Phototherapy's Role in the Shifting Spectrum of Psoriasis Care

Though biologics and other new modalities may receive significant media attention in the treatment of psoriasis, a large majority of patients rely on “traditional” therapies. These include topical and systemic agents that have been available for decades. One of the keystones of psoriasis treatment is phototherapy. Though its efficacy has long been recognized, the practical challenges of phototherapy have rendered it a far-fetched possibility for some practices. Historically, entire rooms in dermatology practices were required for phototherapy machines. Moreover, generally low reimbursement rates have translated to relatively few practices offering the intervention, which forces patients to drive long distances for treatments, typically more than once per week.

Given these hurdles, phototherapy is being pushed to the fringe of psoriasis treatment. It has fulfilled the role of a niche treatment in the scope of psoriasis treatment. And yet, from a clinical standpoint, phototherapy remains one of the most reliable and effective therapies available. Additionally, recent advances regarding the delivery of UV light have made the procedure more accessible for certain types of psoriasis. Ahead, I will examine the role that phototherapy can still play in the treatment of psoriasis in the modern clinic.

Broadband, Narrowband, and PUVA

Given how long phototherapy has been in use for the treatment of psoriasis, new research on the treatment is not terribly common. Nevertheless, several recent review studies offer perspective on current standards and directions in care.

A recent review assessing the use of Narrowband UVB (NB-UVB) therapy in dermatology found that the efficacy of NB-UVB phototherapy compares favorably with other available phototherapy options and that its efficacy is further augmented by a number of topical and systemic adjuncts.¹ While the long-term safety of NB-UVB phototherapy remains to be fully elucidated, the investigators noted that the available data now suggest that it is safe and well-tolerated.

Beyond NB-UVB, support still remains for broadband UVB as well as Psoralen plus UVA (PUVA) in certain capacities. In a recent study, investigators examined broadband UVB versus PUVA for plaque-type palmoplantar psoriasis.² Specifically, they conducted a retrospective non-randomized cohort study comprised of 248 patients with palmoplantar psoriasis treated at a phototherapy center during 2010-2012, with 122 receiving BB-UVB and 126 receiving PUVA treatment. The authors noted that about 30 percent and 42 percent percent had complete remission in the UVB and PUVA groups, respectively. Additionally, 24 percent and 47 percent of patients responded partially and 47 percent and 11 percent patients did not improve with BB-UVB and PUVA, respectively. The odds ratio for remission was 7.9, while duration of remission was 21.9 plus or minus 1.34 months for PUVA and 16.75 plus or minus 1.83 months for BB-UVB, according to the results.

The authors concluded that both broadband UVB and PUVA are beneficial therapeutic options for palmoplantar psoriasis, but that PUVA is the superior modality, having yielded a better and more extended response. However, they observed that broadband UVB represents a feasible alternative in patients with milder disease or possible contraindications for PUVA.²

Targeted Phototherapy and Home-based Options

A relatively newer innovation in the scope of phototherapy has been the development of targeted treatments. In particular, the excimer laser (XTRAC, Mela Sciences) has emerged as a useful modality for patients with localized psoriasis. Although it is limited in treatment area and efficacy, one way of maximizing excimer laser treatment is to combine it with topical therapies. A recent study assessed the efficacy of a novel combination the 308nm excimer laser and clobetasol propionate spray and calcitriol ointment for the treatment of moderate to severe generalized psoriasis.³ In the 12-week study, patients with moderate to severe psoriasis received twice weekly treatments with a 308nm excimer laser combined with clobetasol proprionate twice daily for a month followed by calcitriol ointment twice daily for the next month. Of the 30 patients enrolled, 83 percent achieved PASI 75, while there was an estimated 3.6 percent decrease in PGA. The investigators concluded that the combination of excimer laser with alternating clobetasol and calcitriol application is a promising combination for the treatment of moderate to severe generalized psoriasis.

Another recent advance in this spectrum is the development of home phototherapy. Having been the subject of much speculation for many years, home phototherapy is a pristine concept that remains largely unproven in real-world medicine. In fact, the potential for removing the great inconvenience many patients must undergo for traditional phototherapy is enough to warrant interest, but the logistics have proven difficult until now. A recently published British review study looked at home phototherapy experiences over the last 10 years.⁴

The authors point out that previous research in this area have found phototherapy to be associated with a lower burden of treatment and increased patient satisfaction. The authors single out cases in which home phototherapy has been shown to be a viable option based on strong evidence and effective service models in places such as The Netherlands. However, although the limited evidence thus far is compelling for the use of home phototherapy, whether it offer a model for service sustainability and economic effectives remains a mystery that will hopefully be elucidated in due time.

Deserving Its Place

Continued research indicates that phototherapy deserves its place within the psoriasis treatment spectrum. We have also learned that phototherapy may not be as logistically challenging as previously thought. Roughly 70 percent of all patients receiving NB-UVB treatments three times per week are clear after 12 weeks, and about 70 percent of those patients remain clear for another six months. That means that roughly half of all patients on NB-UVB therapy do very well with it.

Prior to initiating phototherapy, it is first important to consider scalp involvement and/or arthritic symptoms, as these may require different treatments. It is also essential to assess skin type and thickness of plaques to determine if concomitant treatment (i.e. acetretin or PUVA) would be more efficacious.

Phototherapy (particularly NB-UVB therapy) presents a reliable option for many patients with psoriasis, particularly those with severe psoriasis with a low tolerance for risk. Moreover, the development of newer modalities offers us additional opportunities to bring this modality to patients who might benefit from it. n

Jerry Bagel, MD is Director of the Psoriasis Treatment Center of Central New Jersey.

1. Sokolova A, Lee A, D Smith S. The Safety and Efficacy of Narrow Band Ultraviolet B Treatment in Dermatology: A Review. Am J Clin Dermatol. 2015 Sep 14.

2. J Dermatolog Treat. 2015 Oct 20:1-3. [Epub ahead of print]

3. Levin E, Nguyen CM, Danesh MJ, Beroukhim K, Leon A, Koo J. An open label pilot study of supraerythemogenic excimer laser in combination with clobetasol spray and calcitriol ointment for the treatment of generalized plaque psoriasis. J Dermatolog Treat. 2015 Sep 28:1-4.

4. Hung R, Ungureanu S, Edwards C, Gambles B, Anstey AV. Home phototherapy for psoriasis: a review and update. Clin Exp Dermatol. 2015 Dec;40(8):827-33.

Overcoming Challenges in Topical Psoriasis Care

Watch Dr. Bagel and Neil J. Korman, MD, PhD discuss topical treatment options for palmar plantar psoriasis and the combined use of topical corticosteroids with phototherapy in the latest episode of the video series Clinical Conversations, available at DermTube.com/ClinicalConversations. Dr. Bagel and Dr. Korman also address alternative topical agents like topical immunomodulators.