Severe Rheumatic Carditis Associated with Idiopathic Nephrotic Syndrome in a Child: A Rare Case Report

Abstract

Background: Rheumatic carditis is a severe immune-mediated complication of group A beta-hemolytic streptococcal infection, while idiopathic nephrotic syndrome is the most common glomerular disease in childhood. The simultaneous occurrence of these two conditions has not been previously reported. Case Presentation: We report the case of a 5-year-old boy admitted for generalized edema and respiratory distress following a recent episode of tonsillitis. Clinical evaluation and investigations revealed severe decompensated rheumatic carditis associated with idiopathic nephrotic syndrome. Echocardiography showed dilation of all four cardiac chambers, biventricular systolic dysfunction, and multiple valvular regurgitations. Laboratory findings revealed nephrotic-range proteinuria and hypoalbuminemia, with elevated antistreptolysin O titers. Management: The patient was treated with systemic corticosteroids, diuretics, an angiotensin-converting enzyme inhibitor, and antibiotic therapy, including secondary prophylaxis with benzathine penicillin. Outcome: The clinical course was favorable, with rapid resolution of edema, improvement in respiratory symptoms, normalization of cardiac findings, and complete disappearance of proteinuria within one month of treatment. Conclusion: This case represents the first reported association of severe rheumatic carditis and idiopathic nephrotic syndrome in a child. It highlights the potential for multisystem immune-mediated complications following streptococcal infection and underscores the importance of early recognition and appropriate management in pediatric patients.