Does Multisystem Inflammatory Syndrome Only Mimic Acute Appendicitis in Children or Can It Coexist: When Should We Suspect MIS-C?

Case Report: Acute abdomen and large mesenteric mass as another face of multisystem inflammatory syndrome in an adolescent child: measure twice, act once!

Introduction

During the Covid-19 era, acute abdomen and mesenteric lymphadenopathy were encountered as frequent mimic of appendicitis. This phenomenon can further complicate the diagnosis of acute abdominal conditions, not solely due to bacterial or viral intestinal infections but also attributable to post-infectious acute inflammatory states resulting in either undertreatment of inflammatory conditions or unnecessary surgery.

Case presentation

In this case study, we present the case of an 11-year-old female who initially presented with fever and right lower quadrant abdominal pain, raising concerns of appendicitis. However, upon further investigation, it was revealed that she harbored a sizable mesenteric mass. Subsequent biopsy results unveiled a significant necrotic mesenteric lymphadenitis. Notably, this patient fulfilled the criteria for Multisystem Inflammatory Syndrome in Children (MIS-C), a condition that manifested following persistent postoperative fever. Remarkably, the patient exhibited a highly favorable response to the treatment administered. This clinical scenario presents an atypical manifestation of MIS-C, as the patient displayed a substantial mesenteric mass alongside symptoms mimicking appendicitis, within the context of an acute abdomen.

Conclusion

Clinicians should consider MIS-C and other post-infectious inflammatory conditions in mind when diagnosing acute abdominal cases. The presented case underscores the importance of recognizing atypical presentations of MIS-C that can mimic appendicitis, sometimes necessitating surgical resection of a large lymph node. We propose diagnostic flow chart to aid in the differentiation of acute bacterial appendicitis from MIS-C.

Coincidental or mimicking acute appendicitis secondary to MIS-C associated with SARS-CoV-2: A case report

The predominant organic system involved in multisystem inflammatory syndrome in children associated with COVID-19 is the gastrointestinal system, which is observed in almost 90% of patients. Gastrointestinal symptoms can mimic acute appendicitis. There have been a few cases of misdiagnosed multisystem inflammatory syndrome in children associated with SARS-CoV-2 as appendicitis, and a few concomitant cases of a multisystem inflammatory syndrome associated with acute appendicitis during the COVID-19 pandemic. Here, we present the case of an 11-year-old girl who presented to our Intensive Care Unit with a 2-day history of fever, generalized abdominal pain, and vomiting. The clinical findings resulted in a clinical suspicion of acute appendicitis and subsequent surgery. While postoperatively, she became critically ill, and she was diagnosed with the multisystem inflammatory syndrome in children associated with COVID-19. When diagnosing children with acute appendicitis, healthcare professionals, especially pediatricians and surgeons, must pay attention to the multisystem inflammatory syndrome linked to the SARS-CoV-2 infection.