Cigarette smoking is associated with the clinical severity of the skin disease psoriasis, and both smoking and obesity are more prevalent among psoriasis patients.
Psoriasis is a chronic, persistent, lifelong disease characterized by scaly red plaques on the surface of the skin. Although psoriasis is not a life-threatening disease, the disability experienced by patients with psoriasis is comparable with that of patients with other chronic illnesses, such as heart disease, diabetes, cancer, and depression, according to background information in the article. Cigarette smoking is a risk factor for many chronic diseases, including psoriasis, but little is known about the effect of smoking on psoriasis severity.
Cristina Fortes, of Istituto Dermopatico dell'Immacolata, Rome, Italy, and colleagues conducted a cross-sectional study to evaluate the association between different components of smoking history and the clinical severity of psoriasis. They analyzed data on 818 adults with psoriasis in inpatient wards of a hospital for skin diseases.
The study is published in the Archives of Dermatology.
" Specifically, patients who smoked more than a pack of cigarettes ( more than 20 cigarettes ) daily had twice the risk of more severe psoriasis compared with those who smoked ten cigarettes or less per day," the authors report.
Cigarette-years, measured as the product of the intensity and duration of smoking, significantly increased the risk of clinically more severe psoriasis. " Separate analyses for men and women showed that the effect of cigarette-years on psoriasis severity was stronger for women than for men, " the authors write.
" Smoking is associated with the clinical severity of psoriasis and highlights the importance of smoking cessation in patients with psoriasis," they conclude.
In another article, published in Archives in Dermatology, researchers report that the prevalence of both smoking and obesity is higher among patients with psoriasis than in the general population.
Mark D. Herron, and colleagues from the University of Utah School of Medicine, Salt Lake City, studied the impact of obesity and smoking on psoriasis. A case series of patients with psoriasis enrolled in the prospective Utah Psoriasis Initiative ( UPI ) was compared with three population databases: the Behavioral Risk Factor Surveillance System of the Utah population, the 1998 patient-member survey from the National Psoriasis Foundation, and 500 adult patients who attend the University of Utah Department of Dermatology clinics and do not have psoriasis.
" The prevalence of obesity in patients within the UPI population was higher than that in the general Utah population ( 34 percent vs. 18 percent ) and higher than that in the non-psoriatic population attending our clinics," the authors write. " The prevalence of smoking in the UPI population was higher than in the general Utah population ( 37 percent vs. 13 percent ) and higher than in the non-psoriatic population."
The authors found that obesity appears to be the consequence of psoriasis, and not a risk factor for onset of the disease. " Smoking appears to have a role in the onset of psoriasis, but obesity does not," they write.
" It seems certain that the cost of providing care for psoriasis when coupled with the increased frequency of obesity and smoking in patients attending clinics such as ours will continue to increase," the authors conclude. " An effort to control obesity and smoking in psoriasis patients and an increased appreciation of the effects of these comorbidities are clearly needed."
Source: American Medical Association, 2005