Alcohol intake and risk of incident psoriasis in US women: a prospective study.

Objectives: To evaluate the independent association between alcohol consumption and risk of developing psoriasis and to determine if this risk is associated with different types of alcoholic beverages.

Design: A prospective study of female nurses who were followed up from 1991 to 2005.

Setting: Nurses' Health Study II, a cohort of 116,671 US women aged 27 to 44 years in 1991.

Participants: The study population included 82,869 women who reported amount and type of alcohol intake on biennial questionnaires. We excluded participants with a history of psoriasis prior to 1991.

Main Outcome Measure: Self-report of incident physician-diagnosed psoriasis. For a sensitivity analysis, we had a subset of confirmed psoriasis cases.

Results: There were 1150 cases of incident psoriasis, 1069 of which were used for analysis. Compared with women who did not drink alcohol, the multivariate relative risk (RR) of psoriasis was 1.72 (95% confidence interval [CI], 1.15-2.57) for an alcohol consumption of 2.3 drinks/wk or more. When examined by type of alcoholic beverage, there was an association between psoriasis and nonlight beer intake (multivariate RR for ≥ 5 drinks/wk, 1.76; 95% CI, 1.15-2.69); light beer, red wine, white wine, and liquor were not significantly associated with psoriasis risk. The association with nonlight beer intake became stronger in a subset of confirmed psoriasis cases (multivariate RR for ≥ 5 drinks/wk, 2.29; 95% CI, 1.36-3.85).

Conclusions: Nonlight beer intake is associated with an increased risk of developing psoriasis among women. Other alcoholic beverages did not increase the risk of psoriasis in this study.