Cigarette smoking, alcohol use, and obesity among patients with prurigo nodularis in the UK

Prurigo nodularis (PN) is a chronic, inflammatory skin disorder characterized by chronic itch and pruritic nodules. The role of modifiable lifestyle risk factors in PN, including cigarette smoking, alcohol use, and obesity, remains unknown. We performed a cross-sectional analysis of a retrospective, matched cohort from The Health Improvement Network (THIN®). PN patients were matched 1:1 to controls, based on age, sex, and race/ethnicity. We primarily compared rates of cigarette smoking, alcohol use ( 1 drink/day), and obesity between PN patients and controls. We also performed multivariable logistic regression adjusted for sociodemographic characteristics to determine whether PN was associated with increased frequency of these lifestyle risk factors. There were 6,090 patients in the PN and control groups and the majority of patients were female (58.4%) and White (86.5%) with a mean age of 56.7 years. PN patients were significantly more likely to smoke cigarettes (22.7% vs. 18.6%; P <0.001) and be obese (35.0% vs. 25.2%; P <0.001) in comparison to controls. There was no difference in alcohol use between the two groups. Similarly, PN was associated with increased risk of cigarette smoking (adjusted odds ratio [aOR]: 1.30; 95% CI 1.18-1.42) and obesity (aOR: 1.62; 95% CI: 1.48-1.77) in multivariable logistic regression models. PN was associated with significantly increased rates of cigarette smoking and obesity. Further research is necessary to determine if these lifestyle risk factors are associated with the development and progression of PN. Physicians may consider screening and counseling for these factors to improve outcomes.