A Case of 1-Month Fever Caused by CMV Infection in a Patient With MIS-C Treated With IVIG, Infliximab, and High-Dose Methylprednisolone

Multisystem inflammatory syndrome in children (MIS-C) is a rare complication of coronavirus disease 2019 (COVID-19), causing multi-organ damage affecting the heart, lungs, kidneys, digestive tract, and nervous system.As the cases of MIS-C have been increasing following the COVID-19 pandemic, the importance of appropriate management for MIS-C is becoming increasingly apparent.Immunomodulating agents such as anakinra, infliximab, and steroids are regarded as supplementary therapy to the first-line treatment with intravenous immunoglobulin.However, these immunomodulating therapies can potentially precipitate opportunistic infections, including those caused by cytomegalovirus (CMV), Epstein-Barr virus, and tuberculosis, or increase the risk of co-infections.Herein, we report a case of a 3-year-old boy who was treated with immunoglobulin, infliximab, and high-dose methylprednisolone for MIS-C, and subsequently developed a persistent fever lasting 32 days caused by a CMV infection.