Asymptomatic SARS-COV2 Infection or COVID-19 vaccination effect for severe multisystem inflammatory syndrome in a 6-year-old girl: case report and review of the literature

This case report and literature review discuss a 6-year-old girl who developed severe multisystem inflammatory syndrome in children (MIS-C) 30 days after receiving her second dose of the COVID-19 vaccine, despite no prior detected SARS-CoV-2 infection. She presented with fever, abdominal pain, rash, and other symptoms, and was diagnosed with MIS-C through positive anti-SARS-CoV-2 antibodies. Treatment with intravenous immunoglobulins and methylprednisone led to initial improvement, but she later developed pancreatitis and severe neurological symptoms, which resolved after 2 months. She also experienced transient hair loss (telogen effluvium) 3 months post-symptom onset. After 12 months, she showed no symptomatic sequelae. The case suggests a potential link between COVID-19 vaccination and MIS-C in young children and underscores the importance of prompt diagnosis and treatment.