Phototherapy treats skin conditions
Dr. Mac Jones stands next to the phototherapy box at his clinic.
Dermatologists are turning to an enhanced form of phototherapy to treat a number of skin diseases, from psoriasis to certain types of skin cancer.
The therapy uses a narrow band of UVB rays that concentrates treatment on the epidermis or top layers of the skin.
"Narrowband UVB emits a safe light therapy and is more effective for a wide range of skin diseases as well as pruritic or itchy disorders," said Dr. Mac Jones, a board-certified dermatologist at the Dermatology Clinic of Jackson. "Our clinic has the only phototherapy box for narrowband in Jackson."
The treatment is effective on …
- Moderate to severe psoriasis, a condition where the skin cells replace themselves three times faster than normal, causing the skin cells to pile up and create red scaly plaques on the skin.
- Atopic dermatitis, often called eczema, which causes itchy, red patches on the skin.
- Vitiligo, a condition where people lose pigment in their skin, causing complete loss of pigment or depigmentation.
- Early mycosis fungoides, a rare type of lymphoma (cancer) that affects the skin.
- Pruritic disorders, abnormally itchy skin, can occur, for example, when someone is on dialysis or from other causes.
The UVB narrowband rays decrease cell proliferation, cause immunosuppression and kill cancer-causing T-cells.
In the past, UVB phototherapy used a broadband wavelength, a spectrum from 280 to 320 nanometers. "Narrowband" refers to a specific wavelength of ultraviolet (UV) radiation, 311 to 312 nm. "We’re now able to focus on the narrowband UVB spectrum," Dr. Jones said. This is less than 1 percent of total range of wavelengths from sunlight.
The UVB narrowband wavelengths are not to be confused with the UVA wavelengths that are used in tanning beds. "UVA is a completely different wavelength," Dr. Jones said. "It penetrates deeper into the skin and damages the collagen and elastic fibers in the dermis."
Narrowband light therapy is better than broadband for several reasons …
- Exposure times are shorter but more intense.
- The course of treatment is shorter.
- It is more likely to clear the skin condition.
- Longer periods of remission occur before it reappears.
Dr. Jones recommends that patients come in for narrowband UVB therapy two to five times a week. The patient puts on protective eye goggles, removes clothing except for undergarments and steps into a cylinder lined with fluorescent light bulbs. This is performed in a special, private room.
The light therapy itself can range from a few seconds to several minutes. "Treatment length, which differs with each patient, his or her skin type, age, skin condition and other factors, is gradually increased until the patient reaches an optimal exposure time," Dr. Jones said.
The amount of UVB is carefully monitored, he said. The goal is to give enough therapy until the patient’s skin is slightly pink when therapy is over. It’s called the MED, Minimal Erythema Dose.
"Treatment is continued until complete remission of the disease is achieved, or we reach the endpoint where no more improvement is occurring."
One of the advantages of narrow band therapy, Dr. Jones said, is that it is 10 times less likely to make your skin turn red. He listed other advantages …
- It can be used in conjunction with other therapies for psoriasis, such as oral medications, biologicals and topicals with only a few exceptions.
- It is covered by most insurance policies.
"Narrowband UVB therapy works very well,” he said. “Patients are absolutely happy with it."