Relationship between smoking and the clinical severity of psoriasis

Arch Dermatol. 2005 Dec;141(12):1580-4. doi: 10.1001/archderm.141.12.1580.


Objective: To evaluate the association between different components of smoking history and the clinical severity of psoriasis.

Design: A hospital-based cross-sectional study.

Setting: Inpatient wards of a hospital for skin diseases in Rome, Italy.

Patients: A total of 818 adults with psoriasis.

Main outcome measure: The Psoriasis Area and Severity Index was used to assess the clinical severity of psoriasis between February 21, 2000, and February 19, 2002.

Results: After adjustment for potential confounders (sex, age, body mass index, psychological distress, family history of psoriasis, duration of psoriasis disease, and alcohol consumption), high intensity of smoking (>20 cigarettes daily) vs a lower level of consumption (< or =10 cigarettes daily) was associated with a more than 2-fold increased risk of clinically more severe psoriasis (odds ratio [OR], 2.2; 95% confidence interval [CI], 1.2-4.1). Cigarette-years, measured as the product of the intensity and duration (years) of smoking, significantly increased the risk of clinically more severe psoriasis after adjustment for confounding factors (OR,1.3; 95% CI, 1.0-1.6, for a 600-U increase in cigarette-years). Separate analyses for men and women showed that the effect of cigarette-years was stronger for women (OR, 1.8; 95% CI, 1.2-2.6, for a 400-U increase in cigarette-years) than for men (OR, 1.2; 95% CI, 0.9-1.6, for a 700-U increase in cigarette-years).

Conclusion: Smoking is associated with the clinical severity of psoriasis and highlights the importance of smoking cessation in patients with psoriasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Cross-Sectional Studies
  • Female
  • Hospitals
  • Humans
  • Male
  • Middle Aged
  • Psoriasis / etiology*
  • Psoriasis / pathology
  • Psoriasis / prevention & control
  • Severity of Illness Index
  • Smoking / adverse effects*
  • Smoking Cessation
  • Surveys and Questionnaires