Acute pericarditis with pleuropulmonary involvement, fever and elevated C-reactive protein: A systemic autoinflammatory disease? A cohort study

•Aim of this study is to increase awareness in the scientific community for the earlier identification and differential diagnosis of pericarditis with systemic involvement, especially in the severe forms.•Acute pericarditis with fever, elevated CRP and particularly pleuropulmonary involvement shows strong similarities with systemic autoinflammatory diseases associated to inflammosome activation.•Neutrophilia, lymphopenia and high neutrophil/lymphocyte ratio are other features of this subset.•Correct recognition of this phenotype might help clinicians to reach appropriate diagnoses, avoiding delays, and on the other hand to individuate possible candidates for anti IL-1 therapies. This cohort study describes a systemic phenotype of pericarditis, comparing this phenotype with other forms of pericarditis. Patients in our center were enrolled in a prospectively maintained registry from 2019 to 2022. 412 patients with idiopathic recurrent pericarditis were analyzed. “Systemic inflammatory” subset was defined as the presence of all the following criteria: fever ≥38C°, CRP ≥2 times normal values, pleural effusion detected with any imaging techniques. The absence of any of the 3 criteria was defined as “isolated” subset. We found that 211 (51.2%) of 412 patients (188 female) presented the systemic subset and the variables significantly associated with this subset in univariate analysis (p