Phototherapy for the Treatment of Psoriasis: When Is It the Right Choice?

This transcript has been edited for clarity. 

Tina Bhutani, MD, MAS, FAAD: Hi, everybody. My name is Tina Bhutani. I'm a board-certified dermatologist, practicing in San Francisco, California. I specialize in psoriasis and inflammatory skin diseases. 

Today, we are going to have a discussion about the role of phototherapy for the treatment of psoriasis. First, what is phototherapy? When would we use phototherapy? And what are some unique circumstances where phototherapy is our go-to treatment?

I'm very excited to be joined by my colleagues, Dr Mona Shahriari and Dr Jason Hawkes. Can I have you introduce yourselves? Mona, do you want to start? 

Mona Shahriari, MD, FAAD: Thank you so much, Tina, I'm really privileged to be here today. I'm Mona Shahriari. I'm an assistant clinical professor of dermatology at Yale University and the associate director of clinical trials at Central CT Dermatology Research. Just like you, I live and breathe inflammatory skin disease, in particular, psoriasis. I'm very happy to be here. 

Bhutani: Thank you. Jason? 

Jason E. Hawkes, MD, MS: Hi. Glad to be here and good to be with both of you again. I'm a medical dermatologist with a background in translational immunology and an interest in clinical trials and many of the inflammatory diseases. I really use everything for these patients with psoriasis as well as with other diseases, and I'm happy to have the conversation today. 

Bhutani: Awesome. Thank you both for joining us. In this day and age, we have many different therapies for psoriasis. Our toolbox is very full. Sometimes, it gets very difficult to make a decision. Which treatment do we pick for which patient? In this multitude of treatments, I think phototherapy is a little bit of a lost art. 

Today, I want to talk a little bit about what is phototherapy, the different types of phototherapies, and then, which patients would we choose phototherapy for. 

Mona, I'm wondering if you can start and tell us a little bit more about phototherapy and the types of phototherapies that you might utilize in your practice. 

Shahriari: Absolutely. I still consider phototherapy to be one of the safest treatments for inflammatory skin disease, in particular, psoriasis. The way it works is we use ultraviolet (UV) light to slow down the cell growth that's happening in psoriasis and decrease the inflammation in the skin. 

You can use it as monotherapy or in combination with topicals, orals, or even injectables for all severities of plaque psoriasis. When I think of the different types of phototherapies, there are the three main ones that come to mind. We have narrowband UVB, which is really the most common form of phototherapy. 

It uses that wavelength of 311 to 313 nm, which is the perfect wavelength to treat plaque psoriasis. We also have targeted phototherapy because there are some patients who might have smaller areas of plaque psoriasis, so they don't need their entire body treated like we do with narrowband. 

Lastly, I think of psoralen plus UVA therapy, or PUVA, as another treatment. That being said, I could go into it in more detail, but I feel like in the year 2024, PUVA doesn't have as much of a role because though it's much more effective than narrowband, I do think the side-effect profile makes it less desirable. 

Bhutani: I totally agree. Like you said, narrowband UVB is just so much more accessible than PUVA is. Although I, for example, love something like hand-foot PUVA for palmoplantar psoriasis for my patients. 

Jason, Mona just mentioned the side-effect profile for PUVA, but let's get back to narrowband also. How do you counsel your patients when you're talking to them about phototherapy? What do you tell them about the logistics of treatment, side effects, and what they should expect? 

Hawkes: When we're talking about phototherapy, we want to always set that up as one option among all the other available treatment options. I think the main difference is that with phototherapy, we don't expect the same speed of improvement that we're going to certainly see with traditional immunosuppressants, like cyclosporine. Biologics are really getting close to that rapid speed of onset, but phototherapy is slower and takes longer to have its clinical benefit. We need to set that expectation. 

The first thing I would probably do is just say that phototherapy has great safety and a long history in dermatology. If you want the treatment to get clear skin really quickly, this is not the go-to option. If you're really sensitive to light, we want to try to control for that. Certainly, we need to think about things like dyschromia or lack of efficacy with darker pigmentation. I like to set that up as this is one of many treatment options. I often will tell patients that I don't really care which direction they go or what they choose, I just want to make sure that they understand what they're getting. That's going to save us those unnecessary phone calls from patients saying, "I'm several weeks into my treatment, and I'm not really seeing much improvement." That's going to be a very different discussion now because of our setup.

Overall, I mostly just tell patients that phototherapy is quite effective and that we're not really worried about much in regard to safety. We're going to follow established protocols and algorithms that are going to help you slowly wean into this treatment. That's really the way I set it up. The biggest drawback, I think, for some patients can be the copays with each visit. That's often limits it. Additionally, in some situations, it's just not convenient. COVID-19 was a good example, when sending people to medical offices was the clear downside. For the most part, we can apply phototherapy pretty easily to many patients in many different scenarios, which makes it a really robust treatment option. 

Bhutani: I totally agree. As Mona mentioned, phototherapy, to me, is still one of the safest treatments that we have for psoriasis. When I counsel patients, at least in my neck of the woods, many of my patients want "natural" treatments. I always say that I don't think you can get any more natural than UVB light. 

