Multisystem post COVID-19 syndrome and its difficult etiological diagnosis

A clinical case

Abstract

SARS-CoV-2 affects a low number of pediatric patients, most asymptomatic or with mild respiratory compromise and favorable evolution. However, in previously healthy children, Multisystem Inflammatory Syndrome (SIM-C) or Kawasaki-like Syndrome(Kawasaki-like) may appear linked to the COVID-19 disease, progressing to shock and requiring admission to the intensive care unit.

We present the case of an adolescent with an environmental history of SARS-CoV-2 37 days prior to her admission, who was not tested at that time. She had received the first dose of Pfizer vaccine 15 days before the presentation of digestive symptoms with abdominal pain and fever. She had a negative Covid-19 antigen test and viral PCR. After an exploratory laparoscopy, on the sixth day of fever and pain, she developed bilateral non-suppurative conjunctivitis and a rash on the chest, odynophagia, asthenia, and coated tongue with the Kawasaki phenotype. The anti-spike IgG serology was positive and the IgM negative, with elevated inflammatory parameters, so a post-COVID-19 multisystem syndrome was suggested. She received treatment with intravenous immunoglobulin, ASA and methylprednisolone. In order to rule out the possibility of an event allegedly caused by vaccination or immunization (ESAVI), the serological search for SARS-CoV-2 was carried out through a qualitative study, looking for antibodies that are not generated with the Pfizer vaccine. The result was positive. Therefore, we confirmed the post-Covid etiology and ruled out the ESAVI etiology, and also performed the quantitative study of the anti-spike antibodies, which showed a decrease one month after the debut