RECURRENT PLEUROPERICARDITIS ASSOCIATED WITH MESALAZINE THERAPY MASKED BY STEROID USE

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Demiröz H., ERUZUN H., Çakmak H. D., Ulusoy A. C., Ketenci Y. B., Akca M., ...Daha Fazla

European Journal of Case Reports in Internal Medicine, cilt.13, sa.5, 2026 (Scopus)

Özet

Introduction: Mesalazine is a cornerstone therapy for ulcerative colitis (UC). Although generally safe, it can cause rare but life-threatening cardiopulmonary complications such as pleuropericarditis. Case description: We report on a patient with a UC flare who presented with dyspnoea, where concurrent pericardial and pleural effusions were detected. The inflammatory response was likely suppressed by concomitant corticosteroid therapy, which masked the clinical manifestations of mesalazine-induced serositis and delayed diagnosis. Two years later, the patient re-presented with recurrent massive pericardial effusion causing tamponade physiology and pleural effusion. Pericardial fluid analysis revealed a haemorrhagic, neutrophil-dominant profile (95% polymorphonuclear leukocyte, mimicking bacterial infection rather than the typically described eosinophilic pattern. Extensive cultures were negative. Following the discontinuation of mesalazine, rapid clinical and radiologic improvement was observed, confirming drug-induced pleuropericarditis. Discussion: This case highlights that mesalazine-associated pleuropericarditis can be obscured by corticosteroids, leading to diagnostic delays. Furthermore, sterile inflammatory reactions to mesalazine can present with atypical neutrophilic features resembling bacterial infection, necessitating a high index of suspicion in inflammatory bowel disease patients presenting with serositis.