Idiopathic Pericardial Effusions in Children: Workup and Final Diagnoses

Pediatric idiopathic pericardial effusions are common and often have a prolonged clinical course. We hypothesized that these effusions have no standardized diagnostic workup, and ultimately have a final etiology not initially appreciated. To test these hypotheses, a hospital system-wide retrospective (1/1/1990–10/1/2019) cohort study of pericardial effusions in children ( 1 readmission in 12%. Resolution of effusion occurred in 83% of patients within a median of 1 admission (range 1–4). Of those effusions initially deemed idiopathic, 12/42 (29%) were later found to have an underlying etiologic diagnosis including: autoimmune (7, 58%), neoplastic (2, 16%), infectious (2, 16%), and renal (1, 8%). Children initially diagnosed with idiopathic pericardial effusions have an underlying etiologic diagnosis 29% of the time, and a standardized workup may prevent delays in definitive diagnosis and treatment.