What Is Psoriasis?
Psoriasis is an autoimmune disease that affects over 8 million people in the U.S. and 2–3% of people worldwide. It occurs when a person’s immune system sends “faulty signals” and causes skin cells to grow too rapidly. As a result, skin cells accumulate on the skin surface, forming bumpy red patches covered with white scales, known as psoriasis lesions.
People who have psoriasis can have skin flare-ups—and they can surface anywhere on the body, including the scalp, eyelids, elbows, or knees. According to the National Psoriasis Foundation, the disease is believed to be caused by a combination of genetics and external factors.
Moreover, people who have psoriasis also have an increased risk of developing other health conditions, including psoriatic arthritis (a form of arthritis that affects some people with psoriasis), diabetes, and depression.
Psoriasis is not contagious. It typically appears in early adulthood, and for most people, it affects only a few areas. In extreme cases, psoriasis can cover large parts of the body. The plaques can heal and then come back throughout a person’s life.
What Is Light Therapy (Phototherapy)?
Light therapy is a safe alternative to traditional prescription creams and injections that can be done either with or without a dermatologist’s referral. Phototherapy for psoriasis involves a series of in-office treatments that are completed by exposing the skin to narrow-band UVB light. The key to success with light therapy is consistency.
Effective phototherapy treatment for skin conditions requires multiple sessions. Some patients can clear psoriasis completely with phototherapy alone. Others require combination treatments with medication. Phototherapy can be used safely with both biologics and topicals.
When ultraviolet light hits the skin, it inactivates the overactive immune cells in the skin that contribute to psoriasis. Research suggests that UV light may also disrupt the erroneous signals between immune cells and skin cells that lead to psoriasis lesions. With relatively few side effects, phototherapy is a safe, effective, and drug-free treatment for psoriasis.
According to a 2013 study in the American Journal of Clinical Dermatology, between 60%-75% of patients who received some type of light therapy achieved at least a 75% improvement in their condition.