I also tell them that because we're taking out these specific wavelengths, like Mona mentioned, we don't have any convincing evidence to show us that there might be an increased risk for skin cancer or anything that we might see from natural sunlight. Those are two ways that I appease my patients. 

At the same time, like you said, it is a big time commitment, right? They have to come into the office two to three times a week to start. We're talking about 3-6 months to see clearance of their disease. You really want to make sure that they're ready to make that leap and make that commitment. 

Mona, is there anything else that you talk to your patients about? 

Shahriari: I do talk to them, actually, about very similar concepts that you guys discussed: some redness, itching, blistering, or burning. As you mentioned, this is safer than natural sunlight, so I do try to emphasize that with patients. I do get the question of why can't they just use a tanning bed? Why do they have to come to the office to get the narrowband treatment?

I do reiterate with them that not only are tanning beds not effective for plaque psoriasis but also, they're using a completely different wavelength that could lead to skin cancer and melanoma. We, as dermatologists, don't recommend that for the use for psoriasis treatment. 

Bhutani: Absolutely. I think that's a great point: Our medical-grade phototherapy boxes are not the same as getting a tanning-bed treatment. 

Although, getting back to Jason's point, patients will get a suntan when they get phototherapy. For some patients, that's actually an added benefit. For some patients, they hate that. It is something that we want to, again, counsel patients when we're talking to them and setting expectations for them. 

Getting to access to phototherapy: We mentioned that during COVID-19, it was hard to get into an office. We also know that phototherapy centers just aren't available in a good part of our country, unfortunately. Most of them are centered on the coasts — the East Coast and West Coast — when we look at maps of phototherapy centers or around major urban hubs. 

How do you implement home phototherapy? How do you use that in your practice? Jason, do you want to get started? 

Hawkes: Phototherapy for the home gives people options. It's sometimes a bit of a dance to try to figure out coverage. Cost can be an issue, so you're always navigating that. I think working directly with the phototherapy unit manufacturers can certainly be helpful. 

Even where I am, in the outskirts of Sacramento area, there are many individuals in rural areas that don't want to come into the cities. They have ranches, or they're busy. Home phototherapy gives that extra layer of convenience where, again, you're removing the travel and treatment copayments. You're also removing the doctor's visits, and that gets back more to the “natural” side of treatment for some patients. 

Less interaction with the healthcare system, for some patients, is preferable. I think, particularly, hands and feet can be really good body sites for home phototherapy treatment because they're harder areas to treat due to the thickness of the acral skin. You have to select the right patient though. 

There are some patients where unsupervised treatment, like home phototherapy, is not an ideal situation. I'm a little more cautious in the selection of patients to whom I would say, "Let's just get you this treatment option at home" because you lose the protective guardrails. It makes me a little nervous with certain patients. It’s about proper patient selection. 

The reason we have many available therapies is that injections or biologics aren't great for everybody. Pills aren't great for everybody either. We're trying to personalize that treatment approach, and removing tailored treatment plans is very problematic. 

I also find that the community physicians, who may be a little closer to patients than many academic centers, are great phototherapy advocates. One thing we know about phototherapy is that it's very good from a business standpoint. It works in the background of usual patient care. It can help some of these smaller practices survive financially. It also keeps us off the radar from some of the big insurance companies that are watching for providers with high biologic utility. We know that it is a balance. I think this treatment diversity is good for everybody. And patients can choose their own treatment adventure if you want it to look a certain way. 

Bhutani: Agreed. My favorite way to utilize home phototherapy, although it's not always possible, is for them to do phototherapy with us in office, even if it's just for a month or 2. Then, they can learn a little bit of that art, how to do the dosing, what to expect, when to decrease the dose, and when to increase the dose. 

Again, that's not always possible. I also like that because then we know whether it is working before we make the investment into trying to get them a home phototherapy box. That's how I utilize it in my practice. I'm curious to know about the accessibility where you practice. 

For me, here in San Francisco, our Medicare patients, sometimes Medi-Cal/Medicaid patients, have really tough access to systemic therapies. Phototherapy is actually really well covered under these plans. Is that what you are seeing where you're practicing as well? 

Shahriari: In the northeast, we have a very similar issue. If patients have commercial insurance, it's very easy to get some of the systemics because of the access programs that various companies have. For Medicare and even Medicaid sometimes, it is a challenge. 

The problem we have in the northeast, which you have in the Bay Area as well, is that we don't have a lot of square footage in everybody's houses, depending on where they're living. Sometimes, the home light units aren't going to be ideal for patients if they're living in a high-rise in Manhattan, for example. We do have to tackle that aspect of things as well. I know for the longest time, I used to think that home light units weren't necessarily as efficacious as what we do in the office. 

There was that recent study that Joel Gelfand and colleagues put out that really showed that the home light units, when you teach the individuals appropriately, can actually be noninferior to what we use in our offices. For me, at least, that made a difference in terms of my prescribing habits for home light units. 

