For decades, people with psoriasis have been treated in clinics with narrowband ultraviolet B phototherapy, or light therapy, to reduce sores, scales, and inflammation. Now, new research from the Perelman School of Medicine at the University of Pennsylvania shows that patients can improve their psoriasis just as well at home with phototherapy devices designed to make treatment easy to self-administer.

Phototherapy is provided by machines that resemble tanning beds or that can be smaller devices for hands or feet, but they emit a specific wavelength of ultraviolet light that treats psoriasis effectively without exposing patients to the cancer-causing wavelengths that are found in commercial tanning beds. Phototherapy is often used in combination with pills and biologic therapies for psoriasis (12% of patients were taking these medications during the LITE study).