This study involves the use of diet as a therapeutic agent in subjects with obesity and psoriasis who are eligible for and willing to undergo phototherapy. Subjects undergoing phototherapy alone will be compared to subjects randomized to receive phototherapy and dietary modification with the goal of weight loss. The primary objective is to determine the success rate of weight loss programs in the setting of psoriasis. Secondary objectives include evaluating the effect of weight loss on efficacy of narrow band ultraviolet B phototherapy, and assessing the efficacy of lower carbohydrate and low fat diets in psoriatic patients.
The association between psoriasis and obesity has been questioned by physicians for many years. Studies have shown that the risk of having psoriasis is increased in people with a high body mass index, which is a measurement of obesity. There have been case reports of remission of psoriasis after gastric bypass surgery. Furthermore, other studies have shown that certain inflammatory diseases (such as rheumatoid arthritis) can be improved by dietary changes. The purpose of this study is to assess whether a low carbohydrate or low fat diet can be helpful in the treatment of psoriasis.