At the end of the 20th century, the World Health Organization found that the related factors affecting people's health were: medical conditions accounted for 8%, biological genetic factors accounted for 15%, environmental factors accounted for 17%, and lifestyle and behavior accounted for 60%.

        Psoriasis is a typical psychosomatic skin disease. Bad behavior and lifestyle is an important factor leading to the occurrence and recurrence of psoriasis. Smoking is a risk factor for psoriasis. Long-term clinical observation has confirmed that smoking can aggravate psoriasis.

        In fact, the association between smoking and psoriasis has been noted for a long time and was limited to case reports. In recent years, the correlation between smoking and psoriasis has been reported more and more. Zhang Xuejun et al. found that the number of smokers in male patients with psoriasis was significantly higher than that in the normal control group, and the number of smokers in psoriasis patients was significantly correlated with the severity of the disease. The greater the amount of smoking, the more severe the disease was. Data from the United States, Italy, Finland, Norway and other countries also show that the proportion of smokers in patients with psoriasis is higher than the normal population. Data of psoriasis in Utah showed that 37% of the more than 800 patients with psoriasis were smokers, and 13% of the general population were smokers. 78% of the patients with psoriasis smoked before the onset of the disease, and 22% started smoking after the onset of the disease. Data from Italy and other countries clearly identify smoking as a risk factor for psoriasis. Naldi et al. confirmed that smoking about 15 cigarettes a day is a risk factor for psoriasis, especially in women. A detailed report published in The American Journal of Medicine in November 2007 was The first to analyze The relationship between smoking status, duration, intensity and risk of psoriasis. Studies have shown that smoking can stimulate the release of oxidase after neutrophil activation, enhance the chemotaxis and adhesion of neutrophils, promote inflammation, and aggravate psoriasis. Keratinocytes have nicotinic cholinergic receptors, which can stimulate calcium influx and accelerate cell differentiation. Long-term stimulation of these receptors can inhibit the adhesion and terminal differentiation of keratinocytes. Both oxides in smoke and reactive oxygen species from the activation of phagocytes can lead to tissue oxidative damage.