Smoking is an independent risk factor for psoriasis, with particularly strong associations for heavy smokers and those who have smoked for many years, according to research published in the March 1 issue of the American Journal of Epidemiology.
To determine whether there was an association between psoriasis and smoking, Wenqing Li, Ph.D., of Harvard Medical School in Boston, and colleagues looked at data for 2,410 adults with incident psoriasis who were identified among 185,836 participants from three study cohorts.
The researchers found that past and current smokers had an increased relative risk (RR) of incident psoriasis compared with never smokers (1.39 and 1.94, respectively). For current smokers, there was an increasing risk for more cigarettes smoked per day (RRs for one to 14, 15 to 24, and 25 or more cigarettes/day: 1.81, 2.04, and 2.29, respectively).
