Multisystem inflammatory syndrome in children (MIS-C) is a potentially life-threatening childhood disease caused by
SARS-CoV-2 infection, manifested by the persistence of
fever and multi-organ dysfunction, elevated inflammatory markers, and the lack of an alternative diagnosis. It is still unknown if vaccination can precipitate or abrogate MIS-C or if a natural
infection preceding or occurring at the time of vaccination plays any role. We present one case of MIS-C in a 16-year-old girl who was fully immunized against
COVID-19 (Pfizer), with the second dose received three weeks prior to onset of the disease. She had no history of
COVID-19 disease or contact with
COVID-19 patients. At admission, she was somnolent, pale, and dehydrated, with cyanotic lips and cold extremities; she was hypotensive with
tachycardia and poorly palpable pulses. Initial laboratory results revealed elevated levels of inflammatory markers, and high level of SARS-CoV-2
IgG spike
antibodies, while testing for SARS-CoV-2 acute
infection and other inflammatory etiologies were negative.
Vaccine-related MIS-C was suspected in our case due to the development of MIS-C three weeks following the second dose of the
COVID-19 mRNA vaccine, the absence of previous
infection or exposure to SARS-CoV-2, and a positive result for
IgG anti-spike (S)
antibodies.