A litany of research has begun to shape the potential benefit of UV treatment for the skin disorder. Experts share what more needs to be known.
Vitiligo has been, since its very discovery, a complex dermatological disorder.
In fact, the word vitiligo, derived from the Latin vitulum or “small blemish”, has often been attributed to 16th century physician and medical practitioner Hieronymus Mercurialis.—who historians believe may have been referencing another skin disease such as leprosy at the time of his definition.
Fittingly, the 600-year history of addressing a disease borne from a complex identification is still without absolute methods of care. But in the year 2021, interest has piqued on ultraviolet (UV) therapy.
This past year alone, HCPLive has reported on nearly a dozen different investigations and hosted discussions on the efficacy of UV therapy for skin conditions such as vitiligo.
To gain a clearer perspective on UV therapy, HCPLive spoke with Raj Chovatiya, MD, PhD, Assistant Professor at the Department of Dermatology, Northwestern University Feinberg School of Medicine, as well as Yan Valle, Chief Executive Officer of the Vitiligo Research Foundation in New York.
Ultraviolet phototherapy can be divided into 2 groups: UVA and narrowband UVB light (nbUVB), both of which are named based on where they fall on the spectrum of light.
The practice of phototherapy has evolved over time, Chovatiya explained.
“Ultraviolet B light historically was broadband light between 280 and 320 nanometers, but the most common technologies you see for treatment today are narrowband UVB treatment which is between 311 and 313 nanometers,” he said. “This is the most effective part of the spectrum, and you can also see excimer lasers which are another delivery device for a higher amount of radiation of a shorter period concentrated at 380.”
When managing atopic conditions such as vitiligo, the function of UVB light is to suppress inflammation in the skin through a plethora of mechanisms, some of which haven't even been completely defined yet.
UVA uses longer wavelengths, at roughly 340 and 400 nanometers, but similarly reduces inflammation the skin. It is also capable of penetrating the skin deeper than UVB and can increase collagen breakdown.
“The biggest difference between UVB and UVA light is that there are some longer-term adverse risks associated with UV light, particularly photo-aging and photo carcinogenesis and sometimes skin cancer risks,” Chovatiya said. “So, there's caution with chronic use.”
Despite the risks associated with UVA light, UVB light is considered by some to be the first line treatment option.
“In practical terms, phototherapy remains the most effective therapy for vitiligo, with minor side-effects and high safety profile,” Valle said. “Signs of some re-pigmentation following phototherapy are observed in the majority of adult patients with non-segmental vitiligo, although complete re-pigmentation is only found in a minority (of patients).”
Though efficacious, the process of ultraviolet phototherapy requires patience and commitment by patients and clinicians.
On average, a patient will have to undergo 2-3 sessions of 180-200 nbUVB a week for 8-16 months to achieve noticeable re-pigmentation. However, not every patient responds to the therapy at a pace they’re comfortable with.
“About 25% of patients do not respond to phototherapy within the first 3 months, which is a deal-breaker point for phototherapy,” Valle said. “In my experience, most of (patients) could have responded in 4-6 months, but they’d be long gone by then.”
Valle added that Fitzpatrick skin types I and II are known to re-pigment weaker compared to types III and IV, regardless of the number of phototherapy sessions, and are prone to quick relapse.
“I think that there's definitely a balance you run between how well the therapy works and the amount of commitment it requires for the patient and the providing physician or other health care providers,” Chovatiya said.
While portable nbUVB devices are available and show comparable results to clinic-based therapy – (“at a fraction of headache and cost,” Valled added), complications regarding approval from a patient’s insurance provider can keep some patients from having access to home-based phototherapy options.
“I think that one of the biggest challenges with phototherapy, particularly narrowband UV, which is what we use the most, is finding a provider, and office, (or) a group that is very familiar with the technology so they know exactly how dosing works,” Chovatiya said.
He added that patients who are highly motivated and interested in the technology surrounding light-based therapy tend to find ways to work UV therapy into their weekly schedules, and that a better understanding of the administrative process of from a clinical perspective could result in more patients seeking out this type of therapy.
Regarding home therapy, Valle noted that it should always be supervised by an experienced doctor.
“We also need specialized education in residency and training thereafter to maintain the proficiency of physicians in a combination of tele-dermatology and home-based nbUVB treatments,” Valle said.
As is the case with most therapies in the dermatology field and beyond, UV therapy is most effective when paired with additional therapies and preventive measures.
“In the case of vitiligo, usually, we're not doing any one particular treatment approach at a time,” Chovatiya said. “Typically, in real world practice, it's combination treatments and approaches.
Chovatiya’s insights were reflected in several studies involving combination therapies reported by HCPLive this year.
In 1 study from Egypt, intralesional corticosteroid injections (ILS) combined with narrow-band ultraviolet B light therapy presented a well-tolerated therapeutic option for patients with vitiligo, with investigators from that study considering it to be “effective, simple, and relatively safe.”
Another study from Uzbekistan found that a combination of UVB rays of 311 nm and tab methotrexate decreased Dermatology Life Quality Index (DLQI) scores by 91.5%.
Chovatiya referenced several topical, anti-inflammatory options that have been combined with UVB treatment, including topical corticosteroids, topical calcium neural inhibitors, and even oral anti-inflammatory therapies in some instances.
Dermatologists will often continue using narrowband UVB when treating patients with topical therapies, with various trials and studies suggesting increased efficacy in combined treatment modalities.
Though not at the forefront of many doctor’s treatment strategies for atopic diseases such as vitiligo, a renewed interest in UV therapy has been cited by various medical professionals including Chovatiya.
“I think that phototherapy is one of those really effective and practical therapies that sometimes we don't necessarily think about, especially in the age of biologics, targeted topicals, topical, (and) targeted oral therapies,” Chovatiya said. “I think that there's a renewed interest now in figuring out how can we best optimize a technology that's been around that is very effective, that has a very favorable risk profile for patients, and combine it with some of these targeted treatment modalities to really take things to the next level.”
He added that over the next several years, the efficacy of UV-based phototherapy will be thoroughly documented in a variety of atopic diseases including atopic dermatitis, psoriasis, mycosis fungoides, and cutaneous lymphoma.
With documentation comes more data, and for UV-based phototherapy to be more closely associated with vitiligo treatment opportunities, more data needs to be made available. Six centuries into addressing this condition, definitions are as vital as ever.
“Getting more data back into specialty, particularly in terms of treatment, is great,” Chovatoya said. “The more data we can really get to actually say, ‘Yep, by looking at the numbers it matches the clinical experience, phototherapy is a really great option for our patients,’ is going to be what we really want to see.”