A Rare Case of Effusive Pericarditis: Overlap Syndrome.

Systemic autoimmune disease contributes up to ~22% of cases of pericarditis with known etiology. Systemic lupus erythematosus (SLE) is a multisystem disease with a variety of clinical presentations and manifestations. Since the underlying mechanism for pericardial involvement differs with each systemic disease, this leads to poor understanding of its management. However, it is rare for acute pericarditis to be the leading symptom at the time of diagnosis of SLE, occurring in up to 1% of patients. This is a case report of a 21-year-old female who presented with breathlessness and pedal edema, who was previously misdiagnosed with tubercular pericarditis and was started on antitubercular treatment (ATT). Now she is diagnosed with autoimmune pericarditis with SLEoverlap syndrome. Pericarditis, being the most common cardiac manifestation of SLE, has an incidence ranging between 11 and 54%. Knowledge of such association is necessary to avoid misdiagnosis.