Published on April 06, 2022

Woman with skin condition.

Dermatologists use light therapy to effectively treat psoriasis

Psoriasis is a chronic autoimmune disease characterized by thick, red, scaly and often itchy patches of skin. It can cause considerable discomfort, not to mention self-consciousness, particularly when it appears on the head, neck or extremities.

According to the National Psoriasis Foundation, psoriasis affects more than 8 million Americans and 125 million people worldwide. Up to a third of patients experience psoriatic arthritis, which can cause significant joint pain and mobility issues.

Anyone can get psoriasis, but the condition is more common in adults. It is not contagious. It is caused by chronic inflammation in the skin leading to the characteristic plaques on the skin.

Diagnosis of psoriasis is made by a physician, typically a dermatologist. It’s best to seek treatment for psoriasis from a qualified medical professional.

"In mild cases, psoriasis can be treated with topical creams and ointments," said Kevin Ciriacks, MD, a dermatologist who practices with the ProHealth Medical Group. "Patients with more severe disease can also be treated with oral and injectable medications. Moderate to severe psoriasis that is difficult to control or is widespread often requires additional intervention."

Narrowband ultraviolet B (UVB) phototherapy, or light therapy, can help significantly improve psoriasis. Research has shown that light therapy can result in a 75% or greater improvement in psoriasis for many patients.

Performed in the dermatologist’s office, light therapy has the potential for fewer side effects than some other treatment options. Unlike some medications that affect the immune system, it can more safely be prescribed for patients who have an underlying medical condition that affects the immune system, who are pregnant, or who prefer to avoid the risks of other psoriasis medications.

The therapy is very safe. Because it exposes patients only to a narrow range of ultraviolet wavelengths, it is less likely to cause skin cancer than similar exposure to the sun’s natural UV rays or the lights in a tanning bed.

Initial light therapy dosage is determined based on an individual’s skin type and how easily the patient experiences sunburns or tans.

The therapy typically begins with short visits to a dermatologist’s office two or three times a week. For each treatment, patients typically step into a light box, where light bulbs emit a short burst of narrowband UVB light.

Treatment times range from a few seconds to a few minutes, depending on the patient’s skin type and number of prior light therapy sessions. The rays penetrate the skin, slowing the growth of affected skin cells and decreasing inflammation. UV blocking sunglasses are required during treatment.

A specially trained nurse or other health care professional provides assistance and is nearby during treatment.

Over the course of weeks to months, the skin often clears enough that the patient is satisfied with the results and can reduce the frequency of visits. Typically, light therapy visits continue two to four times a month for maintenance of desired treatment results. In some cases, dermatologists also recommend topical treatment as well.

Some people may try to treat psoriasis on their own in tanning beds. This is never a good idea. Unfortunately, using ultraviolet light without a physician’s supervision can pose significant health risks, including severe sunburn, photoaging and an increased risk for skin cancer.

In some cases, psoriasis patients may obtain a narrowband UVB light unit for use at home under a dermatologist’s care. If a patient decides to invest in a light box, the doctor’s office can help identify the best equipment options.

Dermatologists also work with insurance companies to help provide documentation needed for coverage of psoriasis treatment, based on each patient’s individual health insurance plan.