The association between psoriasis and chronic obstructive pulmonary disease: a systematic review and meta-analysis.

Introduction: Psoriasis is a chronic T-cell-mediated inflammatory and proliferative skin disease. Chronic obstructive pulmonary disease (COPD) is an inflammatory disease of the airways. COPD has been studied as a comorbidity of psoriasis, but the association needs further study, hence the objective of this study.

Evidence acquisition: A systematic review was performed using the database PubMed and 155 records were found including the ones found through references. Seven records were found eligible for this study including six observational studies and one experimental study with a total of 229,075 participants. The odds ratio of COPD in patients with psoriasis and healthy subjects was analysed using a random effects model.

Evidence synthesis: The pooled data showed a significant association (OR=1.77, 95% CI [1.32; 2.39]) between psoriasis and COPD with high inter-study heterogeneity (I²=96%). Sub-analyses of the different types of studies (cohort study: OR=2.53 [2.43; 2.63], case-control study: OR=1.6 [0.03; 100.96] and cross-sectional study: OR=1.57 [0.58; 4.22]) and smoking status (OR=1.7 [0.69; 4.14]) were also performed to further examine the association.

Conclusions: There is a significant association between psoriasis and COPD, but the underlying mechanism and how smoking status affects the results remain unclear and need further study. Physicians should be aware of the risk and its seriousness to provide better and more targeted treatment.