The use of NB-UVB phototherapy in the treatment of psoriasis has been declining, partially due to the logistical barriers associated with its administration and with the advent of newer biologic and immunomod- ulating agents. However, the American Academy of Dermatology continues to recognize phototherapy as first line treatment for psoriasis due to a combination of its well-established effectiveness, inexpensive cost, and mild side effect profile compared to steroids . Recent studies show that phototherapy is at least as effective as current systemic therapies, with 70% to 80% of patients seeing at least a 75% reduction in their symptoms after 6 and 12 weeks of treatment respectively . Several immunosuppressive therapies are approved for management of psoriasis with extensive body surface area involvement or debilitating symptoms. These include methotrexate, anti TNF-alpha inhibitors, calcineurin inhibitors, and inhibitors of IL-17 and IL-23. While NB-UV phototherapy can be effective as monotherapy or in combination with some of these medications, the use of phototherapy alone offers cancer patients an opportunity to avoid immunosuppressive agents which could potentially lead to poorer outcomes and impair the durable benefits of ICIs.
The contrasting outcomes in two patient case report with psoriasiform reactions suggests other variables impacting response to NB- UVB phototherapy. Patient 1 had an excellent response to phototherapy, but notably had a lower pre-treatment TBSA involvement than patient 2. In a larger cohort, it would be worthwhile to investigate the possible surface area dependence or Common Terminology Criteria for Adverse Events (CTCAE) — grade toxicity dependence in correlation with response to NB-UVB phototherapy. Other major differences between the cases were the pre-existing psoriasis diagnosis and pustular involvement in patient 2. The severity of the symptoms was more pronounced and rapidly progressive in Patient 2, which necessitated next line treatment without an adequate trial of phototherapy. At this time, current recommendations report that NB-UVB phototherapy is appropriate for generalized plaque and guttate psoriasis (Elmets et al., 2019). However, future studies are warranted to determine which types of patients with ICI-induced psoriasis and disease severity benefit more from this treatment.
While the outcomes of patients successfully treated with NB-UVB phototherapy are promising, this treatment is not free of challenges. Therapy generally requires frequent visits to a clinic capable of providing UV light, which can be both logistically and financially challenging for patients. As seen in our case report, NB-UVB phototherapy may not be effective as monotherapy for severe cases of psoriasis. Side effects include erythema, folliculitis, blistering, and pruritus . Long term complications include the theoretical risk of melanoma and non-melanoma skin cancers. To date, there is limited studies evaluating the efficacy of NB-UVB phototherapy in the following disease subtypes: pustular, inverse, erythrodermic, and palmoplantar psoriasis. Phototherapy should be avoided in patients with photosensitive disorders, such as xeroderma pigmentosa, and be used with caution in patients with recurrent oral herpes simplex virus infection. Of note, NB-UVB phototherapy is generally considered safe in patients taking photosensitizing medications . Beyond the limitations mentioned, phototherapy is a viable option to be considered for psoriatic skin toxicity from ICIs especially those who are unable to tolerate or become refractory to steroid therapy. (NEXT: Natural Treatment to Get Rid Of Psoriasis at Home)
Originally published at https://fastway4you.com on October 16, 2020.
