RESUMEN
Myasthenia gravis (MG) is an autoimmune disease that induces skeletal muscle weakness, affecting different muscle groups. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), became both a diagnostic and a therapeutic challenge during the pandemic. The effects of COVID-19 are not only limited to the acute symptoms but also to the post-infectious sequelae. We present the case of a 30-year-old Caucasian woman, with no significant medical history, who presented to the emergency room with acute respiratory failure. The patient tested positive for SARS-CoV-2 with a rapid antigen test and during hospitalization developed a myasthenic crisis, ultimately being diagnosed with seropositive MG.