A Mainstay in Psoriasis Treatment, Phototherapy Remains Relevant
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Psoriasis treatment options have come a long way, but phototherapy, one of the oldest treatments around, is still a mainstay in many dermatologists’ offices offering safe, effective management of plaque psoriasis.
First introduced in 1903, office-based phototherapy is used in multiple dermatologic conditions. While it has evolved and new techniques have been developed, the basic idea of phototherapy has not changed much in more than a century. Ultraviolet A or ultraviolet B radiation with different wavelengths — narrowband UVB, broadband UVB, UVA1 and psoralen (either by mouth or applied topically) UVA (PUVA) — are used, as well as excimer laser, a method for rapid delivery of localized UVB.
“Phototherapy calms down the skin’s immune system. UV exposure is probably one of the oldest treatments we have for psoriasis,” Steven R. Feldman, MD, PhD, professor of dermatology, pathology and social sciences and health policy at Wake Forest School of Medicine in Winston-Salem, North Carolina, said. “In biblical or pre-biblical times when lepers were sent into the desert and their skin got better, I suspect what was happening is that psoriasis was being treated with phototherapy from sun exposure.”
Although there are many new systemic psoriasis treatments available, phototherapy is still a popular choice for many patients and dermatologists who continue to offer a comprehensive standard of care.
Who is right for phototherapy?
Nearly any patient with psoriasis is eligible for phototherapy treatment, but those with severe disease are more likely to need it.
“Patients best suited would be the ones who have fairly extensive lesions,” Henry W. Lim, MD, former chair of the department of dermatology at Henry Ford Health System in Detroit, said. “General phototherapy, or total body phototherapy, is for patients with extensive lesions covering 20% to 30% of body surface. For patients with very localized disease resistant to topical treatment, localized phototherapy using excimer laser is very helpful.”
For pediatric patients, who may not be good candidates for systemic treatment, phototherapy offers an alternative that is safe and effective.
“For pediatric patients, parents are often hesitant to put their children on something like a biologic or a stronger medicine. I find that kids do really well with the treatment, and it has very minimal risks or adverse events,” Christina Cammarata, PA-C, a physician assistant at HMGS Dermatology in Marlton, New Jersey, said.
Lim agreed, saying as long a child can follow instruction and wear the goggles for safety, it is a safe option for young patients. Feldman says he has a parent stay in the phototherapy unit with young children to assure the safety protocols are followed.
Additionally, many elderly patients at Cammarata’s practice opt for phototherapy over biologics or other systemic medications, as do patients who have a history of other medical conditions that preclude them from being on immunosuppressive medications.
“I often find that patients who choose phototherapy would prefer not to go on systemic medications or prefer a more natural approach to treating their psoriasis,” Cammarata said. “Some also have contraindications to biologics. Additionally, it is safe for pregnant patients.”
A declining trend
With the innovation in biologic medications, phototherapy is not used as often as it once was. A 2021 study published in the Journal of Dermatology Treatment estimated statistically significant decreasing trend between 2015 and 2018.
“It’s used a lot less than it used to be. Many insurers cut back on reimbursement, which led to less use. The copay structure with copays at every visit, discouraged its use and then the availability of really extraordinarily safe and effective injectable treatments cut back on the need for phototherapy,” Feldman said.
Despite its decline, however, experts argue that the need for phototherapy is still growing.
“It’s obviously not used as much as it was 30-plus years ago, but it has a valuable role,” Elisabeth G. Richard, MD, assistant professor of dermatology at Johns Hopkins University School of Medicine in Baltimore, said.
Many studies have shown efficacy of more than 80% of psoriasis patients treated with narrowband UVB phototherapy achieving disease remission.
Challenges to treatment
Phototherapy generally entails multiple visits to a dermatologist office each week. While the visits are short — normally around 15 minutes in the phototherapy booth — the time commitment, paired with insurance coverage concerns, can be the biggest challenges for patients.
Most insurance companies cover phototherapy treatment; however, many include copays for every specialist visit, and these can add up over weeks of treatment.
“There’s quite a variability as to what the commercial insurances expect patients to pay out of pocket each time. That is very plan specific and can be a limiting factor to compliance,” Richard said. “And time is a factor. In-office phototherapy requires coming to the office two or three times a week. You’re in and out of the office fairly quickly, but it does require gas and time.”
