Cardiac Tamponade as a Rare Presentation of Adult-Onset Still's Disease.

Adult-onset Still's disease (AOSD) is a rare inflammatory disease that affects multiple organ systems. Efforts have been made to study the course of the illness and possible treatment options. Cardiac tamponade is a rare and life-threatening complication of AOSD that can be the initial presentation of the disease. We report a 34-year-old patient who presented with a picture of cardiac tamponade and underwent emergency pericardiocentesis. Upon further investigations, the diagnosis of AOSD was made based on Yamaguchi criteria. Furthermore, he showed significant improvement following treatment with prednisolone, methotrexate, and tocilizumab. Our case provides evidence that AOSD should be considered in the differential diagnosis of cardiac tamponade and how prompt treatment of AOSD can effectively prevent potentially fatal complications.