The objective of the study was to evaluate the relation between smoking and incidence of psoriasis in a women. The study found that women who smoked at  one time in the past and those women who were classified as “current smokers” were at increased risk for developing psoriasis. However, the risk was greater for those women who were currently smoking. The risk of developing psoriasis appeared to increase with the length of time they smoked and the number of cigarettes per day they smoked over that time period. Moreover, the risk of psoriasis decreased with each year of smoking cessation reaching nearly that of never smokers 20 years after quitting. (The issue here, however, is that the test subjects on average weren’t older than 60. Therefore, comparing ex-smokers who were 20 years post-quitting and age 60 vs. those that were never smokers and 35 might be a misleading comparison. )  Nevertheless, the study claims these associations were independent of other purported risk factors. The smoking-psoriasis study provides the first evidence that tobacco cigarette smoking is a strong risk factor for developing psoriasis.

Contradictory and/or important additional variables requiring further research:

- the relationship between obesity and incidents of psoriasis

- the fact that those that smoked at one time or classify themselves as current smokers consumer alcohol at 2x the daily rate as those who do never smoke. In other words, despite having quit smoking, ex-smokers continue to consume alcohol at 200% the never smoker category. To what extent is alcohol consumption/obesity a contributing factor?