293 - MIS-C posing as common gastrointestinal disorders in a pediatric patient leading to delayed diagnosis and treatment

Multisystem Inflammatory Syndrome in Children (MIS-C) is a hyperinflammatory disease that follows COVID-19 infection. Diagnostic criteria include age less than 21 years, illness leading to hospitalization, fever for 24 hours, laboratory evidence of inflammation, multisystem organ involvement, and evidence of recent COVID-19 infection. Most patients present with constitutional, cardiac, and gastrointestinal symptoms.

Objective: To describe a case of MIS-C which presented with solely gastrointestinal symptoms

Design/Methods: Retrospective chart review, review of current literature

Results: A 10-year-old male with recent COVID-19 infection, six weeks prior, presented with five days of fever, vomiting, diarrhea, and right lower quadrant pain. No mucocutaneous, respiratory, neurological, or cardiac symptoms were present. Given initial concerns for appendicitis, an abdominal MRI was performed, revealing a non-dilated appendix with wall thickening and restricted diffusion of the terminal ileum. Laboratory evaluation showed moderately elevated inflammatory markers with normal gastrointestinal PCR, troponin, brain natriuretic peptide, and respiratory viral panel. Inflammatory bowel disease was considered, and MRE demonstrated diffuse inflammation of the small bowel and colon. Endoscopy was planned; however, on day 9 of illness, he remained febrile and developed nonexudative conjunctivitis, scrotal pain, and scrotal edema. Repeat troponin, BNP, and inflammatory markers were markedly elevated. He developed fluid resistant hypotension and was transferred to the intensive care unit. Echocardiogram showed mild mitral and tricuspid regurgitation and a left ventricular ejection fraction of 55%. MIS-C was diagnosed, and he was started on methylprednisolone and intravenous immunoglobulin with an initial response. He remained persistently febrile prompting a trial of anakinra which resulted in dramatic clinical and laboratory improvement. He was discharged on day 15 of symptoms with low-dose aspirin and prednisolone.

Conclusion(s): Several cases of MIS-C in the literature have noted predominantly gastrointestinal manifestations without multisystem involvement. Our patient presented with gastrointestinal symptoms and fever, prompting evaluation for appendicitis, infectious ileitis, and inflammatory bowel disease. Not until day 9 of symptoms did he demonstrate multisystem involvement. A high index of suspicion for MIS-C is necessary to prevent misdiagnosis, delayed diagnosis, and unnecessary procedures in children with solely gastrointestinal symptoms preceded by recent COVID-19 infection