The Journal of the American Academy of Dermatology recently published joint guidelines on ultraviolet light-based therapies for patients with psoriasis. 

The guidelines from the American Academy of Dermatology and the National Psoriasis Foundation released the joint guidelines were based on findings from existing literature in PubMed and MEDLINE databases published between January 2008- December 2017. 

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“NB-UVB refers to wavelengths ranging from 311 to 313 nm, which are widely used for the treatment of generalized plaque psoriasis,” Craig A. Elmets, MD, from the University of Alabama, and colleagues wrote in the study. “The starting dose for NB-UVB therapy can be based on skin phototype or minimal erythema dose (MED).”

Elmets and colleagues recommend patients receive patient two to three times a week, however, they note that treatment volume higher than three times per week could result in a greater risk of UV-induced erythema.  

Psoriasis plus UVA (PUVA) resulted in faster clearance with less treatment than with NB-UVB (12.7 treatments, and 49.2 days for PUVA compared with 16.4 treatments and 65.6 days for NB-UVB), according to comparative studies. 

According to the guidelines, a retrospective cohort study of 293 patients with psoriasis treated with various types of phototherapy at a single center showed that a majority of patients treated with NB-UVB (79.7%) achieved a good (60%-80% skin clearance) or excellent (80%-100% skin clearance) response.

Though more effective, oral PUVA causes a higher rate of adverse effects, according to Elmets and colleagues.

According to the researchers, Oral retinoids are effective when used in conjunction with NB-UVB and decrease the number of treatments and total UVB doses required. 

Cyclosporine treatment is also recommended due to its efficacy in the treatment of psoriasis. 

Combination treatment with NB-UVB and certain biologics is also supported by the researchers in cases in which monotherapy with either treatment modality is inadequate. 

While NB-UVB is safe and well-tolerated, overall, safeguards and cautionary implementations are recommended. Eye protection and genital shielding are recommended in all patients during phototherapy sessions. 

Photocarcinogenesis is another potential concern of the researchers.  While there are few prospective studies assessing the risk of skin cancer in patients with psoriasis treated with NB-UVB, Elmets and colleagues recommend that physicians use caution when prescribing NB-UVB for patients with a history of melanoma, multiple nonmelanoma skin cancers, arsenic intake, or exposure to ionizing radiation. 

“In addition to medication, treatment with light waves has proven to be an effective and largely safe intervention that can lead to significant improvement in—or even complete clearance of—associated psoriatic skin lesions,” the researchers wrote.