COVID-19-related Multisystem Inflammatory Syndrome in a Young Adult

Introduction: A condition called multisystem inflammatory syndrome in children (MIS-C), related to past SARS-CoV-2 infection, has been described in a series of cases. There is a growing body of evidence suggesting a similar entity in adults (MIS-A). We report a case of a young adult with a hyperinflammatory systemic syndrome with end-organ lesions and a recent SARS-CoV-2 infection. Methods and Procedures: The patient developed end-organ lesions in the respiratory, cardiovascular, digestive, haematological and mucocutaneous systems. A wide diagnostic work-up did not find any specific aetiology (autoimmunity, neoplastic or infectious). There was evidence of past SARS-CoV-2 infection with positive autoimmune titres (positive IgG). A presumptive diagnosis of MIS-A was made and treatment with corticosteroids was introduced with improvement. Discussion: COVID-19-related multisystem inflammatory syndrome in adults is still an unknown entity with no diagnostic criteria or treatment guidelines. Much of what is known is inferred from what we already know about MIS-C. There have been several reported cases with severity ranging from mild to severe. The mechanisms behind this condition are still largely unknown. More evidence is needed to establish diagnosis and treatment.