Baffling case of a patient with history of lupus in a COVID-19 pandemic

Systemic lupus erythematosus (SLE) is an autoimmune disease with a myriad of clinical presentations and periodic flares. We present a case of a young lady with a history of SLE who presented with constitutional symptoms 1 week after starting Isoniazid and Rifampin for treatment of latent TB. Her presentation shared similarities with several diseases including TB lymphadenitis, SLE flare, Kikuchi-Fujimoto Disease (KFD) and hemophagocytic lymphohistiocytosis (HLH) posing a diagnostic dilemma. Additionally, she presented not long after the onset of the global COVID-19 pandemic, further expanding the differential diagnosis. She was ultimately diagnosed with a severe SLE flare caused by rifampin induced suppression of the CYP3A4 system, thereby reducing the therapeutic efficacy of steroids. This case highlights the deadly potential of drug–drug interactions, especially in patients with autoimmune conditions.