Women susceptible to the skin syndrome psoriasis may want to put down the stout and reach for a light beer. A new study finds that drinking regular beer increases the risk of psoriasis in women by over 70 per cent.

Psoriasis is an auto-immune disease that causes scaly lesions, redness and inflammation of the skin. According to the National Psoriasis Foundation, 2.5 per cent of Caucasians and 1.3 per cent of African-Americans have the disease. Doctors aren’t sure of the exact cause of psoriasis but believe that something triggers the immune system, setting off a chain reaction that causes skin cells to reproduce too quickly.

To evaluate the association between different types of alcohol and psoriasis risk, Dr. Abrar A. Qureshi of Brigham and Women’s Hospital and Harvard Medical School assessed years of follow-up data from 82,869 women participating in a 1991 study.

The women, who were 27 to 44 years old at the study outset, were participants in the Nurses’ Health Study II, which asked multiple questions of them every two years. The questions included the amount and type of alcohol they consumed, and whether they had received a diagnosis of psoriasis.

Through 2005, the women had reported 1,150 diagnoses. Researchers used 1,069 of them for analysis and determined that women who reported averaging at least 2.3 drinks per week had a 72 per cent greater risk of psoriasis than women who did not drink. However, they also found no association between psoriasis risk and light beer, red wine, white wine or liquor.

They found that drinking five or more non-light beers per week raised psoriasis risk 1.8 times higher than that of women who drank no beer. And when considering only confirmed psoriasis cases – those in which women provided more details about their condition, in a seven-item self-assessment- researchers found the risk for psoriasis was 2.3 times higher.

Barley and other starches contain gluten, to which some individuals with psoriasis show sensitivity. Light beer contains less grain than regular beer, the scientists noted.

“Women with a high risk of psoriasis may consider avoiding higher intake of non-light beer,” the researchers write online today in the journal Archives of Dermatolog. “We suggest conducting further investigations into the potential mechanisms of non-light beer inducing new-onset psoriasis.”

Certain alcoholic beverages have been shown to influence risk of other diseases, too – for instance, beer confers a larger risk for gout than spirits or wine do (although beer may also be good for your bones).