Case Report: Simil-Appendicitis Presentation May Precede Cardiac Involvement in MIS-C Patient.

Introduction: Multisystem inflammatory syndrome in children (MIS-C) is a new clinical entity characterized by a systemic hyperinflammation triggered by SARS-CoV-2 infection in children and adolescents. This condition could potentially involve all organs with main complications concerning cardiovascular system. Despite up to 90% of patients complain gastrointestinal symptoms (nausea, vomit, and diarrhea), a presentation mimicking acute appendicitis has rarely been reported, and can be the presenting feature of the disease, potentially leading to misdiagnosis and delayed treatment. Case Description: A 15-year-old boy presented to the Emergency Department for a 2-day history of fever, vomiting, and mild abdominal pain. One month before, the patient complained ageusia and anosmia while his mother tested positive for Sars-CoV2 nasopharyngeal swab. At admission, laboratory tests showed leukocytosis with lymphopenia and elevation of inflammatory markers, while cardiac enzymes, electrocardiogram and echocardiography were unremarkable. An abdominal ultrasound displayed a thickening of terminal ileus and cecum with ascites. Because of the worsening abdominal pain and a physical examination suggestive of acute appendicitis, a laparoscopy was performed but no surgical condition was found. After surgery, fever and generalized malaise persisted, so a cardiac evaluation was repeated, showing a relevant increase in inflammatory markers and cardiac enzymes. Electrocardiogram demonstrated a QTc prolongation with mild decrease in left ventricular ejection fraction at echocardiogram. A MIS-C was diagnosed and intravenous immunoglobulin along with a steroid treatment started. After 36 h, the patient presented a complete clinical recovery with fever cessation. Cardiac anomalies normalized in 3 weeks. Conclusion: MIS-C has been defined as a systemic inflammation, involving at least two organs, after a previous SARS-CoV2 infection in children and adolescents. Physicians should be aware that while gastrointestinal manifestations are common, a pseudo appendicitis presentation may also occur, leading to misdiagnosis and delayed treatment. This report suggests that in patients with symptoms suggestive of an acute appendicitis, the presence of lymphopenia, hypoalbuminemia and ultrasound images of terminal ileus inflammation, should raise the suspect for MIS-C even without initial overt signs of cardiac involvement.