce erythema.
Based on comparative studies, psoralen plus ultraviolet A (PUVA) resulted in faster clearance with less treatment than NB-UVA, according to the researchers; however, oral PUVA has a higher rate of adverse effects.
“Although PUVA monotherapy was more effective than NB-UVB in many studies, superior short-term and long-term safety, simplicity and lower cost favor NB-UVB as the preferred treatment for plaque psoriasis,” they wrote.
If patients are unable to travel to a phototherapy center, home NB-UVB units can be considered.
“The burden of treatment was significantly lower, and patients were happier with their treatments when the UV light was delivered in the home phototherapy setting,” Elmets and colleagues wrote.
The data are mixed regarding the use of topical calcipotriol with NB-UVB.
“The apparent lack of an added effect of calcipotriol might be due to the fact that vitamin D analogues are degraded by exposure to UV radiation,” the researchers wrote.
Topical psoralens have also been studied in conjunction with NB-UVB, but researchers determined there is insufficient evidence to recommend the combination.
The use of methotrexate as a systemic adjunct to NB-UVB is not supported by the literature.
Oral retinoids have a beneficial effect with NB-UVB, decreasing the number of treatments and UVB dose.
Cyclosporine is often used in the treatment of psoriasis, but simultaneous use with NB-UVB is contraindicated due a higher risk for skin cancer.
The use of certain biologics is also supported as combination therapy with NB-UVB, and researchers recommended its use for cases in which monotherapy with either treatment is insufficient.
Ninety-five percent of patients who were treated with NB-UVB three times per week along with adalimumab 40 mg every other week achieved a 75% improvement in Psoriasis Area Severity Index score (PASI 75) at week 12, with 65% of patients maintaining PASI 75 at week 24, according to researchers.
Apremilast has been used with phototherapy, and the researchers supported this combination.
Concerns remain about the long-term risk for photocarcinogenesis with combined NB-UVB and PUVA therapy, so the researchers concluded that there is insufficient evidence to recommend this treatment.
As for risk management, the researchers recommend genital shielding in all patients undergoing phototherapy sessions to reduce the risk for genital skin cancer, as well as goggles for eye protection to reduce the risk for UVB-related ocular toxicity.
The risk for photocarcinogenesis is correlated with the number of treatments received.
“Because of the theoretical possibility of this risk, physicians should use caution in prescribing NB-UVB for patients with a history of melanoma, multiple nonmelanoma skin cancers, arsenic intake or exposure to ionizing radiation,” the researchers wrote.
NB-UVB is considered safe in pregnancy, although it may lead to a degradation of folate. Thus, women of childbearing potential should supplement with folate 0.8 mg daily. – by Abigail Sutton
Disclosures: Elmets reports he served as a consultant for Ferndale Laboratories; a consultant and advisory board member for Vertex Pharmaceuticals; a principal investigator for the California Association of Winegrape Growers; an investigator for Elorac, Idera Pharmaceuticals, Kyowa Hakko USA and Solgenix; a data safety monitoring board member for Astellas Pharma US and Leo; and a stockholder for Medgenics, Aevi Genomic Medicine and Immunogen. Please see the study for all other authors’ relevant financial disclosures.