Bhutani: Totally agreed. Again, getting back to Jason's point about patient selection, if we can pick the right patient whom we know is going to be optimizing their dosing and be safe at home, then I think that home phototherapy can be just as effective as in-office phototherapy. 

Lastly, I think one of my favorite things that I have picked up doing phototherapy for a long time is social connection. I think there are patients who actually benefit from coming into the office three times a week and getting to know our nurses and having that handholding, especially some of my older patients who might be living alone or don't have family in the Bay Area. 

They truly become family in our phototherapy center. In the back of my head, I oftentimes do think about this for patients who might be really anxious or might need a little bit more handholding and a little bit more love in their therapeutic treatment. 

That's another time that I choose phototherapy because I think they really feel well taken care of when we're seeing them so many times a week and getting to know them. 

Hawkes: Tina, I was just thinking while you were talking: One interesting aspect that we need to consider as practitioners is that, obviously, we're hearing often about the systemic effects of untreated psoriasis and the inflammation. I always mention to my patients that we really don't have a good understanding of how effective phototherapy is in terms of potentially altering or modifying that risk with some of these comorbidities. It's an important research gap. 

We don't have the answers, but it's at least the other side of the coin to think about. As we consider this systemic inflammation in our patients, that might be a drawback of phototherapy for a patient with psoriasis who is at high risk for cardiovascular disease, obesity, diabetes, or some of the other psoriasis-associated comorbidities. Again, we're getting back to that proper patient selection. 

We want to understand how phototherapy might alter systemic inflammation. We're still learning whether we can still have those beneficial systemic effects with phototherapy, but probably not as much as other systemic agents. Again, maybe for those patients who have that higher burden of disease and inflammation, phototherapy may not be ideal as a monotherapy. This is something that we should be thinking about as practitioners. 

Bhutani: I think that's a great point. Again, I think that's an area where we still need to learn. We don't really understand exactly all the intricacies of how phototherapy actually works, right? What is the complete mechanism? 

Another shoutout to Joel Gelfand. We have two shoutouts to him in this talk. In one of his studies, when he looked at systemic inflammation in patients getting a multitude of different therapies — he did have phototherapy as an arm in one of those studies — and they showed a slight decrease in systemic inflammation. 

Again, I agree with you. Phototherapy probably does not have as large of an effect as some of our systemic therapies. I think we still are probably making an impact on inflammation, just by keeping the skin under check, right? Keeping that skin inflammation under control. 

Shahriari: I think the best take-home message is that we have to treat the whole patient and not just the skin. I know, for example, in my patients who are pregnant or who have a multitude of comorbidities and maybe can't take a pill or an injection is not going to be feasible, it's a great option. 

For the majority of patients, patient selection — really, Jason, you hit the nail on the head there — is going to be an important part. What I like about phototherapy is that you don't have to use it on its own. You can combine it. If someone's on an injection or if they're on an oral, maybe this gives them a little boost in efficacy. We have that ability to safely combine it with other therapies as needed. 

Bhutani: Getting back to your point, Mona, about special populations: I love to use phototherapy in pregnant women and pediatrics. Some people think that they don't want to put kiddos in a light box, but it's totally safe to do so as long as they're old enough to follow the instructions or can stand in there alone. 

I also love it in patients with many other comorbidities. Like you said, people who might not be able to take systemic therapies. Maybe they have active cancer, HIV, or active hepatitis B. These are other scenarios where I really love to use phototherapy. 

Let's talk a little bit about treating patients with skin of color with phototherapy. Mona, are there any special considerations that you think about when you're treating this patient population?

Shahriari: I know Jason alluded to this earlier, but melanin acts as a UV filter. The reality is that when we were doing our studies on phototherapy and trying to figure out optimal dose and duration of exposure, we really didn't study patients with skin types V and VI. It was just types I-IV. We don't really know what those optimal doses are to get the right result. 

In addition to that, for some cultures, being fair is valued, and being tan is stigmatized. They may not be in favor of going into a light box, with tanning being the adverse event that they have to deal with. It really does come down to a case-by-case discussion. Like we mentioned before, patient selection is going to be very important. 

Bhutani: I totally agree. I think we also have to remember that Fitzpatrick skin type or skin color doesn't always match up with someone's sun tolerance. I have had many patients with type VI skin, but they actually can't handle much UV light. 

I think we also have to be careful. You want to be aggressive enough so that we're not undertreating our patients with skin of color, but we also want to be cautious because they can still be sun sensitive.

Hawkes: To your point, Tina, it even changes over time, right? Individuals who say, "When I was a teenager and in early adulthood, I never burned and always tanned." All of a sudden, now, they never tan and always burn. They can have a UV response at one point in time, and over time, develop a different response. I think that's always important when restarting a patient on phototherapy who had treatment a long time ago to restart treatment a little bit slower to see how their initial response. 

Bhutani: I totally agree with that. It's important to treat the whole patient. I would like to thank Dr Shahriari and Dr Hawkes for joining me today. Thank you all for listening. We hope that you'll be able to utilize phototherapy in your practice. Thank you.