biostudies-literatureUnknown12Lim DJ<h4>Introduction</h4>Bacterial pericarditis is rare in the antibiotic era but remains potentially fatal due to rapid progression and high mortality. Herein, we report an unusual case of methicillin-sensitive <i>Staphylococcus aureus</i> (MSSA) pericarditis with a transudative pleural effusion in a patient with poorly controlled type 2 diabetes mellitus (DM), illustrating the diagnostic and therapeutic challenges in a complex patient.<h4>Patient concerns and clinical findings</h4>A 47-year-old female patient with a history of presumptive ischemic cardiomyopathy, uncontrolled DM (a glycated hemoglobin level of 14.2%), and treated pulmonary tuberculosis (TB) presented with pleuritic chest tightness, fever, and dyspnea. Examinations and investigations revealed a moderate-to-large pericardial eFrontiers in cardiovascular medicine1674940https://www.ebi.ac.uk/biostudies/studies/S-EPMC12660183biostudies-literatureCase Report: Acute methicillin-sensitive &lt;i&gt;Staphylococcus aureus&lt;/i&gt; pericarditis in a diabetic patient.PMC12660183Sng ECYChai SCRuan XUy FMHuang WLLim DJYii ASoo IXKhoo JNLu RfalseCase Report: Acute methicillin-sensitive &lt;i&gt;Staphylococcus aureus&lt;/i&gt; pericarditis in a diabetic patient.<h4>Introduction</h4>Bacterial pericarditis is rare in the antibiotic era but remains potentially fatal due to rapid progression and high mortality. Herein, we report an unusual case of methicillin-sensitive <i>Staphylococcus aureus</i> (MSSA) pericarditis with a transudative pleural effusion in a patient with poorly controlled type 2 diabetes mellitus (DM), illustrating the diagnostic and therapeutic challenges in a complex patient.<h4>Patient concerns and clinical findings</h4>A 47-year-old female patient with a history of presumptive ischemic cardiomyopathy, uncontrolled DM (a glycated hemoglobin level of 14.2%), and treated pulmonary tuberculosis (TB) presented with pleuritic chest tightness, fever, and dyspnea. Examinations and investigations revealed a moderate-to-large pericardial e2025-01-01T00:00:00Z20252026-06-05T21:19:55.04Z2026-05-22T03:08:49.646ZS-EPMC126601834132248910.3389/fcvm.2025.1674940