In addition, access can be difficult in some places, specifically rural areas, according to Lim.
“Some areas of the country there is no phototherapy unit,” he said. “Assuming there is a unit, patients would have to get there, and it is a significant commitment on their time.”
Phototherapy as adjunctive treatment
Narrowband UVB and PUVA are effective on their own, but used in conjunction with other drugs increases efficacy.
“Phototherapy can be very effective all by itself. But sometimes the legs from the knee to the ankle don’t clear up as fast as the torso does, so you could have patients on topical therapy on any bothersome spots,” Feldman said. “If lesions are very thick, using a topical tar medicine along with light (but not right before as the tar may block the UV) is probably more effective than light alone.”
A 2022 network metanalysis of 32 studies including 2,120 psoriasis patients showed PUVA combined with calcium/vitamin D derivatives and UVB combined with adjuvant therapies had superior effect compared with monotherapy of either phototherapy option.
Other adjuvant therapies such as acitretin, methotrexate and biologics can also be used.
“Acitretin helps to thin down the lesion, so for patients with hyperkeratotic lesions it is a very useful agent for phototherapy,” Lim said. “Sometimes patients with biologics will also use phototherapy, especially in the beginning, to help bring the activity down.”
Methotrexate use can increase photocarcinogenicity, so must be used more carefully, but can still be helpful, he added.
Safety profile
Adverse events with phototherapy are rare, which is one of the reasons it remains a constant in the skin care armamentarium.
Side effects can include erythema, pruritus, hyperpigmentation and blistering, all of which are generally short-lived, as well as photo conjunctivitis or photokeratitis, which is why eye protection is mandatory.
“The most common side effect of therapy is UVB induced burning and resembles a sunburn. This typically occurs when patients reach higher doses, and when this occurs we adjust the dose accordingly,” Cammarata said.
For patients with darker skin types, hyperpigmentation can be an issue, but generally not one that would preclude them from receiving treatment.
“Patients with skin type III to VI, when the lesion is resolved, could be left with a significant hyperpigmentation,” Lim said. “This is something that we have to inform patients about. Most accept it as long as you explain it to them well.”
The future of phototherapy
Development of the excimer laser has allowed phototherapy to be used in more localized areas than previous phototherapy units, growing the number of patients who can benefit from treatment.
“In a light box you’re treating the whole body at once, but for people who just had a couple of spots, the development of devices to target those areas quickly and efficiently has an advantage,” Feldman said.
At-home phototherapy units are another advancement in expanding phototherapy treatment, especially for patients with busy schedules or those who cannot make office appointments two to three times per week. An ongoing coordinated by the University of Pennsylvania, the LITE study, is designed to compare the effectiveness, safety and duration of treatment response in office vs home-based phototherapy for patients with psoriasis.
Whether at-home or in the office, continuing to offer phototherapy as a treatment option is necessary, according to Richard.
“If you’re going to treat psoriasis, I think you need to offer all of the options as a comprehensive therapeutic menu,” she said.
- References:
- Branisteanu DE, et al. Exp Ther Med. 2022;doi:10.3892/etm.2022.11184.
- Oule A, et al. J Dermatolog Treat. 2021;doi: 10.1080/09546634.2021.2019660
- Housman TS, et al. J Am Acad Dermatol. 2002;doi:10.1067/mjd.2002.120451.
- Li Y, et al. Ann Med. 2022;doi:10.1080/07853890.2021.2022187.
- For more information:
- Steven R. Feldman, MD, PhD, can be reached at Wake Forest School of Medicine, 4618 Country Club Road, Winston-Salem, NC 27104. Email: sfeldman@wakehealth.edu.
- Henry W. Lim, MD, can be reached at Henry Ford Medical Center, 3031 West Grand Blvd., Suite 800, Detroit, MI 48202. Email: HLIM1@hfhs.org.
- Christina Cammarata, PA-C, can be reached at HMGS Dermatology, 100 Brick Road, #306, Marlton, NJ 08053. Email: cmcammarata@ hmgsderm.com.
- Elisabeth G. Richard, MD, can be reached at Johns Hopkins at Green Spring, 10753 Falls Road, Suite 355, Lutherville, MD 21093. Email: ericha16@jhmi.edu.