Relationship between Helicobacter pylori infection and psoriasis: a nationwide population-based longitudinal cohort study.

Background: In the current literature, studies assessing the role of Helicobacter pylori (HP) infection in psoriasis have reported conflicting data. Therefore, we investigated the association between HP infection and psoriasis using a nationwide population-based longitudinal cohort study. Methods: We identified 41,539 patients with HP infection and 83,078 matched controls between 2000 and 2013 from the Longitudinal Health Insurance Research Database of the National Health Insurance Research Database in Taiwan. Propensity score analysis was used to match age, sex, comorbidities, and medical visits at a ratio of 1:2. Multiple Cox regression analysis was used to estimate the adjusted hazard ratio of psoriasis. Furthermore, sensitivity tests and a stratified analysis were conducted. Results: The incidence rates of psoriasis did not differ significantly between the HP and control cohorts (4.58 vs 4.20 per 100,000 person-months, crude relative risk: 1.092, 95% confidence interval: 0.917-1.302). After multivariate adjustment, no significant difference in psoriasis risk was observed in patients with HP infection (adjusted hazard ratio: 1.081, 95% confidence interval: 0.907-1.288). Risk of psoriasis was significantly higher in men and the elderly, and in those with diabetes, hyperlipidemia, chronic obstructive pulmonary disease, or tuberculosis. Stratified analysis also confirmed that HP infection was not correlated with an increased risk of psoriasis based on follow-up duration, sex, and age. Conclusion: This retrospective population-based longitudinal cohort study, conducted in Taiwan, found no association between HP infection and risk of psoriasis. Further research may be warranted.