Venous thrombotic events in psoriasis patients: a systematic review with meta-analysis

BACKGROUND: Psoriasis is a chronic inflammatory skin disease associated with numerous comorbidities. Psoriasis has been linked to an increased risk of metabolic syndrome and atherosclerotic arterial disease. Inflammatory conditions are known to increase the risk of venous thromboembolism (VTE), a frequent cause of morbidity and mortality. However, the relationship between psoriasis and VTE has received little attention and existing studies have shown conflicting results. OBJECTIVES: This systematic review aims to perform a meta-analysis on VTE in psoriasis patients. METHODS: We conducted a systematic electronic search of the incidence of VTE (pulmonary embolism [PE], deep venous thrombosis [DVT] and/or retinal vein occlusion [RVO]) in psoriasis patients on PubMed, Web of Science, Embase and Cochrane (specifics: see Appendix 1 in Supporting information). Only English literature and full manuscripts were included; abstracts were excluded. Pooled risk ratio and 95% confidence interval were calculated using Review Manager. RESULTS: Seven articles were included. Each study separately indicated a correlation between psoriasis and VTE after adjustment for several clinical parameters. The confounders included in the adjustment differed between studies, but all included adjustment for age, gender and comorbidities. A meta-analysis of the unadjusted data of the five studies that reported raw data on number of VTE events and patient follow-up (person-years) showed a pooled risk ratio for VTE and psoriasis of 1.29 (95% CI: 0.92–1.81). The statistical heterogeneity was high with I(2) of 97%. CONCLUSIONS: Published data adjusted for key confounders demonstrate in general a significantly increased prevalence of VTE in psoriasis patients. Both psoriasis severity and number of confounders assessed seem to have an impact on this correlation. In this review, we pooled unadjusted data of the studies and we found a non-significant increased risk for VTE in psoriasis patients compared to healthy controls. This discrepancy suggests that psoriasis severity, age, gender or comorbidities may influence the risk of VTE in subgroups of the psoriasis population. Future research to identify subgroups at risk for VTE is warranted. KEY MESSAGES: The included studies reported an increased risk of VTE, DVT, PE and RVO in psoriasis patients. A meta-analysis was performed on five studies that reported raw data and showed that the pooled risk ratio for VTE in psoriasis patients overall was increased, however not significantly, compared to healthy controls. Further research to pinpoint psoriasis subgroups at risk (e.g. severe psoriasis patients, younger age, associated comorbidities) of developing VTE is warranted.