Acute febrile illness in a teenage female with history of Graves' disease.

Thyroid storm is a rare, life-threatening condition that is usually precipitated by Graves' disease in children and adolescents. COVID-19 (SARS-CoV-2) can cause multisystem inflammatory syndrome in children (MIS C), which shares some features of Graves' disease. We present a case of acute thyroid storm following SARS-CoV-2 infection in a 16-year-old female with poorly controlled Graves' disease. She initially presented to the emergency department for fever and palpitations. Initial laboratory results suggested thyroid storm, for which she was started on propranolol. She remained tachycardic with new gallop rhythm on exam. An echocardiogram demonstrated a depressed left ventricular ejection fraction and mild pulmonary hypertension. Her SARS-CoV-2 antibodies were positive. She was started on intravenous immunoglobulin for suspected MIS-C. She responded to combined treatment of thyroid storm and MIS-C. She was discharged home on propranolol, methimazole, cholestyramine and aspirin.