Smoking and Nail Psoriasis: Examining the Connection in a Case-Control Study Publisher



Shakoei S ; Heidari F ; Nasimi M ; Hamzelou S ; Saberi F ; Babaie H
Source: Dermatologic Therapy Published:2026

Abstract

Background: Nail psoriasis (NP) significantly affects patients’ quality of life and is associated with psoriasis severity. Smoking is a preventable risk factor that has been tied to poor disease outcomes, but its effect on NP is not well established. The purpose of this work is to analyze the connection between smoking and NP severity and occurrence. Methods: For this case-control study, 218 psoriasis patients and 218 controls were enrolled. The smoking history was collected, including the time and number of cigarettes smoked per day. The Nail Psoriasis Severity Index (NAPSI) was used to assess the severity of NP. In contrast, the Psoriasis Area and Severity Index (PASI) was used to evaluate the overall severity of psoriasis. Results: The results of the study showed that the prevalence of smoking was higher among the patients with psoriasis (27.5%) as compared to controls (6.0%; p < 0.001). Among the psoriasis group, current smokers had more severe NP than nonsmokers (23.8 ± 18.6 vs. 12.3 ± 11.2, p = 0.001) as assessed by NAPSI. PASI and the incidence of psoriatic arthritis were not significantly influenced by smoking. Conclusion: In conclusion, our results suggest that smoking is significantly associated with increased severity of NP. These results highlight the importance of incorporating smoking cessation in psoriasis patients’ care. Our study adds to the body of literature that highlights the importance of lifestyle changes such as smoking cessation for the improvement of NP. Prospective studies are required to investigate the impact of smoking cessation on the development and severity of NP. Copyright © 2026 Safoura Shakoei et al. Dermatologic Therapy published by John Wiley & Sons Ltd.