That’s because the skin condition, as it turns out, is particularly responsive to a frequency of ultraviolet light known as narrow band or low-energy light therapy. At this point, narrow band therapy has supplanted older, broader band treatment options for psoriasis. According to a paper from May 2017 by the Institute for Quality and Efficiency in Health Care, light therapy for psoriasis can lead to partial or complete symptom improvement for 50 to 90 percent of people who use it. Phototherapy may help with psoriatic arthritis, as well. Treating PsA, however, typically involves using a number of different therapies rather than a single treatment. “You do get a systemic modulation of the immune system [from phototherapy]. It’s interesting that when you treat the skin, the joints respond,” says Jami Miller, MD, an associate professor of dermatology and supervisor of the phototherapy clinic at Vanderbilt University Medical Center in Nashville, Tennessee. But just how much the joints respond is in question. “Psoriatic arthritis needs to be controlled by drugs — it can be very destructive if it’s not treated aggressively,” says Yusuf Yazici, MD, a rheumatologist and clinical associate professor of medicine at NYU Grossman School of Medicine in New York City.
Types of UV Light Treatment for Psoriasis and Psoriatic Arthritis
Your doctor may suggest one or more of the following UV phototherapy or combination therapy approaches for psoriasis:
Ultraviolet B (UVB) UVB phototherapy is the gold standard light therapy, notes the Arthritis Foundation. The whole body (except for your eyes and genitals) is exposed to a large light box or a light source for a few seconds and up to a few minutes. This is typically performed three times a week over three months.Excimer Laser A more targeted UVB approach, this FDA-approved, hand-held device emits a high-intensity beam of UVB light to penetrate deep into the skin to treat small areas of psoriasis, particularly on the scalp.UVB and Coal Tar Topically applied coal tar can make the skin more receptive to light, so some doctors combine UVB with the product for a more effective result, according to the Mayo Clinic. This is also known as the Goeckerman treatment.PUVA (Psoralen and UVA) UVA rays aren’t particularly helpful for treating psoriasis on their own, but they become more effective when used with psoralens, which are light-sensitizing agents that seem to boost the therapeutic effects of light on the immune system. Psoralens can be administered topically (in a cream), mixed with water in a bath, or taken orally, according to the National Psoriasis Foundation (NPF). PUVA is often used for more severe cases of psoriasis. “PUVA is spectacularly effective,” says Dr. Miller. Because PUVA can be so powerful, however, the treatment is rarely used in children. And adults who undergo the treatment must wear sunglasses outdoors for 24 hours afterward to protect their eyes against naturally occurring UVA in sunlight.
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What You Need to Watch Out For
If you’re thinking of trying light therapy, there are several things to consider:
Darker complexions may not respond as well. While phototherapy for psoriasis can be used regardless of a person’s complexion type, light-skinned people typically respond more quickly than those with darker skin, Miller says.You might increase your cancer risk. Narrow band UVB therapy is safer, cancer-wise, than PUVA, which carries some risk of skin cancer, according to the NPF. If you are doing phototherapy, it’s important to get your skin examined by a dermatologist regularly. “The breaking point seems to be 250 sessions in a lifetime, so we try to limit it,” says Miller.Phototherapy is not recommended for people who have had melanoma. Or any other skin cancer, or for people who have a condition such as lupus that makes them sensitive to UV light, notes the American Academy of Dermatology.Patients controlling skin symptoms with a biologic drug should avoid light therapy. The Arthritis Foundation says that while most people are candidates for phototherapy, those maintaining excellent control of skin symptoms with biologics are an exception.There’s a major time commitment. The biggest deterrent for many patients is the hassle of traveling to a treatment site several times a week for months, Miller acknowledges.The therapy is not always easy to find — or pay for. As drug options have increased, phototherapy as a psoriasis treatment has experienced a decline in use, according to research published in November 2018 in the British Journal of Dermatology.Phototherapy can be expensive. According to a study published in June 2017 in the Journal of the American Academy of Dermatology, the average out-of-pocket cost for psoriasis phototherapy exceeds $2,500 annually. “Even if you have insurance, many plans require copays of up to $50 per visit,” says Lawrence Green, MD, a clinical professor of dermatology at the George Washington University School of Medicine in Washington, DC. Still, as a research review published in February 2021 in The Journal of the American Academy of Dermatology notes, phototherapy is less costly than biologics.
DIY or Don’t?
You may be able to treat your psoriatic arthritis with home UVB phototherapy, though people typically begin treatments at a medical facility, then go on to use a light unit at home, for both cost and affordability. A research review published in November 2019 in the journal Expert Review of Clinical Immunology notes that at-home phototherapy systems may improve treatment adherence and compliance in patients. For people who live in sunny climates, and have mild skin symptoms, getting 20 to 30 minutes of natural sunlight can also be an option, according to the Arthritis Foundation. Just be sure to use sunscreen to protect against burns. And it’s not a good idea to self-treat with tanning beds, notes the Arthritis Foundation. The devices tend to deliver too much UVA light, which can age your skin and raise the risk of skin cancer, so stay away. Additional reporting by Julie Marks.
