Is acute idiopathic pericarditis associated with recent upper respiratory tract infection or gastroenteritis? A case-control study.

Objectives: The aim of this study was to assess the association of a clinical diagnosis of acute idiopathic pericarditis (AIP), and a reported upper respiratory tract infection (URTI) or gastroenteritis (GE) in the preceding month. Design: Patients who were hospitalised with a first diagnosis of AIP were retrospectively compared with a control group of patients admitted with deep vein thrombosis (DVT), matched by gender and age. Setting: Primary and secondary care level; one hospital serving a population of about 170 000. Participants: A total of 51 patients with AIP were included, of whom 46 could be matched with 46 patients with control DVT. Only patients with a complete review of systems on the admission note were included in the study. Main outcome measure: Conditional logistic regression was used to assess the association of a clinical diagnosis of AIP and an infectious episode (URTI or GE) in the month preceding AIP diagnosis. Results: Patients with AIP had more often experienced a recent episode of URTI or GE than patients with DVT (39.1% vs 10.9%, p=0.002). The multivariate conditional regression showed that AIP was independently associated with URTI or GE in the last month preceding diagnosis (OR=37.18, 95% CI=1.91 to 724.98, p=0.017). Conclusions: This is, to the best of our knowledge, the first study demonstrating an association between a recent episode of URTI or GE and a clinical diagnosis of AIP.