Smoking and psoriasis.

Many early studies examining the relationship between tobacco and the development of plaque-type psoriasis suggested a significant positive correlation; however, the majority of these initial studies failed to control for alcohol consumption and presented inconsistent results. The objective of this manuscript is to perform a literature review of articles assessing the relationship between smoking and psoriasis while controlling for confounders such as alcohol consumption. Alcohol-controlled studies suggest that women who are smokers have an up to 3.3-fold increased risk of developing plaque-type psoriasis. Men who are smokers do not exhibit such an increased risk, but studies have shown that smoking more than 10 cigarettes per day by men who are psoriasis patients may be associated with a more severe expression of disease in their extremities. In addition, smoking among both men and women who are psoriasis patients has been shown to reduce improvement rates. These data demonstrate the importance of discouraging smoking, particularly among psoriasis patients.