By Maria Cohut

Fact checked by Paula Field

New research has found evidence suggesting that a person’s body mass index can increase their risk of developing psoriasis, an increasingly common skin condition. The mechanisms at play, however, remain unclear.

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDKD) estimate that 32.5% of adults in the United States are overweight and 37.7% have received a diagnosis of obesity.

The NIDDKD also define being overweight as having a body mass index (BMI) of 25–29.9 and having obesity as having a BMI of at least 30.

At the same time, reports indicate that psoriasis, which is a common, chronic skin condition, affects about 2% of the U.S. population.

Studies have shown that over the past few years both obesity and psoriasis have been on the rise in the U.S. Some investigations have also revealed a correlation between the presence of psoriasis and that that of obesity. Could there be a causal relationship between these two conditions?

Now, researchers from collaborating institutions worldwide, including the University of Bristol in the United Kingdom, and the K.G. Jebsen Center for Genetic Epidemiology in Trondheim, Norway, has investigated precisely this possibility.

According to Dr. Mari Løset, one of the investigators who contributed to this study, “[h]igher BMI may contribute to increased inflammation of the skin, which can exacerbate psoriasis, but it could also be that psoriasis leads to a person being less physically active and thus gaining weight.”